From: Zheng Wang <zyytlz.wz@xxxxxxx>
In some specific situation, the return value of __bch_btree_node_alloc may
be NULL. This may lead to poential NULL pointer dereference in caller
function like a calling chaion :
btree_split->bch_btree_node_alloc->__bch_btree_node_alloc.
Fix it by initialize return value in __bch_btree_node_alloc before return.
Fixes: cafe56359144 ("bcache: A block layer cache")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Zheng Wang <zyytlz.wz@xxxxxxx>
Signed-off-by: Coly Li <colyli@xxxxxxx>
---
drivers/md/bcache/btree.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 7c21e54468bf..0ddf91204782 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -1090,10 +1090,12 @@ struct btree *__bch_btree_node_alloc(struct cache_set *c, struct btree_op *op,
struct btree *parent)
{
BKEY_PADDED(key) k;
- struct btree *b = ERR_PTR(-EAGAIN);
+ struct btree *b;
mutex_lock(&c->bucket_lock);
retry:
+ /* return ERR_PTR(-EAGAIN) when it fails */
+ b = ERR_PTR(-EAGAIN);
if (__bch_bucket_alloc_set(c, RESERVE_BTREE, &k.key, wait))
goto err;
--
2.35.3
