[PATCH stable 5.15] lib/buildid: Fix build ID parsing logic

[Jiri Olsa <jolsa@kernel.org>]

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 stable trees that merged 8fa2b6817a95 fix,
the upstream build id code was refactored and returns proper
build id.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Fixes: 8fa2b6817a95 ("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 e41fb0ee405f..cc5da016b235 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