This is a note to let you know that I've just added the patch titled
bcache: Fix __bch_btree_node_alloc to make the failure behavior consistent
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bcache-fix-__bch_btree_node_alloc-to-make-the-failure-behavior-consistent.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 80fca8a10b604afad6c14213fdfd816c4eda3ee4 Mon Sep 17 00:00:00 2001
From: Zheng Wang <zyytlz.wz@xxxxxxx>
Date: Thu, 15 Jun 2023 20:12:22 +0800
Subject: bcache: Fix __bch_btree_node_alloc to make the failure behavior consistent
From: Zheng Wang <zyytlz.wz@xxxxxxx>
commit 80fca8a10b604afad6c14213fdfd816c4eda3ee4 upstream.
In some specific situations, the return value of __bch_btree_node_alloc
may be NULL. This may lead to a potential NULL pointer dereference in
caller function like a calling chain :
btree_split->bch_btree_node_alloc->__bch_btree_node_alloc.
Fix it by initializing the return value in __bch_btree_node_alloc.
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>
Link: https://lore.kernel.org/r/20230615121223.22502-6-colyli@xxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/bcache/btree.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -1090,10 +1090,12 @@ struct btree *__bch_btree_node_alloc(str
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;
Patches currently in stable-queue which might be from zyytlz.wz@xxxxxxx are
queue-6.4/bcache-fix-__bch_btree_node_alloc-to-make-the-failure-behavior-consistent.patch
queue-6.4/bcache-remove-unnecessary-null-point-check-in-node-allocations.patch
