From: Zheng Wang <zyytlz.wz@163.com>
To: colyli@suse.de
Cc: hackerzheng666@gmail.com, kent.overstreet@gmail.com,
linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org,
alex000young@gmail.com, Zheng Wang <zyytlz.wz@163.com>,
stable@vger.kernel.org
Subject: [RESEND PATCH v3] bcache: Fix __bch_btree_node_alloc to make the failure behavior consistent
Date: Sat, 18 Feb 2023 15:23:35 +0800 [thread overview]
Message-ID: <20230218072335.1537099-1-zyytlz.wz@163.com> (raw)
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@vger.kernel.org
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
---
v3:
- Add Cc: stable@vger.kernel.org suggested by Eric
v2:
- split patch v1 into two patches to make it clearer suggested by Coly Li
---
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 147c493a989a..cae25e74b9e0 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;
--
2.25.1
next reply other threads:[~2023-02-18 7:24 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-18 7:23 Zheng Wang [this message]
2023-02-18 15:22 ` [RESEND PATCH v3] bcache: Fix __bch_btree_node_alloc to make the failure behavior consistent Coly Li
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