From: Coly Li <colyli@suse.de>
Date: Mon, 20 Nov 2023 05:24:55 +0000 (+0800)
Subject: bcache: check return value from btree_node_alloc_replacement()
X-Git-Tag: v4.14.332~17
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0fe5539061f8e06ff734ed41215c7bbbdffe10a2;p=thirdparty%2Fkernel%2Fstable.git

bcache: check return value from btree_node_alloc_replacement()

commit 777967e7e9f6f5f3e153abffb562bffaf4430d26 upstream.

In btree_gc_rewrite_node(), pointer 'n' is not checked after it returns
from btree_gc_rewrite_node(). There is potential possibility that 'n' is
a non NULL ERR_PTR(), referencing such error code is not permitted in
following code. Therefore a return value checking is necessary after 'n'
is back from btree_node_alloc_replacement().

Signed-off-by: Coly Li <colyli@suse.de>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Cc:  <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20231120052503.6122-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index fba0fff8040d6..37ac4e8462056 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -1483,6 +1483,8 @@ static int btree_gc_rewrite_node(struct btree *b, struct btree_op *op,
 		return 0;
 
 	n = btree_node_alloc_replacement(replace, NULL);
+	if (IS_ERR(n))
+		return 0;
 
 	/* recheck reserve after allocating replacement node */
 	if (btree_check_reserve(b, NULL)) {