Fix error when rewriting an ELF with DT_RELR relocations

lief-project · Sep 14, 2024 · bf931df · bf931df
1 parent cd81ed3
commit bf931df
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Showing 3 changed files with 10 additions and 17 deletions.
diff --git a/doc/sphinx/changelog.rst b/doc/sphinx/changelog.rst
@@ -56,6 +56,8 @@ Changelog
 
 :ELF:
 
+  * Fix a critical error when rewriting ELF file with ``DT_RELR`` relocations.
+    This error leads to a crash of the modified binary.
   * Fix error while (re)generating ELF's RELR relocations (:issue:`1097`)
   * Add support for RISC-V architecture
   * Fix bug when trying to remove a dynamic symbol that is associated with

diff --git a/src/ELF/Binary.tcc b/src/ELF/Binary.tcc
@@ -44,10 +44,6 @@ void Binary::patch_relocations<ARCH::ARM>(uint64_t from, uint64_t shift) {
       relocation.address(relocation.address() + shift);
     }
 
-    if (relocation.encoding() == Relocation::ENCODING::RELR) {
-      continue;
-    }
-
     const Relocation::TYPE type = relocation.type();
 
     switch (type) {
@@ -82,10 +78,6 @@ void Binary::patch_relocations<ARCH::AARCH64>(uint64_t from, uint64_t shift) {
       relocation.address(relocation.address() + shift);
     }
 
-    if (relocation.encoding() == Relocation::ENCODING::RELR) {
-      continue;
-    }
-
     const Relocation::TYPE type = relocation.type();
 
     switch (type) {
@@ -153,11 +145,6 @@ void Binary::patch_relocations<ARCH::I386>(uint64_t from, uint64_t shift) {
       //shift_code(relocation.address(), shift, relocation.size() / 8);
       relocation.address(relocation.address() + shift);
     }
-
-    if (relocation.encoding() == Relocation::ENCODING::RELR) {
-      continue;
-    }
-
     const Relocation::TYPE type = relocation.type();
 
     switch (type) {
@@ -196,10 +183,6 @@ void Binary::patch_relocations<ARCH::X86_64>(uint64_t from, uint64_t shift) {
       relocation.address(relocation.address() + shift);
     }
 
-    if (relocation.encoding() == Relocation::ENCODING::RELR) {
-      continue;
-    }
-
     const Relocation::TYPE type = relocation.type();
 
     switch (type) {

diff --git a/tests/elf/test_relr_relocations.py b/tests/elf/test_relr_relocations.py
@@ -41,3 +41,11 @@ def test_relr_relocations(tmp_path: Path):
         lib = ctypes.cdll.LoadLibrary(out.as_posix())
         assert lib.cos is not None
 
+def test_relr_addend(tmp_path: Path):
+    elf = lief.ELF.parse(get_sample("ELF/ls-glibc2.40-relr.elf"))
+    elf.relocate_phdr_table()
+    out = tmp_path / "out.elf"
+    elf.write(out.as_posix())
+
+    new_elf = lief.ELF.parse(out)
+    assert new_elf.get_int_from_virtual_address(0x21f40, 8) == 0xa680