dm btree: fix leak of bufio-backed block in btree_split_sibling error path

The block allocated at the start of btree_split_sibling() is never
released if later insert_at() fails.

Fix this by releasing the previously allocated bufio block using
unlock_block().

Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c
index c573402033b2..0918a7c5f809 100644
--- a/drivers/md/persistent-data/dm-btree.c
+++ b/drivers/md/persistent-data/dm-btree.c
@@ -473,8 +473,10 @@ static int btree_split_sibling(struct shadow_spine *s, unsigned parent_index,
 
         r = insert_at(sizeof(__le64), pn, parent_index + 1,
                       le64_to_cpu(rn->keys[0]), &location);
-        if (r)
+        if (r) {
+                unlock_block(s->info, right);
                 return r;
+        }
 
         if (key < le64_to_cpu(rn->keys[0])) {
                 unlock_block(s->info, right);