[PATCH stable 6.11] lib/buildid: Fix build ID parsing logic

Jiri Olsa
2024-11-04T17:53:34Z

The parse_build_id_buf does not account Elf32_Nhdr header size
when getting the build id data pointer and returns wrong build
id data as result.

This is problem only for stable trees that merged 768d731b8a0d
fix, the upstream build id code was refactored and returns proper
build id.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Fixes: 768d731b8a0d ("lib/buildid: harden build ID parsing logic")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
lib/buildid.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/buildid.c b/lib/buildid.c
index 26007cc99a38..aee749f2647d 100644
--- a/lib/buildid.c
+++ b/lib/buildid.c
@@ -40,7 +40,7 @@ static int parse_build_id_buf(unsigned char *build_id,
name_sz == note_name_sz &&
memcmp(nhdr + 1, note_name, note_name_sz) == 0 &&
desc_sz > 0 && desc_sz <= BUILD_ID_SIZE_MAX) {
- data = note_start + note_off + ALIGN(note_name_sz, 4);
+ data = note_start + note_off + sizeof(Elf32_Nhdr) + ALIGN(note_name_sz, 4);
memcpy(build_id, data, desc_sz);
memset(build_id + desc_sz, 0, BUILD_ID_SIZE_MAX - desc_sz);
if (size)
--
2.47.0