From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 75B1A17756 for ; Wed, 9 Aug 2023 11:21:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC815C433C7; Wed, 9 Aug 2023 11:21:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1691580080; bh=lCAdfPtfbZ95AHD9vH+OTBCvmvTGrBFHXnOVC0aqCug=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N80qDUoPmk83HOEtvaUDcIlq7Kdr+ZN31Lr5AGQTFNnQ5g5L7Y7/AbcYLZrS+5ElX 25hsQUtuhB2hsiQDe9M8UyTtOHYwf11iYO/29h5/BrxgU7Bo2WQ6zNrJWeKvLrca3V yUd1g2VzStuDhI8gM3MLzqpQmdVcDPW3jTyvNmsg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zheng Wang , Coly Li , Jens Axboe , Sasha Levin Subject: [PATCH 4.19 220/323] bcache: Fix __bch_btree_node_alloc to make the failure behavior consistent Date: Wed, 9 Aug 2023 12:40:58 +0200 Message-ID: <20230809103708.164534426@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230809103658.104386911@linuxfoundation.org> References: <20230809103658.104386911@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Zheng Wang [ Upstream commit 80fca8a10b604afad6c14213fdfd816c4eda3ee4 ] 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@vger.kernel.org Signed-off-by: Zheng Wang Signed-off-by: Coly Li Link: https://lore.kernel.org/r/20230615121223.22502-6-colyli@suse.de Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- 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 40eea56b9c900..71d670934a07e 100644 --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -1125,10 +1125,12 @@ 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; -- 2.39.2