[PATCH 1/2] objtool: Fix double-free in .cold detection error path

From: Josh Poimboeuf
Date: Tue Nov 20 2018 - 12:53:21 EST


From: Artem Savkov <asavkov@xxxxxxxxxx>

If read_symbols() fails during second list traversal (the one dealing
with ".cold" subfunctions) it frees the symbol, but never deletes it
from the list/hash_table resulting in symbol being freed again in
elf_close(). Fix it by just returning an error, leaving cleanup to
elf_close().

Fixes: 13810435b9a7 ("objtool: Support GCC 8's cold subfunctions")
Signed-off-by: Artem Savkov <asavkov@xxxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
tools/objtool/elf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 6dbb9fae0f9d..e7a7ac40e045 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -312,7 +312,7 @@ static int read_symbols(struct elf *elf)
if (!pfunc) {
WARN("%s(): can't find parent function",
sym->name);
- goto err;
+ return -1;
}

sym->pfunc = pfunc;
--
2.17.2