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Linux Build Service Account and others added 30 commits December 29, 2019 03:13
Add support to read default value of interrupt moderation
interval from devicetree parameter "qcom,gadget-imod-val".

Change-Id: I8e4ecaebdb67a13cc29fac9fef5dafea7f30b0e3
Signed-off-by: Ajay Agarwal <ajaya@codeaurora.org>
This reverts commit b506ddc ("driver: soc: wcnss: fix WCNSS
SSR make device reboot issue"). This is needed to not free up
regulatory source.

Change-Id: Ibf41d140e727987a234c37c0466e007eb7270cf1
CRs-Fixed: 2594716
Signed-off-by: Dundi Raviteja <dundi@codeaurora.org>
Added camera dtsi changes for MSM8953 QRD.

Change-Id: I1ed04593f60f908332b774d38a4101d9b91cf67b
Signed-off-by: Vandana Jain <vandja@codeaurora.org>
Updated correct value of cam-vdig-supply for MSM8953
QRD Back Camera.

Change-Id: Ied9ec629cb6a3ebab06518e4489e284473e80377
Signed-off-by: Vandana Jain <vandja@codeaurora.org>
During lazy dma_map_sg, only some entries of the caller's sg list
are stored in the msm_iommu_map->sgl. And lazy dma_unmap_sg uses
this incomplete sgl to perform sg_list walk to determine the total
iova size to unmap (all entries/segments are mapped into a single
contiguous iova). Since sg->page_link is missing, the sg_list walk
ends up into null pointer dereference kernel crash:

	BUG: Unable to handle kernel NULL pointer dereference at virtual
	address 00000018
	PC is at iommu_dma_unmap_sg+0x4c/0xdc
	[...]
	iommu_dma_unmap_sg+0x4c/0xdc
	__iommu_unmap_sg_attrs+0x64/0x6c
	msm_iommu_map_release+0x154/0x164
	msm_dma_buf_freed+0x168/0x3c8
	_ion_buffer_destroy+0x30/0x88
	ion_buffer_put+0x40/0x50
	ion_handle_destroy+0xec/0x10c
	ion_handle_put_nolock+0x40/0x50
	ion_ioctl+0x2ec/0x4d4
	do_vfs_ioctl+0xd0/0x85c
	SyS_ioctl+0x90/0xa4
	el0_svc_naked+0x24/0x28

Hence, clone/duplicate the caller's sg list into msm_iommu_map->sgl.
Also, update lazy map/unmap_sg to check DMA_ATTR_SKIP_CPU_SYNC to
skip cache maintenance only if asked for.

Change-Id: Idb7bd52d84d27ad0c7873208a3e25129f20d07da
Signed-off-by: Sudarshan Rajagopalan <sudaraja@codeaurora.org>
[vinmenon@codeaurora.org: removed unrelated CMO change]
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
This adds support for the DisplayPort CEC-Tunneling-over-AUX
feature that is part of the DisplayPort 1.3 standard.

Unfortunately, not all DisplayPort/USB-C to HDMI adapters with a
chip that has this capability actually hook up the CEC pin, so
even though a CEC device is created, it may not actually work.

Change-Id: I8dc417c30ee387cbbd4fd29059c79e9457896291
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180711132909.25409-2-hverkuil@xs4all.nl
Git-commit: 2c6d1fffa1d9b0a5b5ac1a23be9ad64abe60910d
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
[vvalluru@codeaurora.org: resolved merge conflicts]
Signed-off-by: Venkata Prahlad Valluru <vvalluru@codeaurora.org>
possibility of OOB access on device->response_pkt in
__response_handler. for e.x if msg queue contains 1000
messages and all 1000 were read and queue is empty.
So __get_q_size api will return zero and _iface_msgq_read
will go in an infinite loop, even if packet_count
== max_packets.

Change-Id: I3c0fb095feff0ba5d4d6dab65ed9d5111f1b6f05
Signed-off-by: Govindaraj Rajagopal <grajagop@codeaurora.org>
commit [2] changed cancel_delayed_work to cancel_delayed_work_sync to
avoid a use-after-free issue. However, cancel_delayed_work_sync could be
called insides the WQ causing deadlock [1].

[1]
[54109.642398] c0   1162 kworker/u17:1   D    0 11030      2 0x00000000
[54109.642437] c0   1162 Workqueue: thermal_passive_wq thermal_zone_device_check
[54109.642447] c0   1162 Call trace:
[54109.642456] c0   1162  __switch_to+0x138/0x158
[54109.642467] c0   1162  __schedule+0xba4/0x1434
[54109.642480] c0   1162  schedule_timeout+0xa0/0xb28
[54109.642492] c0   1162  wait_for_common+0x138/0x2e8
[54109.642511] c0   1162  flush_work+0x348/0x40c
[54109.642522] c0   1162  __cancel_work_timer+0x180/0x218
[54109.642544] c0   1162  handle_thermal_trip+0x2c4/0x5a4
[54109.642553] c0   1162  thermal_zone_device_update+0x1b4/0x25c
[54109.642563] c0   1162  thermal_zone_device_check+0x18/0x24
[54109.642574] c0   1162  process_one_work+0x3cc/0x69c
[54109.642583] c0   1162  worker_thread+0x49c/0x7c0
[54109.642593] c0   1162  kthread+0x17c/0x1b0
[54109.642602] c0   1162  ret_from_fork+0x10/0x18
[54109.643051] c0   1162 kworker/u17:2   D    0 16245      2 0x00000000
[54109.643067] c0   1162 Workqueue: thermal_passive_wq thermal_zone_device_check
[54109.643077] c0   1162 Call trace:
[54109.643085] c0   1162  __switch_to+0x138/0x158
[54109.643095] c0   1162  __schedule+0xba4/0x1434
[54109.643104] c0   1162  schedule_timeout+0xa0/0xb28
[54109.643114] c0   1162  wait_for_common+0x138/0x2e8
[54109.643122] c0   1162  flush_work+0x348/0x40c
[54109.643131] c0   1162  __cancel_work_timer+0x180/0x218
[54109.643141] c0   1162  handle_thermal_trip+0x2c4/0x5a4
[54109.643150] c0   1162  thermal_zone_device_update+0x1b4/0x25c
[54109.643159] c0   1162  thermal_zone_device_check+0x18/0x24
[54109.643167] c0   1162  process_one_work+0x3cc/0x69c
[54109.643177] c0   1162  worker_thread+0x49c/0x7c0
[54109.643186] c0   1162  kthread+0x17c/0x1b0
[54109.643195] c0   1162  ret_from_fork+0x10/0x18
[54109.644500] c0   1162 cat             D    0  7766      1 0x00000001
[54109.644515] c0   1162 Call trace:
[54109.644524] c0   1162  __switch_to+0x138/0x158
[54109.644536] c0   1162  __schedule+0xba4/0x1434
[54109.644546] c0   1162  schedule_preempt_disabled+0x80/0xb0
[54109.644555] c0   1162  __mutex_lock+0x3a8/0x7f0
[54109.644563] c0   1162  __mutex_lock_slowpath+0x14/0x20
[54109.644575] c0   1162  thermal_zone_get_temp+0x84/0x360
[54109.644586] c0   1162  temp_show+0x30/0x78
[54109.644609] c0   1162  dev_attr_show+0x5c/0xf0
[54109.644628] c0   1162  sysfs_kf_seq_show+0xcc/0x1a4
[54109.644636] c0   1162  kernfs_seq_show+0x48/0x88
[54109.644656] c0   1162  seq_read+0x1f4/0x73c
[54109.644664] c0   1162  kernfs_fop_read+0x84/0x318
[54109.644683] c0   1162  __vfs_read+0x50/0x1bc
[54109.644692] c0   1162  vfs_read+0xa4/0x140
[54109.644701] c0   1162  SyS_read+0xbc/0x144
[54109.644708] c0   1162  el0_svc_naked+0x34/0x38
[54109.845800] c0   1162 D 720.000s 1->7766->7766 cat [panic]

Fixes commit 1851799e1d29 ("thermal: Fix use-after-free when
unregistering thermal zone device") [2]

Change-Id: I68359026b0fc7c1345a8bbb693a5dc8f19c3f6b1
Signed-off-by: Wei Wang <wvw@google.com>
Link: https://lore.kernel.org/patchwork/patch/1152681/
Patch-mainline: linux-kernel@ Nov. 12, 2019, 20:42:23
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>
Enable external codec (Tasha) for qrd target. Disable internal
codec.

Change-Id: Idc6f344675a1541b47a8a9674b304b697ee09285
CRs-Fixed: 2595101
Signed-off-by: Nikhil Laturkar <nlathuk@codeaurora.org>
Signed-off-by: Bala Kishore Pati <bkpati@codeaurora.org>
* refs/heads/tmp-258971b:
  Linux 4.9.202
  Documentation: Add ITLB_MULTIHIT documentation
  kvm: x86: mmu: Recovery of shattered NX large pages
  kvm: Add helper function for creating VM worker threads
  kvm: mmu: ITLB_MULTIHIT mitigation
  cpu/speculation: Uninline and export CPU mitigations helpers
  x86/bugs: Add ITLB_MULTIHIT bug infrastructure
  KVM: vmx, svm: always run with EFER.NXE=1 when shadow paging is active
  KVM: x86: add tracepoints around __direct_map and FNAME(fetch)
  KVM: x86: Add is_executable_pte()
  KVM: x86: change kvm_mmu_page_get_gfn BUG_ON to WARN_ON
  KVM: x86: remove now unneeded hugepage gfn adjustment
  KVM: x86: make FNAME(fetch) and __direct_map more similar
  kvm: x86: Do not release the page inside mmu_set_spte()
  kvm: Convert kvm_lock to a mutex
  KVM: x86: extend usage of RET_MMIO_PF_* constants
  KVM: x86: simplify ept_misconfig
  x86/speculation/taa: Fix printing of TAA_MSG_SMT on IBRS_ALL CPUs
  x86/tsx: Add config options to set tsx=on|off|auto
  x86/speculation/taa: Add documentation for TSX Async Abort
  x86/tsx: Add "auto" option to the tsx= cmdline parameter
  kvm/x86: Export MDS_NO=0 to guests when TSX is enabled
  x86/speculation/taa: Add sysfs reporting for TSX Async Abort
  x86/speculation/taa: Add mitigation for TSX Async Abort
  x86/cpu: Add a "tsx=" cmdline option with TSX disabled by default
  x86/cpu: Add a helper function x86_read_arch_cap_msr()
  x86/msr: Add the IA32_TSX_CTRL MSR
  KVM: x86: use Intel speculation bugs and features as derived in generic x86 code
  usb: gadget: core: unmap request from DMA only if previously mapped
  MIPS: BCM63XX: fix switch core reset on BCM6368
  Bluetooth: hci_ldisc: Postpone HCI_UART_PROTO_READY bit set in hci_uart_set_proto()
  kvm: mmu: Don't read PDPTEs when paging is not enabled

Change-Id: I011afa22678ebad9d061ed6bb386ca13cfd7bb50
Signed-off-by: jianzhou <jianzhou@codeaurora.org>
* refs/heads/tmp-13ff513:
  Linux 4.9.203
  arm64: uaccess: Ensure PAN is re-enabled after unhandled uaccess fault
  ARM: dts: omap5: Fix dual-role mode on Super-Speed port
  spi: rockchip: initialize dma_slave_config properly
  mac80211: minstrel: fix CCK rate group streams value
  misc: cxl: Fix possible null pointer dereference
  hwmon: (ina3221) Fix INA3221_CONFIG_MODE macros
  hwmon: (pwm-fan) Silence error on probe deferral
  orangefs: rate limit the client not running info message
  ARM: 8802/1: Call syscall_trace_exit even when system call skipped
  spi: spidev: Fix OF tree warning logic
  gpio: syscon: Fix possible NULL ptr usage
  x86/kexec: Correct KEXEC_BACKUP_SRC_END off-by-one error
  media: cx231xx: fix potential sign-extension overflow on large shift
  GFS2: Flush the GFS2 delete workqueue before stopping the kernel threads
  media: isif: fix a NULL pointer dereference bug
  printk: Give error on attempt to set log buffer length to over 2G
  mfd: ti_am335x_tscadc: Keep ADC interface on if child is wakeup capable
  backlight: lm3639: Unconditionally call led_classdev_unregister
  proc/vmcore: Fix i386 build error of missing copy_oldmem_page_encrypted()
  s390/kasan: avoid vdso instrumentation
  bcache: recal cached_dev_sectors on detach
  reset: Fix potential use-after-free in __of_reset_control_get()
  fbdev: sbuslib: integer overflow in sbusfb_ioctl_helper()
  fbdev: sbuslib: use checked version of put_user()
  iwlwifi: mvm: don't send keys when entering D3
  ACPI / SBS: Fix rare oops when removing modules
  crypto: mxs-dcp - Fix AES issues
  crypto: mxs-dcp - Fix SHA null hashes and output length
  x86/olpc: Fix build error with CONFIG_MFD_CS5535=m
  Input: silead - try firmware reload after unsuccessful resume
  Input: st1232 - set INPUT_PROP_DIRECT property
  dmaengine: ioat: fix prototype of ioat_enumerate_channels
  NFSv4.x: fix lock recovery during delegation recall
  i2c: brcmstb: Allow enabling the driver on DSL SoCs
  clk: samsung: Use clk_hw API for calling clk framework from clk notifiers
  brcmfmac: fix full timeout waiting for action frame on-channel tx
  brcmfmac: reduce timeout for action frame scan
  cpu/SMT: State SMT is disabled even with nosmt and without "=force"
  mtd: physmap_of: Release resources on error
  USB: serial: cypress_m8: fix interrupt-out transfer length
  KVM: PPC: Book3S PR: Exiting split hack mode needs to fixup both PC and LR
  ALSA: hda/sigmatel - Disable automute for Elo VuPoint
  media: pxa_camera: Fix check for pdev->dev.of_node
  ata: ep93xx: Use proper enums for directions
  ACPICA: Never run _REG on system_memory and system_IO
  IB/mlx4: Avoid implicit enumerated type conversion
  IB/mthca: Fix error return code in __mthca_init_one()
  ixgbe: Fix crash with VFs and flow director on interface flap
  mtd: rawnand: sh_flctl: Use proper enum for flctl_dma_fifo0_transfer
  powerpc/pseries: Fix how we iterate over the DTL entries
  powerpc/pseries: Fix DTL buffer registration
  cxgb4: Use proper enum in IEEE_FAUX_SYNC
  cxgb4: Use proper enum in cxgb4_dcb_handle_fw_update
  mei: samples: fix a signedness bug in amt_host_if_call()
  dmaengine: timb_dma: Use proper enum in td_prep_slave_sg
  dmaengine: ep93xx: Return proper enum in ep93xx_dma_chan_direction
  nl80211: Fix a GET_KEY reply attribute
  usb: gadget: udc: fotg210-udc: Fix a sleep-in-atomic-context bug in fotg210_get_status()
  ath9k: fix reporting calculated new FFT upper max
  ata: ahci_brcm: Allow using driver or DSL SoCs
  ath10k: fix vdev-start timeout on error
  arm64/numa: Report correct memblock range for the dummy node
  kvm: arm/arm64: Fix stage2_flush_memslot for 4 level page table
  SUNRPC: Fix priority queue fairness
  f2fs: return correct errno in f2fs_gc
  ARM: dts: omap5: enable OTG role for DWC3 controller
  net: xen-netback: fix return type of ndo_start_xmit function
  net: ovs: fix return type of ndo_start_xmit function
  libata: have ata_scsi_rw_xlat() fail invalid passthrough requests
  block: introduce blk_rq_is_passthrough
  fbdev: Ditch fb_edid_add_monspecs
  uprobes/x86: Prohibit probing on MOV SS instruction
  kprobes/x86: Prohibit probing on exception masking instructions
  x86/atomic: Fix smp_mb__{before,after}_atomic()
  net: cdc_ncm: Signedness bug in cdc_ncm_set_dgram_size()
  slcan: Fix memory leak in error path
  memfd: Use radix_tree_deref_slot_protected to avoid the warning.
  IB/iser: Fix possible NULL deref at iser_inv_desc()
  fuse: use READ_ONCE on congestion_threshold and max_background
  usb: xhci-mtk: fix ISOC error when interval is zero
  ARM: dts: lpc32xx: Fix SPI controller node names
  arm64: dts: lg: Fix SPI controller node names
  arm64: dts: amd: Fix SPI bus warnings
  scsi: NCR5380: Handle BUS FREE during reselection
  scsi: NCR5380: Don't call dsprintk() following reselection interrupt
  scsi: NCR5380: Don't clear busy flag when abort fails
  scsi: NCR5380: Check for invalid reselection target
  scsi: NCR5380: Use DRIVER_SENSE to indicate valid sense data
  scsi: NCR5380: Clear all unissued commands on host reset
  crypto: fix a memory leak in rsa-kcs1pad's encryption mode
  crypto: s5p-sss: Fix Fix argument list alignment
  Bluetooth: L2CAP: Detect if remote is not able to use the whole MPS
  ARM: dts: realview: Fix SPI controller node names
  EDAC: Raise the maximum number of memory controllers
  net: smsc: fix return type of ndo_start_xmit function
  ARM: dts: paz00: fix wakeup gpio keycode
  ARM: tegra: apalis_t30: fix mmc1 cmd pull-up
  ARM: dts: tegra30: fix xcvr-setup-use-fuses
  scsi: libsas: always unregister the old device if going to discover new
  vfio/pci: Mask buggy SR-IOV VF INTx support
  vfio/pci: Fix potential memory leak in vfio_msi_cap_len
  misc: genwqe: should return proper error value.
  misc: kgdbts: Fix restrict error
  coresight: tmc: Fix byte-address alignment for RRP
  coresight: etm4x: Configure EL2 exception level when kernel is running in HYP
  coresight: Fix handling of sinks
  usb: gadget: uvc: Only halt video streaming endpoint in bulk mode
  usb: gadget: uvc: Factor out video USB request queueing
  phy: phy-twl4030-usb: fix denied runtime access
  usb: gadget: uvc: configfs: Prevent format changes after linking header
  usb: gadget: uvc: configfs: Drop leaked references to config items
  media: davinci: Fix implicit enum conversion warning
  media: au0828: Fix incorrect error messages
  media: pci: ivtv: Fix a sleep-in-atomic-context bug in ivtv_yuv_init()
  MIPS: kexec: Relax memory restriction
  x86/CPU: Use correct macros for Cyrix calls
  net: micrel: fix return type of ndo_start_xmit function
  bnx2x: Ignore bandwidth attention in single function mode
  ARM: dts: marvell: Fix SPI and I2C bus warnings
  cpufeature: avoid warning when compiling with clang
  spi: pic32: Use proper enum in dmaengine_prep_slave_rg
  ARM: dts: ste: Fix SPI controller node names
  ARM: dts: ux500: Fix LCDA clock line muxing
  ARM: dts: ux500: Correct SCU unit address
  f2fs: fix to recover inode's uid/gid during POR
  ARM: dts: am335x-evm: fix number of cpsw
  mlxsw: spectrum: Init shaper for TCs 8..15
  usb: chipidea: Fix otg event handler
  usb: chipidea: imx: enable OTG overcurrent in case USB subsystem is already started
  net: amd: fix return type of ndo_start_xmit function
  net: broadcom: fix return type of ndo_start_xmit function
  net: xilinx: fix return type of ndo_start_xmit function
  net: toshiba: fix return type of ndo_start_xmit function
  power: supply: twl4030_charger: disable eoc interrupt on linear charge
  power: supply: twl4030_charger: fix charging current out-of-bounds
  libfdt: Ensure INT_MAX is defined in libfdt_env.h
  RDMA/i40iw: Fix incorrect iterator type
  powerpc/pseries: Disable CPU hotplug across migrations
  powerpc/64s/hash: Fix stab_rr off by one initialization
  powerpc/iommu: Avoid derefence before pointer check
  serial: mxs-auart: Fix potential infinite loop
  PCI/ACPI: Correct error message for ASPM disabling
  s390/qeth: invoke softirqs after napi_schedule()
  ath9k: Fix a locking bug in ath9k_add_interface()
  ARM: dts: rockchip: Fix erroneous SPI bus dtc warnings on rk3036
  ip_gre: fix parsing gre header in ipgre_err
  kernfs: Fix range checks in kernfs_get_target_path
  component: fix loop condition to call unbind() if bind() fails
  power: supply: max8998-charger: Fix platform data retrieval
  power: reset: at91-poweroff: do not procede if at91_shdwc is allocated
  power: supply: ab8500_fg: silence uninitialized variable warnings
  cxgb4: Fix endianness issue in t4_fwcache()
  pinctrl: at91: don't use the same irqchip with multiple gpiochips
  ARM: dts: socfpga: Fix I2C bus unit-address error
  powerpc/vdso: Correct call frame information
  ARM: dts: qcom: ipq4019: fix cpu0's qcom,saw2 reg value
  llc: avoid blocking in llc_sap_close()
  pinctrl: at91-pio4: fix has_config check in atmel_pctl_dt_subnode_to_map()
  ALSA: intel8x0m: Register irq handler after register initializations
  media: dvb: fix compat ioctl translation
  media: fix: media: pci: meye: validate offset to avoid arbitrary access
  nvmem: core: return error code instead of NULL from nvmem_device_get
  kprobes: Don't call BUG_ON() if there is a kprobe in use on free list
  scsi: pm80xx: Fixed system hang issue during kexec boot
  scsi: pm80xx: Corrected dma_unmap_sg() parameter
  ARM: imx6: register pm_power_off handler if "fsl,pmic-stby-poweroff" is set
  scsi: sym53c8xx: fix NULL pointer dereference panic in sym_int_sir()
  f2fs: fix memory leak of percpu counter in fill_super()
  signal: Properly deliver SIGSEGV from x86 uprobes
  signal: Properly deliver SIGILL from uprobes
  signal: Always ignore SIGKILL and SIGSTOP sent to the global init
  ath9k: add back support for using active monitor interfaces for tx99
  dmaengine: dma-jz4780: Further residue status fix
  dmaengine: dma-jz4780: Don't depend on MACH_JZ4780
  ARM: dts: omap3-gta04: keep vpll2 always on
  ARM: dts: omap3-gta04: make NAND partitions compatible with recent U-Boot
  ARM: dts: omap3-gta04: fix touchscreen tsc2007
  ARM: dts: omap3-gta04: tvout: enable as display1 alias
  ARM: dts: omap3-gta04: fixes for tvout / venc
  ARM: dts: omap3-gta04: give spi_lcd node a label so that we can overwrite in other DTS files
  of: make PowerMac cache node search conditional on CONFIG_PPC_PMAC
  ASoC: Intel: hdac_hdmi: Limit sampling rates at dai creation
  mips: txx9: fix iounmap related issue
  ath10k: wmi: disable softirq's while calling ieee80211_rx
  ARM: dts: exynos: Disable pull control for S5M8767 PMIC
  ASoC: sgtl5000: avoid division by zero if lo_vag is zero
  net: lan78xx: Bail out if lan78xx_get_endpoints fails
  rtl8187: Fix warning generated when strncpy() destination length matches the sixe argument
  ARM: dts: pxa: fix power i2c base address
  iwlwifi: mvm: avoid sending too many BARs
  IB/rxe: fixes for rdma read retry
  i40e: Prevent deleting MAC address from VF when set by PF
  i40e: hold the rtnl lock on clearing interrupt scheme
  i40e: use correct length for strncpy
  ARM: dts: exynos: Fix regulators configuration on Peach Pi/Pit Chromebooks
  ARM: dts: exynos: Fix sound in Snow-rev5 Chromebook
  MIPS: BCM47XX: Enable USB power on Netgear WNDR3400v3
  ASoC: dpcm: Properly initialise hw->rate_max
  gfs2: Don't set GFS2_RDF_UPTODATE when the lvb is updated
  ath9k: fix tx99 with monitor mode interface
  ALSA: seq: Do error checks at creating system ports
  cfg80211: Avoid regulatory restore when COUNTRY_IE_IGNORE is set
  ARM: dts: at91/trivial: Fix USART1 definition for at91sam9g45
  arm64: dts: tegra210-p2180: Correct sdmmc4 vqmmc-supply
  ALSA: pcm: signedness bug in snd_pcm_plug_alloc()
  iio: dac: mcp4922: fix error handling in mcp4922_write_raw
  ath10k: fix kernel panic by moving pci flush after napi_disable
  mmc: sdhci-of-at91: fix quirk2 overwrite
  mm: hugetlb: switch to css_tryget() in hugetlb_cgroup_charge_cgroup()
  mm: memcg: switch to css_tryget() in get_mem_cgroup_from_mm()
  iommu/vt-d: Fix QI_DEV_IOTLB_PFSID and QI_DEV_EIOTLB_PFSID macros
  ecryptfs_lookup_interpose(): lower_dentry->d_parent is not stable either
  ecryptfs_lookup_interpose(): lower_dentry->d_inode is not stable
  IB/hfi1: Ensure full Gen3 speed in a Gen4 system
  Input: synaptics-rmi4 - destroy F54 poller workqueue when removing
  Input: synaptics-rmi4 - clear IRQ enables for F54
  Input: synaptics-rmi4 - fix video buffer size
  Input: ff-memless - kill timer in destroy()
  ALSA: usb-audio: not submit urb for stopped endpoint
  ALSA: usb-audio: Fix missing error check at mixer resolution test
  slip: Fix memory leak in slip_open error path
  ax88172a: fix information leak on short answers

  Conflicts:
 	include/linux/libfdt_env.h

Change-Id: I3cd727a3adcd9b3f1979867923992f3d6fcd7dac
Signed-off-by: jianzhou <jianzhou@codeaurora.org>
* refs/heads/tmp-72e8598:
  Linux 4.9.204
  KVM: PPC: Book3S HV: Flush link stack on guest exit to host kernel
  powerpc/book3s64: Fix link stack flush on context switch
  powerpc/64s: support nospectre_v2 cmdline option
  staging: comedi: usbduxfast: usbduxfast_ai_cmdtest rounding error
  USB: serial: option: add support for Foxconn T77W968 LTE modules
  USB: serial: option: add support for DW5821e with eSIM support
  USB: serial: mos7840: fix remote wakeup
  USB: serial: mos7720: fix remote wakeup
  USB: serial: mos7840: add USB ID to support Moxa UPort 2210
  appledisplay: fix error handling in the scheduled work
  USB: chaoskey: fix error case of a timeout
  usb-serial: cp201x: support Mark-10 digital force gauge
  usbip: tools: fix fd leakage in the function of read_attr_usbip_status
  virtio_console: move removal code
  virtio_console: drop custom control queue cleanup
  virtio_console: fix uninitialized variable use
  virtio_ring: fix return code on DMA mapping fails
  virtio_console: allocate inbufs in add_port() only if it is needed
  virtio_console: don't tie bufs to a vq
  virtio_console: reset on out of memory
  media: imon: invalid dereference in imon_touch_event
  media: cxusb: detect cxusb_ctrl_msg error in query
  media: b2c2-flexcop-usb: add sanity checking
  media: uvcvideo: Fix error path in control parsing failure
  cpufreq: Add NULL checks to show() and store() methods of cpufreq
  media: usbvision: Fix races among open, close, and disconnect
  media: vivid: Fix wrong locking that causes race conditions on streaming stop
  media: vivid: Set vid_cap_streaming and vid_out_streaming to true
  l2tp: don't use l2tp_tunnel_find() in l2tp_ip and l2tp_ip6
  nfc: port100: handle command failure cleanly
  x86/speculation: Fix redundant MDS mitigation message
  x86/speculation: Fix incorrect MDS/TAA mitigation status
  x86/insn: Fix awk regexp warnings
  ARC: perf: Accommodate big-endian CPU
  ARM: 8904/1: skip nomap memblocks while finding the lowmem/highmem boundary
  ocfs2: remove ocfs2_is_o2cb_active()
  cpufreq: Skip cpufreq resume if it's not suspended
  arm64: fix for bad_mode() handler to always result in panic
  dm: use blk_set_queue_dying() in __dm_destroy()
  ath9k_hw: fix uninitialized variable data
  KVM: MMU: Do not treat ZONE_DEVICE pages as being reserved
  Bluetooth: Fix invalid-free in bcsp_close()
  mm/memory_hotplug: Do not unlock when fails to take the device_hotplug_lock
  spi: omap2-mcspi: Fix DMA and FIFO event trigger size mismatch
  PCI: keystone: Use quirk to limit MRRS for K2G
  pinctrl: zynq: Use define directive for PIN_CONFIG_IO_STANDARD
  pinctrl: lpc18xx: Use define directive for PIN_CONFIG_GPIO_PIN_INT
  pinctrl: qcom: spmi-gpio: fix gpio-hog related boot issues
  sock: Reset dst when changing sk_mark via setsockopt
  net: bcmgenet: return correct value 'ret' from bcmgenet_power_down
  ACPICA: Use %d for signed int print formatting instead of %u
  dlm: don't leak kernel pointer to userspace
  dlm: fix invalid free
  scsi: lpfc: fcoe: Fix link down issue after 1000+ link bounces
  scsi: megaraid_sas: Fix msleep granularity
  scsi: mpt3sas: Fix driver modifying persistent data in Manufacturing page11
  scsi: mpt3sas: Fix Sync cache command failure during driver unload
  rtlwifi: rtl8192de: Fix misleading REG_MCUFWDL information
  wireless: airo: potential buffer overflow in sprintf()
  brcmsmac: never log "tid x is not agg'able" by default
  rtl8xxxu: Fix missing break in switch
  wlcore: Fix the return value in case of error in 'wlcore_vendor_cmd_smart_config_start()'
  audit: print empty EXECVE args
  sched/fair: Don't increase sd->balance_interval on newidle balance
  net: do not abort bulk send on BQL status
  ocfs2: fix clusters leak in ocfs2_defrag_extent()
  ocfs2: don't put and assigning null to bh allocated outside
  arm64: makefile fix build of .i file in external module case
  ntb: intel: fix return value for ndev_vec_mask()
  ntb_netdev: fix sleep time mismatch
  igb: shorten maximum PHC timecounter update interval
  mm/memory_hotplug: make add_memory() take the device_hotplug_lock
  fs/hfs/extent.c: fix array out of bounds read of array extent
  hfs: update timestamp on truncate()
  hfsplus: update timestamps on truncate()
  hfs: fix return value of hfs_get_block()
  hfsplus: fix return value of hfsplus_get_block()
  hfs: prevent btree data loss on ENOSPC
  hfsplus: prevent btree data loss on ENOSPC
  hfs: fix BUG on bnode parent update
  hfsplus: fix BUG on bnode parent update
  linux/bitmap.h: fix type of nbits in bitmap_shift_right()
  linux/bitmap.h: handle constant zero-size bitmaps correctly
  um: Make line/tty semantics use true write IRQ
  macsec: let the administrator set UP state even if lowerdev is down
  macsec: update operstate when lower device changes
  mm/page-writeback.c: fix range_cyclic writeback vs writepages deadlock
  fs/ocfs2/dlm/dlmdebug.c: fix a sleep-in-atomic-context bug in dlm_print_one_mle()
  sparc64: Rework xchg() definition to avoid warnings.
  powerpc/process: Fix flush_all_to_thread for SPE
  thermal: rcar_thermal: Prevent hardware access during system suspend
  selftests/ftrace: Fix to test kprobe $comm arg only if available
  mfd: max8997: Enale irq-wakeup unconditionally
  mfd: mc13xxx-core: Fix PMIC shutdown when reading ADC values
  mfd: arizona: Correct calling of runtime_put_sync
  net: ethernet: ti: cpsw: unsync mcast entries while switch promisc mode
  qlcnic: fix a return in qlcnic_dcb_get_capability()
  mISDN: Fix type of switch control variable in ctrl_teimanager
  f2fs: fix to spread clear_cold_data()
  rtc: s35390a: Change buf's type to u8 in s35390a_init
  ceph: fix dentry leak in ceph_readdir_prepopulate
  sparc: Fix parport build warnings.
  spi: omap2-mcspi: Set FIFO DMA trigger level to word length
  s390/perf: Return error when debug_register fails
  atm: zatm: Fix empty body Clang warnings
  sunrpc: safely reallow resvport min/max inversion
  SUNRPC: Fix a compile warning for cmpxchg64()
  usbip: tools: fix atoi() on non-null terminated string
  USB: misc: appledisplay: fix backlight update_status return code
  macintosh/windfarm_smu_sat: Fix debug output
  ALSA: i2c/cs8427: Fix int to char conversion
  kprobes, x86/ptrace.h: Make regs_get_kernel_stack_nth() not fault on bad stack
  xfs: fix use-after-free race in xfs_buf_rele
  net: ena: Fix Kconfig dependency on X86
  net: fix warning in af_unix
  scsi: dc395x: fix DMA API usage in sg_update_list
  scsi: dc395x: fix dma API usage in srb_done
  ASoC: tegra_sgtl5000: fix device_node refcounting
  clk: mmp2: fix the clock id for sdh2_clk and sdh3_clk
  scsi: iscsi_tcp: Explicitly cast param in iscsi_sw_tcp_host_get_param
  scsi: isci: Change sci_controller_start_task's return type to sci_status
  scsi: isci: Use proper enumerated type in atapi_d2h_reg_frame_handler
  KVM/x86: Fix invvpid and invept register operand size in 64-bit mode
  scsi: ips: fix missing break in switch
  amiflop: clean up on errors during setup
  m68k: fix command-line parsing when passed from u-boot
  misc: mic: fix a DMA pool free failure
  gsmi: Fix bug in append_to_eventlog sysfs handler
  btrfs: handle error of get_old_root
  mmc: mediatek: fix cannot receive new request when msdc_cmd_is_ready fail
  spi: sh-msiof: fix deferred probing
  ath10k: allocate small size dma memory in ath10k_pci_diag_write_mem
  brcmsmac: AP mode: update beacon when TIM changes
  powerpc/eeh: Fix use of EEH_PE_KEEP on wrong field
  powerpc: Fix signedness bug in update_flash_db()
  synclink_gt(): fix compat_ioctl()
  gfs2: Fix marking bitmaps non-full
  printk: fix integer overflow in setup_log_buf()
  ALSA: isight: fix leak of reference to firewire unit in error path of .probe callback
  mwifiex: Fix NL80211_TX_POWER_LIMITED
  platform/x86: asus-wmi: Only Tell EC the OS will handle display hotkeys from asus_nb_wmi
  platform/x86: asus-nb-wmi: Support ALS on the Zenbook UX430UQ
  mm/ksm.c: don't WARN if page is still mapped in remove_stable_node()
  Revert "fs: ocfs2: fix possible null-pointer dereferences in ocfs2_xa_prepare_entry()"
  tools: gpio: Correctly add make dependencies for gpio_utils
  gpio: max77620: Fixup debounce delays
  net/sched: act_pedit: fix WARN() in the traffic path
  net/mlx5e: Fix set vf link state error flow
  sfc: Only cancel the PPS workqueue if it exists
  net: rtnetlink: prevent underflows in do_setvfinfo()
  net/mlx4_en: fix mlx4 ethtool -N insertion

  Conflicts:
	drivers/pinctrl/qcom/pinctrl-spmi-gpio.c

Change-Id: I4e2fd2f605dd8552250db79ae7976dbac8223a96
Signed-off-by: jianzhou <jianzhou@codeaurora.org>
* refs/heads/tmp-a36b501:
  Linux 4.9.205
  Revert "sock: Reset dst when changing sk_mark via setsockopt"

Change-Id: I9f528492407d75abd5586f8ee57984a15c05fb43
Signed-off-by: jianzhou <jianzhou@codeaurora.org>
negrroo pushed a commit that referenced this pull request Mar 24, 2020
[ Upstream commit 6c5d911249290f41f7b50b43344a7520605b1acb ]

journal_head::b_transaction and journal_head::b_next_transaction could
be accessed concurrently as noticed by KCSAN,

 LTP: starting fsync04
 /dev/zero: Can't open blockdev
 EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem
 EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: (null)
 ==================================================================
 BUG: KCSAN: data-race in __jbd2_journal_refile_buffer [jbd2] / jbd2_write_access_granted [jbd2]

 write to 0xffff99f9b1bd0e30 of 8 bytes by task 25721 on cpu 70:
  __jbd2_journal_refile_buffer+0xdd/0x210 [jbd2]
  __jbd2_journal_refile_buffer at fs/jbd2/transaction.c:2569
  jbd2_journal_commit_transaction+0x2d15/0x3f20 [jbd2]
  (inlined by) jbd2_journal_commit_transaction at fs/jbd2/commit.c:1034
  kjournald2+0x13b/0x450 [jbd2]
  kthread+0x1cd/0x1f0
  ret_from_fork+0x27/0x50

 read to 0xffff99f9b1bd0e30 of 8 bytes by task 25724 on cpu 68:
  jbd2_write_access_granted+0x1b2/0x250 [jbd2]
  jbd2_write_access_granted at fs/jbd2/transaction.c:1155
  jbd2_journal_get_write_access+0x2c/0x60 [jbd2]
  __ext4_journal_get_write_access+0x50/0x90 [ext4]
  ext4_mb_mark_diskspace_used+0x158/0x620 [ext4]
  ext4_mb_new_blocks+0x54f/0xca0 [ext4]
  ext4_ind_map_blocks+0xc79/0x1b40 [ext4]
  ext4_map_blocks+0x3b4/0x950 [ext4]
  _ext4_get_block+0xfc/0x270 [ext4]
  ext4_get_block+0x3b/0x50 [ext4]
  __block_write_begin_int+0x22e/0xae0
  __block_write_begin+0x39/0x50
  ext4_write_begin+0x388/0xb50 [ext4]
  generic_perform_write+0x15d/0x290
  ext4_buffered_write_iter+0x11f/0x210 [ext4]
  ext4_file_write_iter+0xce/0x9e0 [ext4]
  new_sync_write+0x29c/0x3b0
  __vfs_write+0x92/0xa0
  vfs_write+0x103/0x260
  ksys_write+0x9d/0x130
  __x64_sys_write+0x4c/0x60
  do_syscall_64+0x91/0xb05
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 5 locks held by fsync04/25724:
  #0: ffff99f9911093f8 (sb_writers#13){.+.+}, at: vfs_write+0x21c/0x260
  #1: ffff99f9db4c0348 (&sb->s_type->i_mutex_key#15){+.+.}, at: ext4_buffered_write_iter+0x65/0x210 [ext4]
  #2: ffff99f5e7dfcf58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2]
  #3: ffff99f9db4c0168 (&ei->i_data_sem){++++}, at: ext4_map_blocks+0x176/0x950 [ext4]
  #4: ffffffff99086b40 (rcu_read_lock){....}, at: jbd2_write_access_granted+0x4e/0x250 [jbd2]
 irq event stamp: 1407125
 hardirqs last  enabled at (1407125): [<ffffffff980da9b7>] __find_get_block+0x107/0x790
 hardirqs last disabled at (1407124): [<ffffffff980da8f9>] __find_get_block+0x49/0x790
 softirqs last  enabled at (1405528): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c
 softirqs last disabled at (1405521): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 68 PID: 25724 Comm: fsync04 Tainted: G L 5.6.0-rc2-next-20200221+ #7
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

The plain reads are outside of jh->b_state_lock critical section which result
in data races. Fix them by adding pairs of READ|WRITE_ONCE().

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Qian Cai <cai@lca.pw>
Link: https://lore.kernel.org/r/20200222043111.2227-1-cai@lca.pw
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
negrroo pushed a commit that referenced this pull request Apr 5, 2020
…event

commit 7d36665a5886c27ca4c4d0afd3ecc50b400f3587 upstream.

An eventfd monitors multiple memory thresholds of the cgroup, closes them,
the kernel deletes all events related to this eventfd.  Before all events
are deleted, another eventfd monitors the memory threshold of this cgroup,
leading to a crash:

  BUG: kernel NULL pointer dereference, address: 0000000000000004
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 800000033058e067 P4D 800000033058e067 PUD 3355ce067 PMD 0
  Oops: 0002 [#1] SMP PTI
  CPU: 2 PID: 14012 Comm: kworker/2:6 Kdump: loaded Not tainted 5.6.0-rc4 #3
  Hardware name: LENOVO 20AWS01K00/20AWS01K00, BIOS GLET70WW (2.24 ) 05/21/2014
  Workqueue: events memcg_event_remove
  RIP: 0010:__mem_cgroup_usage_unregister_event+0xb3/0x190
  RSP: 0018:ffffb47e01c4fe18 EFLAGS: 00010202
  RAX: 0000000000000001 RBX: ffff8bb223a8a000 RCX: 0000000000000001
  RDX: 0000000000000001 RSI: ffff8bb22fb83540 RDI: 0000000000000001
  RBP: ffffb47e01c4fe48 R08: 0000000000000000 R09: 0000000000000010
  R10: 000000000000000c R11: 071c71c71c71c71c R12: ffff8bb226aba880
  R13: ffff8bb223a8a480 R14: 0000000000000000 R15: 0000000000000000
  FS:  0000000000000000(0000) GS:ffff8bb242680000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000004 CR3: 000000032c29c003 CR4: 00000000001606e0
  Call Trace:
    memcg_event_remove+0x32/0x90
    process_one_work+0x172/0x380
    worker_thread+0x49/0x3f0
    kthread+0xf8/0x130
    ret_from_fork+0x35/0x40
  CR2: 0000000000000004

We can reproduce this problem in the following ways:

1. We create a new cgroup subdirectory and a new eventfd, and then we
   monitor multiple memory thresholds of the cgroup through this eventfd.

2.  closing this eventfd, and __mem_cgroup_usage_unregister_event ()
   will be called multiple times to delete all events related to this
   eventfd.

The first time __mem_cgroup_usage_unregister_event() is called, the
kernel will clear all items related to this eventfd in thresholds->
primary.

Since there is currently only one eventfd, thresholds-> primary becomes
empty, so the kernel will set thresholds-> primary and hresholds-> spare
to NULL.  If at this time, the user creates a new eventfd and monitor
the memory threshold of this cgroup, kernel will re-initialize
thresholds-> primary.

Then when __mem_cgroup_usage_unregister_event () is called for the
second time, because thresholds-> primary is not empty, the system will
access thresholds-> spare, but thresholds-> spare is NULL, which will
trigger a crash.

In general, the longer it takes to delete all events related to this
eventfd, the easier it is to trigger this problem.

The solution is to check whether the thresholds associated with the
eventfd has been cleared when deleting the event.  If so, we do nothing.

[akpm@linux-foundation.org: fix comment, per Kirill]
Fixes: 907860e ("cgroups: make cftype.unregister_event() void-returning")
Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/077a6f67-aefa-4591-efec-f2f3af2b0b02@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
negrroo pushed a commit that referenced this pull request Apr 5, 2020
commit 9765635b30756eb74e05e260ac812659c296cd28 upstream.

This reverts commit:

c54c7374ff44 ("drm/dp_mst: Skip validating ports during destruction, just ref")

ugh.

In drm_dp_destroy_connector_work(), we have a pretty good chance of
freeing the actual struct drm_dp_mst_port. However, after destroying
things we send a hotplug through (*mgr->cbs->hotplug)(mgr) which is
where the problems start.

For i915, this calls all the way down to the fbcon probing helpers,
which start trying to access the port in a modeset.

[   45.062001] ==================================================================
[   45.062112] BUG: KASAN: use-after-free in ex_handler_refcount+0x146/0x180
[   45.062196] Write of size 4 at addr ffff8882b4b70968 by task kworker/3:1/53

[   45.062325] CPU: 3 PID: 53 Comm: kworker/3:1 Kdump: loaded Tainted: G           O      4.20.0-rc4Lyude-Test+ #3
[   45.062442] Hardware name: LENOVO 20BWS1KY00/20BWS1KY00, BIOS JBET71WW (1.35 ) 09/14/2018
[   45.062554] Workqueue: events drm_dp_destroy_connector_work [drm_kms_helper]
[   45.062641] Call Trace:
[   45.062685]  dump_stack+0xbd/0x15a
[   45.062735]  ? dump_stack_print_info.cold.0+0x1b/0x1b
[   45.062801]  ? printk+0x9f/0xc5
[   45.062847]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   45.062909]  ? ex_handler_refcount+0x146/0x180
[   45.062970]  print_address_description+0x71/0x239
[   45.063036]  ? ex_handler_refcount+0x146/0x180
[   45.063095]  kasan_report.cold.5+0x242/0x30b
[   45.063155]  __asan_report_store4_noabort+0x1c/0x20
[   45.063313]  ex_handler_refcount+0x146/0x180
[   45.063371]  ? ex_handler_clear_fs+0xb0/0xb0
[   45.063428]  fixup_exception+0x98/0xd7
[   45.063484]  ? raw_notifier_call_chain+0x20/0x20
[   45.063548]  do_trap+0x6d/0x210
[   45.063605]  ? _GLOBAL__sub_I_65535_1_drm_dp_aux_unregister_devnode+0x2f/0x1c6 [drm_kms_helper]
[   45.063732]  do_error_trap+0xc0/0x170
[   45.063802]  ? _GLOBAL__sub_I_65535_1_drm_dp_aux_unregister_devnode+0x2f/0x1c6 [drm_kms_helper]
[   45.063929]  do_invalid_op+0x3b/0x50
[   45.063997]  ? _GLOBAL__sub_I_65535_1_drm_dp_aux_unregister_devnode+0x2f/0x1c6 [drm_kms_helper]
[   45.064103]  invalid_op+0x14/0x20
[   45.064162] RIP: 0010:_GLOBAL__sub_I_65535_1_drm_dp_aux_unregister_devnode+0x2f/0x1c6 [drm_kms_helper]
[   45.064274] Code: 00 48 c7 c7 80 fe 53 a0 48 89 e5 e8 5b 6f 26 e1 5d c3 48 8d 0e 0f 0b 48 8d 0b 0f 0b 48 8d 0f 0f 0b 48 8d 0f 0f 0b 49 8d 4d 00 <0f> 0b 49 8d 0e 0f 0b 48 8d 08 0f 0b 49 8d 4d 00 0f 0b 48 8d 0b 0f
[   45.064569] RSP: 0018:ffff8882b789ee10 EFLAGS: 00010282
[   45.064637] RAX: ffff8882af47ae70 RBX: ffff8882af47aa60 RCX: ffff8882b4b70968
[   45.064723] RDX: ffff8882af47ae70 RSI: 0000000000000008 RDI: ffff8882b788bdb8
[   45.064808] RBP: ffff8882b789ee28 R08: ffffed1056f13db4 R09: ffffed1056f13db3
[   45.064894] R10: ffffed1056f13db3 R11: ffff8882b789ed9f R12: ffff8882af47ad28
[   45.064980] R13: ffff8882b4b70968 R14: ffff8882acd86728 R15: ffff8882b4b75dc8
[   45.065084]  drm_dp_mst_reset_vcpi_slots+0x12/0x80 [drm_kms_helper]
[   45.065225]  intel_mst_disable_dp+0xda/0x180 [i915]
[   45.065361]  intel_encoders_disable.isra.107+0x197/0x310 [i915]
[   45.065498]  haswell_crtc_disable+0xbe/0x400 [i915]
[   45.065622]  ? i9xx_disable_plane+0x1c0/0x3e0 [i915]
[   45.065750]  intel_atomic_commit_tail+0x74e/0x3e60 [i915]
[   45.065884]  ? intel_pre_plane_update+0xbc0/0xbc0 [i915]
[   45.065968]  ? drm_atomic_helper_swap_state+0x88b/0x1d90 [drm_kms_helper]
[   45.066054]  ? kasan_check_write+0x14/0x20
[   45.066165]  ? i915_gem_track_fb+0x13a/0x330 [i915]
[   45.066277]  ? i915_sw_fence_complete+0xe9/0x140 [i915]
[   45.066406]  ? __i915_sw_fence_complete+0xc50/0xc50 [i915]
[   45.066540]  intel_atomic_commit+0x72e/0xef0 [i915]
[   45.066635]  ? drm_dev_dbg+0x200/0x200 [drm]
[   45.066764]  ? intel_atomic_commit_tail+0x3e60/0x3e60 [i915]
[   45.066898]  ? intel_atomic_commit_tail+0x3e60/0x3e60 [i915]
[   45.067001]  drm_atomic_commit+0xc4/0xf0 [drm]
[   45.067074]  restore_fbdev_mode_atomic+0x562/0x780 [drm_kms_helper]
[   45.067166]  ? drm_fb_helper_debug_leave+0x690/0x690 [drm_kms_helper]
[   45.067249]  ? kasan_check_read+0x11/0x20
[   45.067324]  restore_fbdev_mode+0x127/0x4b0 [drm_kms_helper]
[   45.067364]  ? kasan_check_read+0x11/0x20
[   45.067406]  drm_fb_helper_restore_fbdev_mode_unlocked+0x164/0x200 [drm_kms_helper]
[   45.067462]  ? drm_fb_helper_hotplug_event+0x30/0x30 [drm_kms_helper]
[   45.067508]  ? kasan_check_write+0x14/0x20
[   45.070360]  ? mutex_unlock+0x22/0x40
[   45.073748]  drm_fb_helper_set_par+0xb2/0xf0 [drm_kms_helper]
[   45.075846]  drm_fb_helper_hotplug_event.part.33+0x1cd/0x290 [drm_kms_helper]
[   45.078088]  drm_fb_helper_hotplug_event+0x1c/0x30 [drm_kms_helper]
[   45.082614]  intel_fbdev_output_poll_changed+0x9f/0x140 [i915]
[   45.087069]  drm_kms_helper_hotplug_event+0x67/0x90 [drm_kms_helper]
[   45.089319]  intel_dp_mst_hotplug+0x37/0x50 [i915]
[   45.091496]  drm_dp_destroy_connector_work+0x510/0x6f0 [drm_kms_helper]
[   45.093675]  ? drm_dp_update_payload_part1+0x1220/0x1220 [drm_kms_helper]
[   45.095851]  ? kasan_check_write+0x14/0x20
[   45.098473]  ? kasan_check_read+0x11/0x20
[   45.101155]  ? strscpy+0x17c/0x530
[   45.103808]  ? __switch_to_asm+0x34/0x70
[   45.106456]  ? syscall_return_via_sysret+0xf/0x7f
[   45.109711]  ? read_word_at_a_time+0x20/0x20
[   45.113138]  ? __switch_to_asm+0x40/0x70
[   45.116529]  ? __switch_to_asm+0x34/0x70
[   45.119891]  ? __switch_to_asm+0x40/0x70
[   45.123224]  ? __switch_to_asm+0x34/0x70
[   45.126540]  ? __switch_to_asm+0x34/0x70
[   45.129824]  process_one_work+0x88d/0x15d0
[   45.133172]  ? pool_mayday_timeout+0x850/0x850
[   45.136459]  ? pci_mmcfg_check_reserved+0x110/0x128
[   45.139739]  ? wake_q_add+0xb0/0xb0
[   45.143010]  ? check_preempt_wakeup+0x652/0x1050
[   45.146304]  ? worker_enter_idle+0x29e/0x740
[   45.149589]  ? __schedule+0x1ec0/0x1ec0
[   45.152937]  ? kasan_check_read+0x11/0x20
[   45.156179]  ? _raw_spin_lock_irq+0xa3/0x130
[   45.159382]  ? _raw_read_unlock_irqrestore+0x30/0x30
[   45.162542]  ? kasan_check_write+0x14/0x20
[   45.165657]  worker_thread+0x1a5/0x1470
[   45.168725]  ? set_load_weight+0x2e0/0x2e0
[   45.171755]  ? process_one_work+0x15d0/0x15d0
[   45.174806]  ? __switch_to_asm+0x34/0x70
[   45.177645]  ? __switch_to_asm+0x40/0x70
[   45.180323]  ? __switch_to_asm+0x34/0x70
[   45.182936]  ? __switch_to_asm+0x40/0x70
[   45.185539]  ? __switch_to_asm+0x34/0x70
[   45.188100]  ? __switch_to_asm+0x40/0x70
[   45.190628]  ? __schedule+0x7d4/0x1ec0
[   45.193143]  ? save_stack+0xa9/0xd0
[   45.195632]  ? kasan_check_write+0x10/0x20
[   45.198162]  ? kasan_kmalloc+0xc4/0xe0
[   45.200609]  ? kmem_cache_alloc_trace+0xdd/0x190
[   45.203046]  ? kthread+0x9f/0x3b0
[   45.205470]  ? ret_from_fork+0x35/0x40
[   45.207876]  ? unwind_next_frame+0x43/0x50
[   45.210273]  ? __save_stack_trace+0x82/0x100
[   45.212658]  ? deactivate_slab.isra.67+0x3d4/0x580
[   45.215026]  ? default_wake_function+0x35/0x50
[   45.217399]  ? kasan_check_read+0x11/0x20
[   45.219825]  ? _raw_spin_lock_irqsave+0xae/0x140
[   45.222174]  ? __lock_text_start+0x8/0x8
[   45.224521]  ? replenish_dl_entity.cold.62+0x4f/0x4f
[   45.226868]  ? __kthread_parkme+0x87/0xf0
[   45.229200]  kthread+0x2f7/0x3b0
[   45.231557]  ? process_one_work+0x15d0/0x15d0
[   45.233923]  ? kthread_park+0x120/0x120
[   45.236249]  ret_from_fork+0x35/0x40

[   45.240875] Allocated by task 242:
[   45.243136]  save_stack+0x43/0xd0
[   45.245385]  kasan_kmalloc+0xc4/0xe0
[   45.247597]  kmem_cache_alloc_trace+0xdd/0x190
[   45.249793]  drm_dp_add_port+0x1e0/0x2170 [drm_kms_helper]
[   45.252000]  drm_dp_send_link_address+0x4a7/0x740 [drm_kms_helper]
[   45.254389]  drm_dp_check_and_send_link_address+0x1a7/0x210 [drm_kms_helper]
[   45.256803]  drm_dp_mst_link_probe_work+0x6f/0xb0 [drm_kms_helper]
[   45.259200]  process_one_work+0x88d/0x15d0
[   45.261597]  worker_thread+0x1a5/0x1470
[   45.264038]  kthread+0x2f7/0x3b0
[   45.266371]  ret_from_fork+0x35/0x40

[   45.270937] Freed by task 53:
[   45.273170]  save_stack+0x43/0xd0
[   45.275382]  __kasan_slab_free+0x139/0x190
[   45.277604]  kasan_slab_free+0xe/0x10
[   45.279826]  kfree+0x99/0x1b0
[   45.282044]  drm_dp_free_mst_port+0x4a/0x60 [drm_kms_helper]
[   45.284330]  drm_dp_destroy_connector_work+0x43e/0x6f0 [drm_kms_helper]
[   45.286660]  process_one_work+0x88d/0x15d0
[   45.288934]  worker_thread+0x1a5/0x1470
[   45.291231]  kthread+0x2f7/0x3b0
[   45.293547]  ret_from_fork+0x35/0x40

[   45.298206] The buggy address belongs to the object at ffff8882b4b70968
                which belongs to the cache kmalloc-2k of size 2048
[   45.303047] The buggy address is located 0 bytes inside of
                2048-byte region [ffff8882b4b70968, ffff8882b4b71168)
[   45.308010] The buggy address belongs to the page:
[   45.310477] page:ffffea000ad2dc00 count:1 mapcount:0 mapping:ffff8882c080cf40 index:0x0 compound_mapcount: 0
[   45.313051] flags: 0x8000000000010200(slab|head)
[   45.315635] raw: 8000000000010200 ffffea000aac2808 ffffea000abe8608 ffff8882c080cf40
[   45.318300] raw: 0000000000000000 00000000000d000d 00000001ffffffff 0000000000000000
[   45.320966] page dumped because: kasan: bad access detected

[   45.326312] Memory state around the buggy address:
[   45.329085]  ffff8882b4b70800: fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   45.331845]  ffff8882b4b70880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   45.334584] >ffff8882b4b70900: fc fc fc fc fc fc fc fc fc fc fc fc fc fb fb fb
[   45.337302]                                                           ^
[   45.340061]  ffff8882b4b70980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   45.342910]  ffff8882b4b70a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   45.345748] ==================================================================

So, this definitely isn't a fix that we want. This being said; there's
no real easy fix for this problem because of some of the catch-22's of
the MST helpers current design. For starters; we always need to validate
a port with drm_dp_get_validated_port_ref(), but validation relies on
the lifetime of the port in the actual topology. So once the port is
gone, it can't be validated again.

If we were to try to make the payload helpers not use port validation,
then we'd cause another problem: if the port isn't validated, it could
be freed and we'd just start causing more KASAN issues. There are
already hacks that attempt to workaround this in
drm_dp_mst_destroy_connector_work() by re-initializing the kref so that
it can be used again and it's memory can be freed once the VCPI helpers
finish removing the port's respective payloads. But none of these really
do anything helpful since the port still can't be validated since it's
gone from the topology. Also, that workaround is immensely confusing to
read through.

What really needs to be done in order to fix this is to teach DRM how to
track the lifetime of the structs for MST ports and branch devices
separately from their lifetime in the actual topology. Simply put; this
means having two different krefs-one that removes the port/branch device
from the topology, and one that finally calls kfree(). This would let us
simplify things, since we'd now be able to keep ports around without
having to keep them in the topology at the same time, which is exactly
what we need in order to teach our VCPI helpers to only validate ports
when it's actually necessary without running the risk of trying to use
unallocated memory.

Such a fix is on it's way, but for now let's play it safe and just
revert this. If this bug has been around for well over a year, we can
wait a little while to get an actual proper fix here.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Fixes: c54c7374ff44 ("drm/dp_mst: Skip validating ports during destruction, just ref")
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sean Paul <sean@poorly.run>
Cc: Jerry Zuo <Jerry.Zuo@amd.com>
Cc: Harry Wentland <Harry.Wentland@amd.com>
Cc: stable@vger.kernel.org # v4.6+
Acked-by: Sean Paul <sean@poorly.run>
Link: https://patchwork.freedesktop.org/patch/msgid/20181128210005.24434-1-lyude@redhat.com
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
negrroo pushed a commit that referenced this pull request Apr 27, 2020
commit 28936b62e71e41600bab319f262ea9f9b1027629 upstream.

inode->i_blocks could be accessed concurrently as noticed by KCSAN,

 BUG: KCSAN: data-race in ext4_do_update_inode [ext4] / inode_add_bytes

 write to 0xffff9a00d4b982d0 of 8 bytes by task 22100 on cpu 118:
  inode_add_bytes+0x65/0xf0
  __inode_add_bytes at fs/stat.c:689
  (inlined by) inode_add_bytes at fs/stat.c:702
  ext4_mb_new_blocks+0x418/0xca0 [ext4]
  ext4_ext_map_blocks+0x1a6b/0x27b0 [ext4]
  ext4_map_blocks+0x1a9/0x950 [ext4]
  _ext4_get_block+0xfc/0x270 [ext4]
  ext4_get_block_unwritten+0x33/0x50 [ext4]
  __block_write_begin_int+0x22e/0xae0
  __block_write_begin+0x39/0x50
  ext4_write_begin+0x388/0xb50 [ext4]
  ext4_da_write_begin+0x35f/0x8f0 [ext4]
  generic_perform_write+0x15d/0x290
  ext4_buffered_write_iter+0x11f/0x210 [ext4]
  ext4_file_write_iter+0xce/0x9e0 [ext4]
  new_sync_write+0x29c/0x3b0
  __vfs_write+0x92/0xa0
  vfs_write+0x103/0x260
  ksys_write+0x9d/0x130
  __x64_sys_write+0x4c/0x60
  do_syscall_64+0x91/0xb05
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 read to 0xffff9a00d4b982d0 of 8 bytes by task 8 on cpu 65:
  ext4_do_update_inode+0x4a0/0xf60 [ext4]
  ext4_inode_blocks_set at fs/ext4/inode.c:4815
  ext4_mark_iloc_dirty+0xaf/0x160 [ext4]
  ext4_mark_inode_dirty+0x129/0x3e0 [ext4]
  ext4_convert_unwritten_extents+0x253/0x2d0 [ext4]
  ext4_convert_unwritten_io_end_vec+0xc5/0x150 [ext4]
  ext4_end_io_rsv_work+0x22c/0x350 [ext4]
  process_one_work+0x54f/0xb90
  worker_thread+0x80/0x5f0
  kthread+0x1cd/0x1f0
  ret_from_fork+0x27/0x50

 4 locks held by kworker/u256:0/8:
  #0: ffff9a025abc4328 ((wq_completion)ext4-rsv-conversion){+.+.}, at: process_one_work+0x443/0xb90
  #1: ffffab5a862dbe20 ((work_completion)(&ei->i_rsv_conversion_work)){+.+.}, at: process_one_work+0x443/0xb90
  #2: ffff9a025a9d0f58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2]
  #3: ffff9a00d4b985d8 (&(&ei->i_raw_lock)->rlock){+.+.}, at: ext4_do_update_inode+0xaa/0xf60 [ext4]
 irq event stamp: 3009267
 hardirqs last  enabled at (3009267): [<ffffffff980da9b7>] __find_get_block+0x107/0x790
 hardirqs last disabled at (3009266): [<ffffffff980da8f9>] __find_get_block+0x49/0x790
 softirqs last  enabled at (3009230): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c
 softirqs last disabled at (3009223): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 65 PID: 8 Comm: kworker/u256:0 Tainted: G L 5.6.0-rc2-next-20200221+ #7
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019
 Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work [ext4]

The plain read is outside of inode->i_lock critical section which
results in a data race. Fix it by adding READ_ONCE() there.

Link: https://lore.kernel.org/r/20200222043258.2279-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
negrroo pushed a commit that referenced this pull request May 7, 2020
commit 5cbf3264bc715e9eb384e2b68601f8c02bb9a61d upstream.

Use follow_pfn() to get the PFN of a PFNMAP VMA instead of assuming that
vma->vm_pgoff holds the base PFN of the VMA.  This fixes a bug where
attempting to do VFIO_IOMMU_MAP_DMA on an arbitrary PFNMAP'd region of
memory calculates garbage for the PFN.

Hilariously, this only got detected because the first "PFN" calculated
by vaddr_get_pfn() is PFN 0 (vma->vm_pgoff==0), and iommu_iova_to_phys()
uses PA==0 as an error, which triggers a WARN in vfio_unmap_unpin()
because the translation "failed".  PFN 0 is now unconditionally reserved
on x86 in order to mitigate L1TF, which causes is_invalid_reserved_pfn()
to return true and in turns results in vaddr_get_pfn() returning success
for PFN 0.  Eventually the bogus calculation runs into PFNs that aren't
reserved and leads to failure in vfio_pin_map_dma().  The subsequent
call to vfio_remove_dma() attempts to unmap PFN 0 and WARNs.

  WARNING: CPU: 8 PID: 5130 at drivers/vfio/vfio_iommu_type1.c:750 vfio_unmap_unpin+0x2e1/0x310 [vfio_iommu_type1]
  Modules linked in: vfio_pci vfio_virqfd vfio_iommu_type1 vfio ...
  CPU: 8 PID: 5130 Comm: sgx Tainted: G        W         5.6.0-rc5-705d787c7fee-vfio+ #3
  Hardware name: Intel Corporation Mehlow UP Server Platform/Moss Beach Server, BIOS CNLSE2R1.D00.X119.B49.1803010910 03/01/2018
  RIP: 0010:vfio_unmap_unpin+0x2e1/0x310 [vfio_iommu_type1]
  Code: <0f> 0b 49 81 c5 00 10 00 00 e9 c5 fe ff ff bb 00 10 00 00 e9 3d fe
  RSP: 0018:ffffbeb5039ebda8 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff9a55cbf8d480 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff9a52b771c200
  RBP: 0000000000000000 R08: 0000000000000040 R09: 00000000fffffff2
  R10: 0000000000000001 R11: ffff9a51fa896000 R12: 0000000184010000
  R13: 0000000184000000 R14: 0000000000010000 R15: ffff9a55cb66ea08
  FS:  00007f15d3830b40(0000) GS:ffff9a55d5600000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000561cf39429e0 CR3: 000000084f75f005 CR4: 00000000003626e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   vfio_remove_dma+0x17/0x70 [vfio_iommu_type1]
   vfio_iommu_type1_ioctl+0x9e3/0xa7b [vfio_iommu_type1]
   ksys_ioctl+0x92/0xb0
   __x64_sys_ioctl+0x16/0x20
   do_syscall_64+0x4c/0x180
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7f15d04c75d7
  Code: <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 81 48 2d 00 f7 d8 64 89 01 48

Fixes: 73fa0d1 ("vfio: Type1 IOMMU implementation")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
negrroo pushed a commit that referenced this pull request May 22, 2020
[ Upstream commit 76e752701a8af4404bbd9c45723f7cbd6e4a251e ]

Some servers seem to accept connections while booting but never send
the SMBNegotiate response neither close the connection, causing all
processes accessing the share hang on uninterruptible sleep state.

This happens when the cifs_demultiplex_thread detects the server is
unresponsive so releases the socket and start trying to reconnect.
At some point, the faulty server will accept the socket and the TCP
status will be set to NeedNegotiate. The first issued command accessing
the share will start the negotiation (pid 5828 below), but the response
will never arrive so other commands will be blocked waiting on the mutex
(pid 55352).

This patch checks for unresponsive servers also on the negotiate stage
releasing the socket and reconnecting if the response is not received
and checking again the tcp state when the mutex is acquired.

PID: 55352  TASK: ffff880fd6cc02c0  CPU: 0   COMMAND: "ls"
 #0 [ffff880fd9add9f0] schedule at ffffffff81467eb9
 #1 [ffff880fd9addb38] __mutex_lock_slowpath at ffffffff81468fe0
 #2 [ffff880fd9addba8] mutex_lock at ffffffff81468b1a
 #3 [ffff880fd9addbc0] cifs_reconnect_tcon at ffffffffa042f905 [cifs]
 #4 [ffff880fd9addc60] smb_init at ffffffffa042faeb [cifs]
 #5 [ffff880fd9addca0] CIFSSMBQPathInfo at ffffffffa04360b5 [cifs]
 ....

Which is waiting a mutex owned by:

PID: 5828   TASK: ffff880fcc55e400  CPU: 0   COMMAND: "xxxx"
 #0 [ffff880fbfdc19b8] schedule at ffffffff81467eb9
 #1 [ffff880fbfdc1b00] wait_for_response at ffffffffa044f96d [cifs]
 #2 [ffff880fbfdc1b60] SendReceive at ffffffffa04505ce [cifs]
 #3 [ffff880fbfdc1bb0] CIFSSMBNegotiate at ffffffffa0438d79 [cifs]
 #4 [ffff880fbfdc1c50] cifs_negotiate_protocol at ffffffffa043b383 [cifs]
 #5 [ffff880fbfdc1c80] cifs_reconnect_tcon at ffffffffa042f911 [cifs]
 #6 [ffff880fbfdc1d20] smb_init at ffffffffa042faeb [cifs]
 #7 [ffff880fbfdc1d60] CIFSSMBQFSInfo at ffffffffa0434eb0 [cifs]
 ....

Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Aurélien Aptel <aaptel@suse.de>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
@negrroo negrroo force-pushed the master branch 2 times, most recently from bbbd7bc to 3e3f2fc Compare July 16, 2020 12:00
negrroo pushed a commit that referenced this pull request Jul 16, 2020
[ Upstream commit 42ffb0bf584ae5b6b38f72259af1e0ee417ac77f]

There exists a deadlock with range_cyclic that has existed forever.  If
we loop around with a bio already built we could deadlock with a writer
who has the page locked that we're attempting to write but is waiting on
a page in our bio to be written out.  The task traces are as follows

  PID: 1329874  TASK: ffff889ebcdf3800  CPU: 33  COMMAND: "kworker/u113:5"
   #0 [ffffc900297bb658] __schedule at ffffffff81a4c33f
   #1 [ffffc900297bb6e0] schedule at ffffffff81a4c6e3
   #2 [ffffc900297bb6f8] io_schedule at ffffffff81a4ca42
   #3 [ffffc900297bb708] __lock_page at ffffffff811f145b
   #4 [ffffc900297bb798] __process_pages_contig at ffffffff814bc502
   #5 [ffffc900297bb8c8] lock_delalloc_pages at ffffffff814bc684
   #6 [ffffc900297bb900] find_lock_delalloc_range at ffffffff814be9ff
   #7 [ffffc900297bb9a0] writepage_delalloc at ffffffff814bebd0
   #8 [ffffc900297bba18] __extent_writepage at ffffffff814bfbf2
   #9 [ffffc900297bba98] extent_write_cache_pages at ffffffff814bffbd

  PID: 2167901  TASK: ffff889dc6a59c00  CPU: 14  COMMAND:
  "aio-dio-invalid"
   #0 [ffffc9003b50bb18] __schedule at ffffffff81a4c33f
   #1 [ffffc9003b50bba0] schedule at ffffffff81a4c6e3
   #2 [ffffc9003b50bbb8] io_schedule at ffffffff81a4ca42
   #3 [ffffc9003b50bbc8] wait_on_page_bit at ffffffff811f24d6
   #4 [ffffc9003b50bc60] prepare_pages at ffffffff814b05a7
   #5 [ffffc9003b50bcd8] btrfs_buffered_write at ffffffff814b1359
   #6 [ffffc9003b50bdb0] btrfs_file_write_iter at ffffffff814b5933
   #7 [ffffc9003b50be38] new_sync_write at ffffffff8128f6a8
   #8 [ffffc9003b50bec8] vfs_write at ffffffff81292b9d
   #9 [ffffc9003b50bf00] ksys_pwrite64 at ffffffff81293032

I used drgn to find the respective pages we were stuck on

page_entry.page 0xffffea00fbfc7500 index 8148 bit 15 pid 2167901
page_entry.page 0xffffea00f9bb7400 index 7680 bit 0 pid 1329874

As you can see the kworker is waiting for bit 0 (PG_locked) on index
7680, and aio-dio-invalid is waiting for bit 15 (PG_writeback) on index
8148.  aio-dio-invalid has 7680, and the kworker epd looks like the
following

  crash> struct extent_page_data ffffc900297bbbb0
  struct extent_page_data {
    bio = 0xffff889f747ed830,
    tree = 0xffff889eed6ba448,
    extent_locked = 0,
    sync_io = 0
  }

Probably worth mentioning as well that it waits for writeback of the
page to complete while holding a lock on it (at prepare_pages()).

Using drgn I walked the bio pages looking for page
0xffffea00fbfc7500 which is the one we're waiting for writeback on

  bio = Object(prog, 'struct bio', address=0xffff889f747ed830)
  for i in range(0, bio.bi_vcnt.value_()):
      bv = bio.bi_io_vec[i]
      if bv.bv_page.value_() == 0xffffea00fbfc7500:
	  print("FOUND IT")

which validated what I suspected.

The fix for this is simple, flush the epd before we loop back around to
the beginning of the file during writeout.

Fixes: b293f02 ("Btrfs: Add writepages support")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
negrroo pushed a commit that referenced this pull request Jul 16, 2020
[ Upstream commit 6c5d911249290f41f7b50b43344a7520605b1acb ]

journal_head::b_transaction and journal_head::b_next_transaction could
be accessed concurrently as noticed by KCSAN,

 LTP: starting fsync04
 /dev/zero: Can't open blockdev
 EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem
 EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: (null)
 ==================================================================
 BUG: KCSAN: data-race in __jbd2_journal_refile_buffer [jbd2] / jbd2_write_access_granted [jbd2]

 write to 0xffff99f9b1bd0e30 of 8 bytes by task 25721 on cpu 70:
  __jbd2_journal_refile_buffer+0xdd/0x210 [jbd2]
  __jbd2_journal_refile_buffer at fs/jbd2/transaction.c:2569
  jbd2_journal_commit_transaction+0x2d15/0x3f20 [jbd2]
  (inlined by) jbd2_journal_commit_transaction at fs/jbd2/commit.c:1034
  kjournald2+0x13b/0x450 [jbd2]
  kthread+0x1cd/0x1f0
  ret_from_fork+0x27/0x50

 read to 0xffff99f9b1bd0e30 of 8 bytes by task 25724 on cpu 68:
  jbd2_write_access_granted+0x1b2/0x250 [jbd2]
  jbd2_write_access_granted at fs/jbd2/transaction.c:1155
  jbd2_journal_get_write_access+0x2c/0x60 [jbd2]
  __ext4_journal_get_write_access+0x50/0x90 [ext4]
  ext4_mb_mark_diskspace_used+0x158/0x620 [ext4]
  ext4_mb_new_blocks+0x54f/0xca0 [ext4]
  ext4_ind_map_blocks+0xc79/0x1b40 [ext4]
  ext4_map_blocks+0x3b4/0x950 [ext4]
  _ext4_get_block+0xfc/0x270 [ext4]
  ext4_get_block+0x3b/0x50 [ext4]
  __block_write_begin_int+0x22e/0xae0
  __block_write_begin+0x39/0x50
  ext4_write_begin+0x388/0xb50 [ext4]
  generic_perform_write+0x15d/0x290
  ext4_buffered_write_iter+0x11f/0x210 [ext4]
  ext4_file_write_iter+0xce/0x9e0 [ext4]
  new_sync_write+0x29c/0x3b0
  __vfs_write+0x92/0xa0
  vfs_write+0x103/0x260
  ksys_write+0x9d/0x130
  __x64_sys_write+0x4c/0x60
  do_syscall_64+0x91/0xb05
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 5 locks held by fsync04/25724:
  #0: ffff99f9911093f8 (sb_writers#13){.+.+}, at: vfs_write+0x21c/0x260
  #1: ffff99f9db4c0348 (&sb->s_type->i_mutex_key#15){+.+.}, at: ext4_buffered_write_iter+0x65/0x210 [ext4]
  #2: ffff99f5e7dfcf58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2]
  #3: ffff99f9db4c0168 (&ei->i_data_sem){++++}, at: ext4_map_blocks+0x176/0x950 [ext4]
  #4: ffffffff99086b40 (rcu_read_lock){....}, at: jbd2_write_access_granted+0x4e/0x250 [jbd2]
 irq event stamp: 1407125
 hardirqs last  enabled at (1407125): [<ffffffff980da9b7>] __find_get_block+0x107/0x790
 hardirqs last disabled at (1407124): [<ffffffff980da8f9>] __find_get_block+0x49/0x790
 softirqs last  enabled at (1405528): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c
 softirqs last disabled at (1405521): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 68 PID: 25724 Comm: fsync04 Tainted: G L 5.6.0-rc2-next-20200221+ #7
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

The plain reads are outside of jh->b_state_lock critical section which result
in data races. Fix them by adding pairs of READ|WRITE_ONCE().

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Qian Cai <cai@lca.pw>
Link: https://lore.kernel.org/r/20200222043111.2227-1-cai@lca.pw
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
negrroo pushed a commit that referenced this pull request Jul 16, 2020
…event

commit 7d36665a5886c27ca4c4d0afd3ecc50b400f3587 upstream.

An eventfd monitors multiple memory thresholds of the cgroup, closes them,
the kernel deletes all events related to this eventfd.  Before all events
are deleted, another eventfd monitors the memory threshold of this cgroup,
leading to a crash:

  BUG: kernel NULL pointer dereference, address: 0000000000000004
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 800000033058e067 P4D 800000033058e067 PUD 3355ce067 PMD 0
  Oops: 0002 [#1] SMP PTI
  CPU: 2 PID: 14012 Comm: kworker/2:6 Kdump: loaded Not tainted 5.6.0-rc4 #3
  Hardware name: LENOVO 20AWS01K00/20AWS01K00, BIOS GLET70WW (2.24 ) 05/21/2014
  Workqueue: events memcg_event_remove
  RIP: 0010:__mem_cgroup_usage_unregister_event+0xb3/0x190
  RSP: 0018:ffffb47e01c4fe18 EFLAGS: 00010202
  RAX: 0000000000000001 RBX: ffff8bb223a8a000 RCX: 0000000000000001
  RDX: 0000000000000001 RSI: ffff8bb22fb83540 RDI: 0000000000000001
  RBP: ffffb47e01c4fe48 R08: 0000000000000000 R09: 0000000000000010
  R10: 000000000000000c R11: 071c71c71c71c71c R12: ffff8bb226aba880
  R13: ffff8bb223a8a480 R14: 0000000000000000 R15: 0000000000000000
  FS:  0000000000000000(0000) GS:ffff8bb242680000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000004 CR3: 000000032c29c003 CR4: 00000000001606e0
  Call Trace:
    memcg_event_remove+0x32/0x90
    process_one_work+0x172/0x380
    worker_thread+0x49/0x3f0
    kthread+0xf8/0x130
    ret_from_fork+0x35/0x40
  CR2: 0000000000000004

We can reproduce this problem in the following ways:

1. We create a new cgroup subdirectory and a new eventfd, and then we
   monitor multiple memory thresholds of the cgroup through this eventfd.

2.  closing this eventfd, and __mem_cgroup_usage_unregister_event ()
   will be called multiple times to delete all events related to this
   eventfd.

The first time __mem_cgroup_usage_unregister_event() is called, the
kernel will clear all items related to this eventfd in thresholds->
primary.

Since there is currently only one eventfd, thresholds-> primary becomes
empty, so the kernel will set thresholds-> primary and hresholds-> spare
to NULL.  If at this time, the user creates a new eventfd and monitor
the memory threshold of this cgroup, kernel will re-initialize
thresholds-> primary.

Then when __mem_cgroup_usage_unregister_event () is called for the
second time, because thresholds-> primary is not empty, the system will
access thresholds-> spare, but thresholds-> spare is NULL, which will
trigger a crash.

In general, the longer it takes to delete all events related to this
eventfd, the easier it is to trigger this problem.

The solution is to check whether the thresholds associated with the
eventfd has been cleared when deleting the event.  If so, we do nothing.

[akpm@linux-foundation.org: fix comment, per Kirill]
Fixes: 907860e ("cgroups: make cftype.unregister_event() void-returning")
Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/077a6f67-aefa-4591-efec-f2f3af2b0b02@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
negrroo pushed a commit that referenced this pull request Jul 16, 2020
commit 9765635b30756eb74e05e260ac812659c296cd28 upstream.

This reverts commit:

c54c7374ff44 ("drm/dp_mst: Skip validating ports during destruction, just ref")

ugh.

In drm_dp_destroy_connector_work(), we have a pretty good chance of
freeing the actual struct drm_dp_mst_port. However, after destroying
things we send a hotplug through (*mgr->cbs->hotplug)(mgr) which is
where the problems start.

For i915, this calls all the way down to the fbcon probing helpers,
which start trying to access the port in a modeset.

[   45.062001] ==================================================================
[   45.062112] BUG: KASAN: use-after-free in ex_handler_refcount+0x146/0x180
[   45.062196] Write of size 4 at addr ffff8882b4b70968 by task kworker/3:1/53

[   45.062325] CPU: 3 PID: 53 Comm: kworker/3:1 Kdump: loaded Tainted: G           O      4.20.0-rc4Lyude-Test+ #3
[   45.062442] Hardware name: LENOVO 20BWS1KY00/20BWS1KY00, BIOS JBET71WW (1.35 ) 09/14/2018
[   45.062554] Workqueue: events drm_dp_destroy_connector_work [drm_kms_helper]
[   45.062641] Call Trace:
[   45.062685]  dump_stack+0xbd/0x15a
[   45.062735]  ? dump_stack_print_info.cold.0+0x1b/0x1b
[   45.062801]  ? printk+0x9f/0xc5
[   45.062847]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   45.062909]  ? ex_handler_refcount+0x146/0x180
[   45.062970]  print_address_description+0x71/0x239
[   45.063036]  ? ex_handler_refcount+0x146/0x180
[   45.063095]  kasan_report.cold.5+0x242/0x30b
[   45.063155]  __asan_report_store4_noabort+0x1c/0x20
[   45.063313]  ex_handler_refcount+0x146/0x180
[   45.063371]  ? ex_handler_clear_fs+0xb0/0xb0
[   45.063428]  fixup_exception+0x98/0xd7
[   45.063484]  ? raw_notifier_call_chain+0x20/0x20
[   45.063548]  do_trap+0x6d/0x210
[   45.063605]  ? _GLOBAL__sub_I_65535_1_drm_dp_aux_unregister_devnode+0x2f/0x1c6 [drm_kms_helper]
[   45.063732]  do_error_trap+0xc0/0x170
[   45.063802]  ? _GLOBAL__sub_I_65535_1_drm_dp_aux_unregister_devnode+0x2f/0x1c6 [drm_kms_helper]
[   45.063929]  do_invalid_op+0x3b/0x50
[   45.063997]  ? _GLOBAL__sub_I_65535_1_drm_dp_aux_unregister_devnode+0x2f/0x1c6 [drm_kms_helper]
[   45.064103]  invalid_op+0x14/0x20
[   45.064162] RIP: 0010:_GLOBAL__sub_I_65535_1_drm_dp_aux_unregister_devnode+0x2f/0x1c6 [drm_kms_helper]
[   45.064274] Code: 00 48 c7 c7 80 fe 53 a0 48 89 e5 e8 5b 6f 26 e1 5d c3 48 8d 0e 0f 0b 48 8d 0b 0f 0b 48 8d 0f 0f 0b 48 8d 0f 0f 0b 49 8d 4d 00 <0f> 0b 49 8d 0e 0f 0b 48 8d 08 0f 0b 49 8d 4d 00 0f 0b 48 8d 0b 0f
[   45.064569] RSP: 0018:ffff8882b789ee10 EFLAGS: 00010282
[   45.064637] RAX: ffff8882af47ae70 RBX: ffff8882af47aa60 RCX: ffff8882b4b70968
[   45.064723] RDX: ffff8882af47ae70 RSI: 0000000000000008 RDI: ffff8882b788bdb8
[   45.064808] RBP: ffff8882b789ee28 R08: ffffed1056f13db4 R09: ffffed1056f13db3
[   45.064894] R10: ffffed1056f13db3 R11: ffff8882b789ed9f R12: ffff8882af47ad28
[   45.064980] R13: ffff8882b4b70968 R14: ffff8882acd86728 R15: ffff8882b4b75dc8
[   45.065084]  drm_dp_mst_reset_vcpi_slots+0x12/0x80 [drm_kms_helper]
[   45.065225]  intel_mst_disable_dp+0xda/0x180 [i915]
[   45.065361]  intel_encoders_disable.isra.107+0x197/0x310 [i915]
[   45.065498]  haswell_crtc_disable+0xbe/0x400 [i915]
[   45.065622]  ? i9xx_disable_plane+0x1c0/0x3e0 [i915]
[   45.065750]  intel_atomic_commit_tail+0x74e/0x3e60 [i915]
[   45.065884]  ? intel_pre_plane_update+0xbc0/0xbc0 [i915]
[   45.065968]  ? drm_atomic_helper_swap_state+0x88b/0x1d90 [drm_kms_helper]
[   45.066054]  ? kasan_check_write+0x14/0x20
[   45.066165]  ? i915_gem_track_fb+0x13a/0x330 [i915]
[   45.066277]  ? i915_sw_fence_complete+0xe9/0x140 [i915]
[   45.066406]  ? __i915_sw_fence_complete+0xc50/0xc50 [i915]
[   45.066540]  intel_atomic_commit+0x72e/0xef0 [i915]
[   45.066635]  ? drm_dev_dbg+0x200/0x200 [drm]
[   45.066764]  ? intel_atomic_commit_tail+0x3e60/0x3e60 [i915]
[   45.066898]  ? intel_atomic_commit_tail+0x3e60/0x3e60 [i915]
[   45.067001]  drm_atomic_commit+0xc4/0xf0 [drm]
[   45.067074]  restore_fbdev_mode_atomic+0x562/0x780 [drm_kms_helper]
[   45.067166]  ? drm_fb_helper_debug_leave+0x690/0x690 [drm_kms_helper]
[   45.067249]  ? kasan_check_read+0x11/0x20
[   45.067324]  restore_fbdev_mode+0x127/0x4b0 [drm_kms_helper]
[   45.067364]  ? kasan_check_read+0x11/0x20
[   45.067406]  drm_fb_helper_restore_fbdev_mode_unlocked+0x164/0x200 [drm_kms_helper]
[   45.067462]  ? drm_fb_helper_hotplug_event+0x30/0x30 [drm_kms_helper]
[   45.067508]  ? kasan_check_write+0x14/0x20
[   45.070360]  ? mutex_unlock+0x22/0x40
[   45.073748]  drm_fb_helper_set_par+0xb2/0xf0 [drm_kms_helper]
[   45.075846]  drm_fb_helper_hotplug_event.part.33+0x1cd/0x290 [drm_kms_helper]
[   45.078088]  drm_fb_helper_hotplug_event+0x1c/0x30 [drm_kms_helper]
[   45.082614]  intel_fbdev_output_poll_changed+0x9f/0x140 [i915]
[   45.087069]  drm_kms_helper_hotplug_event+0x67/0x90 [drm_kms_helper]
[   45.089319]  intel_dp_mst_hotplug+0x37/0x50 [i915]
[   45.091496]  drm_dp_destroy_connector_work+0x510/0x6f0 [drm_kms_helper]
[   45.093675]  ? drm_dp_update_payload_part1+0x1220/0x1220 [drm_kms_helper]
[   45.095851]  ? kasan_check_write+0x14/0x20
[   45.098473]  ? kasan_check_read+0x11/0x20
[   45.101155]  ? strscpy+0x17c/0x530
[   45.103808]  ? __switch_to_asm+0x34/0x70
[   45.106456]  ? syscall_return_via_sysret+0xf/0x7f
[   45.109711]  ? read_word_at_a_time+0x20/0x20
[   45.113138]  ? __switch_to_asm+0x40/0x70
[   45.116529]  ? __switch_to_asm+0x34/0x70
[   45.119891]  ? __switch_to_asm+0x40/0x70
[   45.123224]  ? __switch_to_asm+0x34/0x70
[   45.126540]  ? __switch_to_asm+0x34/0x70
[   45.129824]  process_one_work+0x88d/0x15d0
[   45.133172]  ? pool_mayday_timeout+0x850/0x850
[   45.136459]  ? pci_mmcfg_check_reserved+0x110/0x128
[   45.139739]  ? wake_q_add+0xb0/0xb0
[   45.143010]  ? check_preempt_wakeup+0x652/0x1050
[   45.146304]  ? worker_enter_idle+0x29e/0x740
[   45.149589]  ? __schedule+0x1ec0/0x1ec0
[   45.152937]  ? kasan_check_read+0x11/0x20
[   45.156179]  ? _raw_spin_lock_irq+0xa3/0x130
[   45.159382]  ? _raw_read_unlock_irqrestore+0x30/0x30
[   45.162542]  ? kasan_check_write+0x14/0x20
[   45.165657]  worker_thread+0x1a5/0x1470
[   45.168725]  ? set_load_weight+0x2e0/0x2e0
[   45.171755]  ? process_one_work+0x15d0/0x15d0
[   45.174806]  ? __switch_to_asm+0x34/0x70
[   45.177645]  ? __switch_to_asm+0x40/0x70
[   45.180323]  ? __switch_to_asm+0x34/0x70
[   45.182936]  ? __switch_to_asm+0x40/0x70
[   45.185539]  ? __switch_to_asm+0x34/0x70
[   45.188100]  ? __switch_to_asm+0x40/0x70
[   45.190628]  ? __schedule+0x7d4/0x1ec0
[   45.193143]  ? save_stack+0xa9/0xd0
[   45.195632]  ? kasan_check_write+0x10/0x20
[   45.198162]  ? kasan_kmalloc+0xc4/0xe0
[   45.200609]  ? kmem_cache_alloc_trace+0xdd/0x190
[   45.203046]  ? kthread+0x9f/0x3b0
[   45.205470]  ? ret_from_fork+0x35/0x40
[   45.207876]  ? unwind_next_frame+0x43/0x50
[   45.210273]  ? __save_stack_trace+0x82/0x100
[   45.212658]  ? deactivate_slab.isra.67+0x3d4/0x580
[   45.215026]  ? default_wake_function+0x35/0x50
[   45.217399]  ? kasan_check_read+0x11/0x20
[   45.219825]  ? _raw_spin_lock_irqsave+0xae/0x140
[   45.222174]  ? __lock_text_start+0x8/0x8
[   45.224521]  ? replenish_dl_entity.cold.62+0x4f/0x4f
[   45.226868]  ? __kthread_parkme+0x87/0xf0
[   45.229200]  kthread+0x2f7/0x3b0
[   45.231557]  ? process_one_work+0x15d0/0x15d0
[   45.233923]  ? kthread_park+0x120/0x120
[   45.236249]  ret_from_fork+0x35/0x40

[   45.240875] Allocated by task 242:
[   45.243136]  save_stack+0x43/0xd0
[   45.245385]  kasan_kmalloc+0xc4/0xe0
[   45.247597]  kmem_cache_alloc_trace+0xdd/0x190
[   45.249793]  drm_dp_add_port+0x1e0/0x2170 [drm_kms_helper]
[   45.252000]  drm_dp_send_link_address+0x4a7/0x740 [drm_kms_helper]
[   45.254389]  drm_dp_check_and_send_link_address+0x1a7/0x210 [drm_kms_helper]
[   45.256803]  drm_dp_mst_link_probe_work+0x6f/0xb0 [drm_kms_helper]
[   45.259200]  process_one_work+0x88d/0x15d0
[   45.261597]  worker_thread+0x1a5/0x1470
[   45.264038]  kthread+0x2f7/0x3b0
[   45.266371]  ret_from_fork+0x35/0x40

[   45.270937] Freed by task 53:
[   45.273170]  save_stack+0x43/0xd0
[   45.275382]  __kasan_slab_free+0x139/0x190
[   45.277604]  kasan_slab_free+0xe/0x10
[   45.279826]  kfree+0x99/0x1b0
[   45.282044]  drm_dp_free_mst_port+0x4a/0x60 [drm_kms_helper]
[   45.284330]  drm_dp_destroy_connector_work+0x43e/0x6f0 [drm_kms_helper]
[   45.286660]  process_one_work+0x88d/0x15d0
[   45.288934]  worker_thread+0x1a5/0x1470
[   45.291231]  kthread+0x2f7/0x3b0
[   45.293547]  ret_from_fork+0x35/0x40

[   45.298206] The buggy address belongs to the object at ffff8882b4b70968
                which belongs to the cache kmalloc-2k of size 2048
[   45.303047] The buggy address is located 0 bytes inside of
                2048-byte region [ffff8882b4b70968, ffff8882b4b71168)
[   45.308010] The buggy address belongs to the page:
[   45.310477] page:ffffea000ad2dc00 count:1 mapcount:0 mapping:ffff8882c080cf40 index:0x0 compound_mapcount: 0
[   45.313051] flags: 0x8000000000010200(slab|head)
[   45.315635] raw: 8000000000010200 ffffea000aac2808 ffffea000abe8608 ffff8882c080cf40
[   45.318300] raw: 0000000000000000 00000000000d000d 00000001ffffffff 0000000000000000
[   45.320966] page dumped because: kasan: bad access detected

[   45.326312] Memory state around the buggy address:
[   45.329085]  ffff8882b4b70800: fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   45.331845]  ffff8882b4b70880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   45.334584] >ffff8882b4b70900: fc fc fc fc fc fc fc fc fc fc fc fc fc fb fb fb
[   45.337302]                                                           ^
[   45.340061]  ffff8882b4b70980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   45.342910]  ffff8882b4b70a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   45.345748] ==================================================================

So, this definitely isn't a fix that we want. This being said; there's
no real easy fix for this problem because of some of the catch-22's of
the MST helpers current design. For starters; we always need to validate
a port with drm_dp_get_validated_port_ref(), but validation relies on
the lifetime of the port in the actual topology. So once the port is
gone, it can't be validated again.

If we were to try to make the payload helpers not use port validation,
then we'd cause another problem: if the port isn't validated, it could
be freed and we'd just start causing more KASAN issues. There are
already hacks that attempt to workaround this in
drm_dp_mst_destroy_connector_work() by re-initializing the kref so that
it can be used again and it's memory can be freed once the VCPI helpers
finish removing the port's respective payloads. But none of these really
do anything helpful since the port still can't be validated since it's
gone from the topology. Also, that workaround is immensely confusing to
read through.

What really needs to be done in order to fix this is to teach DRM how to
track the lifetime of the structs for MST ports and branch devices
separately from their lifetime in the actual topology. Simply put; this
means having two different krefs-one that removes the port/branch device
from the topology, and one that finally calls kfree(). This would let us
simplify things, since we'd now be able to keep ports around without
having to keep them in the topology at the same time, which is exactly
what we need in order to teach our VCPI helpers to only validate ports
when it's actually necessary without running the risk of trying to use
unallocated memory.

Such a fix is on it's way, but for now let's play it safe and just
revert this. If this bug has been around for well over a year, we can
wait a little while to get an actual proper fix here.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Fixes: c54c7374ff44 ("drm/dp_mst: Skip validating ports during destruction, just ref")
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sean Paul <sean@poorly.run>
Cc: Jerry Zuo <Jerry.Zuo@amd.com>
Cc: Harry Wentland <Harry.Wentland@amd.com>
Cc: stable@vger.kernel.org # v4.6+
Acked-by: Sean Paul <sean@poorly.run>
Link: https://patchwork.freedesktop.org/patch/msgid/20181128210005.24434-1-lyude@redhat.com
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
negrroo pushed a commit that referenced this pull request Jul 16, 2020
commit 28936b62e71e41600bab319f262ea9f9b1027629 upstream.

inode->i_blocks could be accessed concurrently as noticed by KCSAN,

 BUG: KCSAN: data-race in ext4_do_update_inode [ext4] / inode_add_bytes

 write to 0xffff9a00d4b982d0 of 8 bytes by task 22100 on cpu 118:
  inode_add_bytes+0x65/0xf0
  __inode_add_bytes at fs/stat.c:689
  (inlined by) inode_add_bytes at fs/stat.c:702
  ext4_mb_new_blocks+0x418/0xca0 [ext4]
  ext4_ext_map_blocks+0x1a6b/0x27b0 [ext4]
  ext4_map_blocks+0x1a9/0x950 [ext4]
  _ext4_get_block+0xfc/0x270 [ext4]
  ext4_get_block_unwritten+0x33/0x50 [ext4]
  __block_write_begin_int+0x22e/0xae0
  __block_write_begin+0x39/0x50
  ext4_write_begin+0x388/0xb50 [ext4]
  ext4_da_write_begin+0x35f/0x8f0 [ext4]
  generic_perform_write+0x15d/0x290
  ext4_buffered_write_iter+0x11f/0x210 [ext4]
  ext4_file_write_iter+0xce/0x9e0 [ext4]
  new_sync_write+0x29c/0x3b0
  __vfs_write+0x92/0xa0
  vfs_write+0x103/0x260
  ksys_write+0x9d/0x130
  __x64_sys_write+0x4c/0x60
  do_syscall_64+0x91/0xb05
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 read to 0xffff9a00d4b982d0 of 8 bytes by task 8 on cpu 65:
  ext4_do_update_inode+0x4a0/0xf60 [ext4]
  ext4_inode_blocks_set at fs/ext4/inode.c:4815
  ext4_mark_iloc_dirty+0xaf/0x160 [ext4]
  ext4_mark_inode_dirty+0x129/0x3e0 [ext4]
  ext4_convert_unwritten_extents+0x253/0x2d0 [ext4]
  ext4_convert_unwritten_io_end_vec+0xc5/0x150 [ext4]
  ext4_end_io_rsv_work+0x22c/0x350 [ext4]
  process_one_work+0x54f/0xb90
  worker_thread+0x80/0x5f0
  kthread+0x1cd/0x1f0
  ret_from_fork+0x27/0x50

 4 locks held by kworker/u256:0/8:
  #0: ffff9a025abc4328 ((wq_completion)ext4-rsv-conversion){+.+.}, at: process_one_work+0x443/0xb90
  #1: ffffab5a862dbe20 ((work_completion)(&ei->i_rsv_conversion_work)){+.+.}, at: process_one_work+0x443/0xb90
  #2: ffff9a025a9d0f58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2]
  #3: ffff9a00d4b985d8 (&(&ei->i_raw_lock)->rlock){+.+.}, at: ext4_do_update_inode+0xaa/0xf60 [ext4]
 irq event stamp: 3009267
 hardirqs last  enabled at (3009267): [<ffffffff980da9b7>] __find_get_block+0x107/0x790
 hardirqs last disabled at (3009266): [<ffffffff980da8f9>] __find_get_block+0x49/0x790
 softirqs last  enabled at (3009230): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c
 softirqs last disabled at (3009223): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 65 PID: 8 Comm: kworker/u256:0 Tainted: G L 5.6.0-rc2-next-20200221+ #7
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019
 Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work [ext4]

The plain read is outside of inode->i_lock critical section which
results in a data race. Fix it by adding READ_ONCE() there.

Link: https://lore.kernel.org/r/20200222043258.2279-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
negrroo pushed a commit that referenced this pull request Jul 16, 2020
commit 5cbf3264bc715e9eb384e2b68601f8c02bb9a61d upstream.

Use follow_pfn() to get the PFN of a PFNMAP VMA instead of assuming that
vma->vm_pgoff holds the base PFN of the VMA.  This fixes a bug where
attempting to do VFIO_IOMMU_MAP_DMA on an arbitrary PFNMAP'd region of
memory calculates garbage for the PFN.

Hilariously, this only got detected because the first "PFN" calculated
by vaddr_get_pfn() is PFN 0 (vma->vm_pgoff==0), and iommu_iova_to_phys()
uses PA==0 as an error, which triggers a WARN in vfio_unmap_unpin()
because the translation "failed".  PFN 0 is now unconditionally reserved
on x86 in order to mitigate L1TF, which causes is_invalid_reserved_pfn()
to return true and in turns results in vaddr_get_pfn() returning success
for PFN 0.  Eventually the bogus calculation runs into PFNs that aren't
reserved and leads to failure in vfio_pin_map_dma().  The subsequent
call to vfio_remove_dma() attempts to unmap PFN 0 and WARNs.

  WARNING: CPU: 8 PID: 5130 at drivers/vfio/vfio_iommu_type1.c:750 vfio_unmap_unpin+0x2e1/0x310 [vfio_iommu_type1]
  Modules linked in: vfio_pci vfio_virqfd vfio_iommu_type1 vfio ...
  CPU: 8 PID: 5130 Comm: sgx Tainted: G        W         5.6.0-rc5-705d787c7fee-vfio+ #3
  Hardware name: Intel Corporation Mehlow UP Server Platform/Moss Beach Server, BIOS CNLSE2R1.D00.X119.B49.1803010910 03/01/2018
  RIP: 0010:vfio_unmap_unpin+0x2e1/0x310 [vfio_iommu_type1]
  Code: <0f> 0b 49 81 c5 00 10 00 00 e9 c5 fe ff ff bb 00 10 00 00 e9 3d fe
  RSP: 0018:ffffbeb5039ebda8 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff9a55cbf8d480 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff9a52b771c200
  RBP: 0000000000000000 R08: 0000000000000040 R09: 00000000fffffff2
  R10: 0000000000000001 R11: ffff9a51fa896000 R12: 0000000184010000
  R13: 0000000184000000 R14: 0000000000010000 R15: ffff9a55cb66ea08
  FS:  00007f15d3830b40(0000) GS:ffff9a55d5600000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000561cf39429e0 CR3: 000000084f75f005 CR4: 00000000003626e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   vfio_remove_dma+0x17/0x70 [vfio_iommu_type1]
   vfio_iommu_type1_ioctl+0x9e3/0xa7b [vfio_iommu_type1]
   ksys_ioctl+0x92/0xb0
   __x64_sys_ioctl+0x16/0x20
   do_syscall_64+0x4c/0x180
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7f15d04c75d7
  Code: <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 81 48 2d 00 f7 d8 64 89 01 48

Fixes: 73fa0d1 ("vfio: Type1 IOMMU implementation")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
negrroo pushed a commit that referenced this pull request Jul 16, 2020
[ Upstream commit 76e752701a8af4404bbd9c45723f7cbd6e4a251e ]

Some servers seem to accept connections while booting but never send
the SMBNegotiate response neither close the connection, causing all
processes accessing the share hang on uninterruptible sleep state.

This happens when the cifs_demultiplex_thread detects the server is
unresponsive so releases the socket and start trying to reconnect.
At some point, the faulty server will accept the socket and the TCP
status will be set to NeedNegotiate. The first issued command accessing
the share will start the negotiation (pid 5828 below), but the response
will never arrive so other commands will be blocked waiting on the mutex
(pid 55352).

This patch checks for unresponsive servers also on the negotiate stage
releasing the socket and reconnecting if the response is not received
and checking again the tcp state when the mutex is acquired.

PID: 55352  TASK: ffff880fd6cc02c0  CPU: 0   COMMAND: "ls"
 #0 [ffff880fd9add9f0] schedule at ffffffff81467eb9
 #1 [ffff880fd9addb38] __mutex_lock_slowpath at ffffffff81468fe0
 #2 [ffff880fd9addba8] mutex_lock at ffffffff81468b1a
 #3 [ffff880fd9addbc0] cifs_reconnect_tcon at ffffffffa042f905 [cifs]
 #4 [ffff880fd9addc60] smb_init at ffffffffa042faeb [cifs]
 #5 [ffff880fd9addca0] CIFSSMBQPathInfo at ffffffffa04360b5 [cifs]
 ....

Which is waiting a mutex owned by:

PID: 5828   TASK: ffff880fcc55e400  CPU: 0   COMMAND: "xxxx"
 #0 [ffff880fbfdc19b8] schedule at ffffffff81467eb9
 #1 [ffff880fbfdc1b00] wait_for_response at ffffffffa044f96d [cifs]
 #2 [ffff880fbfdc1b60] SendReceive at ffffffffa04505ce [cifs]
 #3 [ffff880fbfdc1bb0] CIFSSMBNegotiate at ffffffffa0438d79 [cifs]
 #4 [ffff880fbfdc1c50] cifs_negotiate_protocol at ffffffffa043b383 [cifs]
 #5 [ffff880fbfdc1c80] cifs_reconnect_tcon at ffffffffa042f911 [cifs]
 #6 [ffff880fbfdc1d20] smb_init at ffffffffa042faeb [cifs]
 #7 [ffff880fbfdc1d60] CIFSSMBQFSInfo at ffffffffa0434eb0 [cifs]
 ....

Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Aurélien Aptel <aaptel@suse.de>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
negrroo pushed a commit that referenced this pull request Jul 16, 2020
[ Upstream commit f6766ff6afff70e2aaf39e1511e16d471de7c3ae ]

We need to check mddev->del_work before flush workqueu since the purpose
of flush is to ensure the previous md is disappeared. Otherwise the similar
deadlock appeared if LOCKDEP is enabled, it is due to md_open holds the
bdev->bd_mutex before flush workqueue.

kernel: [  154.522645] ======================================================
kernel: [  154.522647] WARNING: possible circular locking dependency detected
kernel: [  154.522650] 5.6.0-rc7-lp151.27-default #25 Tainted: G           O
kernel: [  154.522651] ------------------------------------------------------
kernel: [  154.522653] mdadm/2482 is trying to acquire lock:
kernel: [  154.522655] ffff888078529128 ((wq_completion)md_misc){+.+.}, at: flush_workqueue+0x84/0x4b0
kernel: [  154.522673]
kernel: [  154.522673] but task is already holding lock:
kernel: [  154.522675] ffff88804efa9338 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x79/0x590
kernel: [  154.522691]
kernel: [  154.522691] which lock already depends on the new lock.
kernel: [  154.522691]
kernel: [  154.522694]
kernel: [  154.522694] the existing dependency chain (in reverse order) is:
kernel: [  154.522696]
kernel: [  154.522696] -> #4 (&bdev->bd_mutex){+.+.}:
kernel: [  154.522704]        __mutex_lock+0x87/0x950
kernel: [  154.522706]        __blkdev_get+0x79/0x590
kernel: [  154.522708]        blkdev_get+0x65/0x140
kernel: [  154.522709]        blkdev_get_by_dev+0x2f/0x40
kernel: [  154.522716]        lock_rdev+0x3d/0x90 [md_mod]
kernel: [  154.522719]        md_import_device+0xd6/0x1b0 [md_mod]
kernel: [  154.522723]        new_dev_store+0x15e/0x210 [md_mod]
kernel: [  154.522728]        md_attr_store+0x7a/0xc0 [md_mod]
kernel: [  154.522732]        kernfs_fop_write+0x117/0x1b0
kernel: [  154.522735]        vfs_write+0xad/0x1a0
kernel: [  154.522737]        ksys_write+0xa4/0xe0
kernel: [  154.522745]        do_syscall_64+0x64/0x2b0
kernel: [  154.522748]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
kernel: [  154.522749]
kernel: [  154.522749] -> #3 (&mddev->reconfig_mutex){+.+.}:
kernel: [  154.522752]        __mutex_lock+0x87/0x950
kernel: [  154.522756]        new_dev_store+0xc9/0x210 [md_mod]
kernel: [  154.522759]        md_attr_store+0x7a/0xc0 [md_mod]
kernel: [  154.522761]        kernfs_fop_write+0x117/0x1b0
kernel: [  154.522763]        vfs_write+0xad/0x1a0
kernel: [  154.522765]        ksys_write+0xa4/0xe0
kernel: [  154.522767]        do_syscall_64+0x64/0x2b0
kernel: [  154.522769]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
kernel: [  154.522770]
kernel: [  154.522770] -> #2 (kn->count#253){++++}:
kernel: [  154.522775]        __kernfs_remove+0x253/0x2c0
kernel: [  154.522778]        kernfs_remove+0x1f/0x30
kernel: [  154.522780]        kobject_del+0x28/0x60
kernel: [  154.522783]        mddev_delayed_delete+0x24/0x30 [md_mod]
kernel: [  154.522786]        process_one_work+0x2a7/0x5f0
kernel: [  154.522788]        worker_thread+0x2d/0x3d0
kernel: [  154.522793]        kthread+0x117/0x130
kernel: [  154.522795]        ret_from_fork+0x3a/0x50
kernel: [  154.522796]
kernel: [  154.522796] -> #1 ((work_completion)(&mddev->del_work)){+.+.}:
kernel: [  154.522800]        process_one_work+0x27e/0x5f0
kernel: [  154.522802]        worker_thread+0x2d/0x3d0
kernel: [  154.522804]        kthread+0x117/0x130
kernel: [  154.522806]        ret_from_fork+0x3a/0x50
kernel: [  154.522807]
kernel: [  154.522807] -> #0 ((wq_completion)md_misc){+.+.}:
kernel: [  154.522813]        __lock_acquire+0x1392/0x1690
kernel: [  154.522816]        lock_acquire+0xb4/0x1a0
kernel: [  154.522818]        flush_workqueue+0xab/0x4b0
kernel: [  154.522821]        md_open+0xb6/0xc0 [md_mod]
kernel: [  154.522823]        __blkdev_get+0xea/0x590
kernel: [  154.522825]        blkdev_get+0x65/0x140
kernel: [  154.522828]        do_dentry_open+0x1d1/0x380
kernel: [  154.522831]        path_openat+0x567/0xcc0
kernel: [  154.522834]        do_filp_open+0x9b/0x110
kernel: [  154.522836]        do_sys_openat2+0x201/0x2a0
kernel: [  154.522838]        do_sys_open+0x57/0x80
kernel: [  154.522840]        do_syscall_64+0x64/0x2b0
kernel: [  154.522842]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
kernel: [  154.522844]
kernel: [  154.522844] other info that might help us debug this:
kernel: [  154.522844]
kernel: [  154.522846] Chain exists of:
kernel: [  154.522846]   (wq_completion)md_misc --> &mddev->reconfig_mutex --> &bdev->bd_mutex
kernel: [  154.522846]
kernel: [  154.522850]  Possible unsafe locking scenario:
kernel: [  154.522850]
kernel: [  154.522852]        CPU0                    CPU1
kernel: [  154.522853]        ----                    ----
kernel: [  154.522854]   lock(&bdev->bd_mutex);
kernel: [  154.522856]                                lock(&mddev->reconfig_mutex);
kernel: [  154.522858]                                lock(&bdev->bd_mutex);
kernel: [  154.522860]   lock((wq_completion)md_misc);
kernel: [  154.522861]
kernel: [  154.522861]  *** DEADLOCK ***
kernel: [  154.522861]
kernel: [  154.522864] 1 lock held by mdadm/2482:
kernel: [  154.522865]  #0: ffff88804efa9338 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x79/0x590
kernel: [  154.522868]
kernel: [  154.522868] stack backtrace:
kernel: [  154.522873] CPU: 1 PID: 2482 Comm: mdadm Tainted: G           O      5.6.0-rc7-lp151.27-default #25
kernel: [  154.522875] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
kernel: [  154.522878] Call Trace:
kernel: [  154.522881]  dump_stack+0x8f/0xcb
kernel: [  154.522884]  check_noncircular+0x194/0x1b0
kernel: [  154.522888]  ? __lock_acquire+0x1392/0x1690
kernel: [  154.522890]  __lock_acquire+0x1392/0x1690
kernel: [  154.522893]  lock_acquire+0xb4/0x1a0
kernel: [  154.522895]  ? flush_workqueue+0x84/0x4b0
kernel: [  154.522898]  flush_workqueue+0xab/0x4b0
kernel: [  154.522900]  ? flush_workqueue+0x84/0x4b0
kernel: [  154.522905]  ? md_open+0xb6/0xc0 [md_mod]
kernel: [  154.522908]  md_open+0xb6/0xc0 [md_mod]
kernel: [  154.522910]  __blkdev_get+0xea/0x590
kernel: [  154.522912]  ? bd_acquire+0xc0/0xc0
kernel: [  154.522914]  blkdev_get+0x65/0x140
kernel: [  154.522916]  ? bd_acquire+0xc0/0xc0
kernel: [  154.522918]  do_dentry_open+0x1d1/0x380
kernel: [  154.522921]  path_openat+0x567/0xcc0
kernel: [  154.522923]  ? __lock_acquire+0x380/0x1690
kernel: [  154.522926]  do_filp_open+0x9b/0x110
kernel: [  154.522929]  ? __alloc_fd+0xe5/0x1f0
kernel: [  154.522935]  ? kmem_cache_alloc+0x28c/0x630
kernel: [  154.522939]  ? do_sys_openat2+0x201/0x2a0
kernel: [  154.522941]  do_sys_openat2+0x201/0x2a0
kernel: [  154.522944]  do_sys_open+0x57/0x80
kernel: [  154.522946]  do_syscall_64+0x64/0x2b0
kernel: [  154.522948]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
kernel: [  154.522951] RIP: 0033:0x7f98d279d9ae

And md_alloc also flushed the same workqueue, but the thing is different
here. Because all the paths call md_alloc don't hold bdev->bd_mutex, and
the flush is necessary to avoid race condition, so leave it as it is.

Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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