Fix memory leaks when using zchunk

CMakeLists.txt

@@ -9,6 +9,7 @@ OPTION (ENABLE_PYTHON "Build Python bindings" ON)
 OPTION (USE_GPGME "Use GpgMe (instead of rpm library) for OpenPGP key support" ON)
 OPTION (USE_RUN_GNUPG_USER_SOCKET "Create a directory for gpg-agent socket in /run/gnugp/user (instead of /run/user)" OFF)
 OPTION (ENABLE_SELINUX "Restore SELinux labels on GnuPG directories" ON)
+OPTION (WITH_SANITIZERS "Build with address, leak and undefined sanitizers (DEBUG ONLY)" OFF)
 
 INCLUDE (${CMAKE_SOURCE_DIR}/VERSION.cmake)
 SET (VERSION "${LIBREPO_MAJOR}.${LIBREPO_MINOR}.${LIBREPO_PATCH}")
@@ -95,6 +96,12 @@ IF (NOT CURL_FOUND)
     MESSAGE(FATAL_ERROR "No CURL library installed")
 ENDIF (NOT CURL_FOUND)
 
+IF (WITH_SANITIZERS)
+    MESSAGE(WARNING "Building with sanitizers enabled!")
+    ADD_COMPILE_OPTIONS(-fsanitize=address -fsanitize=undefined -fsanitize=leak)
+    LINK_LIBRARIES(asan ubsan)
+ENDIF()
+
 # Generate header files with the configured ABI (e.g. with/without zchunk).
 
 configure_file("librepo/downloadtarget.h.in" "librepo/downloadtarget.h" @ONLY)

librepo.spec

@@ -19,6 +19,8 @@
 # Needs to match how gnupg2 is compiled
 %bcond_with run_gnupg_user_socket
 
+%bcond_with sanitizers
+
 %if %{with use_gpgme} && %{with use_selinux}
 %global need_selinux 1
 %else
@@ -59,6 +61,12 @@ BuildRequires:  pkgconfig(zck) >= 0.9.11
 %endif
 Requires:       libcurl%{?_isa} >= %{libcurl_version}
 
+%if %{with sanitizers}
+BuildRequires:  libasan
+BuildRequires:  liblsan
+BuildRequires:  libubsan
+%endif
+
 %description
 A library providing C and Python (libcURL like) API to downloading repository
 metadata.
@@ -97,6 +105,7 @@ Python 3 bindings for the librepo library.
     -DWITH_ZCHUNK=%{?with_zchunk:ON}%{!?with_zchunk:OFF} \
     -DUSE_GPGME=%{?with_use_gpgme:ON}%{!?with_use_gpgme:OFF} \
     -DUSE_RUN_GNUPG_USER_SOCKET=%{?with_run_gnupg_user_socket:ON}%{!?with_run_gnupg_user_socket:OFF} \
+    -DWITH_SANITIZERS=%{?with_sanitizers:ON}%{!?with_sanitizers:OFF} \
 %if %{need_selinux}
     -DENABLE_SELINUX=ON
 %else

librepo/downloader.c

@@ -1139,6 +1139,8 @@ prep_zck_header(LrTarget *target, GError **err)
         zck = lr_zck_init_read(target->target, target->target->path,
                                fd, &tmp_err);
         if(zck) {
+            zckCtx *old_zck = zck_dl_get_zck(target->target->zck_dl);
+            zck_free(&old_zck);
             if(!zck_dl_set_zck(target->target->zck_dl, zck)) {
                 g_set_error(err, LR_DOWNLOADER_ERROR, LRE_ZCK,
                             "Unable to setup zchunk download context");
@@ -1228,6 +1230,7 @@ find_local_zck_chunks(LrTarget *target, GError **err)
 
             zckCtx *zck_src = zck_create();
             if(!zck_init_read(zck_src, chk_fd)) {
+                zck_free(&zck_src);
                 close(chk_fd);
                 continue;
             }
@@ -1354,8 +1357,6 @@ check_zck(LrTarget *target, GError **err)
 
         if(cks_good == 1) {  // All checksums good
             g_debug("%s: File is complete", __func__);
-            if(target->target->zck_dl)
-                zck_dl_free(&(target->target->zck_dl));
             target->zck_state = LR_ZCK_DL_FINISHED;
             return TRUE;
         }
@@ -1375,8 +1376,6 @@ check_zck(LrTarget *target, GError **err)
         }
 
         if(cks_good == 1) {  // All checksums good
-            if(target->target->zck_dl)
-                zck_dl_free(&(target->target->zck_dl));
             target->zck_state = LR_ZCK_DL_FINISHED;
             return TRUE;
         }

librepo/downloadtarget.c

@@ -134,6 +134,26 @@ lr_downloadtarget_free(LrDownloadTarget *target)
     if (!target)
         return;
 
+    #ifdef WITH_ZCHUNK
+    if (target->zck_dl) {
+        zckCtx *zck = zck_dl_get_zck(target->zck_dl);
+        if (zck) {
+            zck_free(&zck);
+        }
+
+        zckRange *range = zck_dl_get_range(target->zck_dl);
+        if(range) {
+            zck_range_free(&range);
+        }
+
+        zck_dl_free(&target->zck_dl);
+    }
+    #endif /* WITH_ZCHUNK */
+
+    if(target->range) {
+        free(target->range);
+    }
+
     g_slist_free_full(target->checksums,
                       (GDestroyNotify) lr_downloadtargetchecksum_free);
     g_string_chunk_free(target->chunk);