[PATCH 5.7 013/204] btrfs: ref-verify: fix memory leak in add_block_entry

Greg Kroah-Hartman
2020-08-20T13:20:31Z

From: Tom Rix <trix@redhat.com>

commit d60ba8de1164e1b42e296ff270c622a070ef8fe7 upstream.

clang static analysis flags this error

fs/btrfs/ref-verify.c:290:3: warning: Potential leak of memory pointed to by 're' [unix.Malloc]
kfree(be);
^~~~~

The problem is in this block of code:

if (root_objectid) {
struct root_entry *exist_re;

exist_re = insert_root_entry(&exist->roots, re);
if (exist_re)
kfree(re);
}

There is no 'else' block freeing when root_objectid is 0. Add the
missing kfree to the else branch.

Fixes: fd708b81d972 ("Btrfs: add a extent ref verify tool")
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/btrfs/ref-verify.c | 2 ++
1 file changed, 2 insertions(+)

--- a/fs/btrfs/ref-verify.c
+++ b/fs/btrfs/ref-verify.c
@@ -286,6 +286,8 @@ static struct block_entry *add_block_ent
exist_re = insert_root_entry(&exist->roots, re);
if (exist_re)
kfree(re);
+ } else {
+ kfree(re);
}
kfree(be);
return exist;