Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932605AbcDBBYh (ORCPT ); Fri, 1 Apr 2016 21:24:37 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:54166 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932571AbcDBAz7 (ORCPT ); Fri, 1 Apr 2016 20:55:59 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Eric Wheeler , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 073/170] bcache: fix cache_set_flush() NULL pointer dereference on OOM Date: Fri, 1 Apr 2016 17:52:39 -0700 Message-Id: <1459558456-24452-74-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1459558456-24452-1-git-send-email-kamal@canonical.com> References: <1459558456-24452-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1147 Lines: 36 3.19.8-ckt18 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Eric Wheeler commit f8b11260a445169989d01df75d35af0f56178f95 upstream. When bch_cache_set_alloc() fails to kzalloc the cache_set, the asyncronous closure handling tries to dereference a cache_set that hadn't yet been allocated inside of cache_set_flush() which is called by __cache_set_unregister() during cleanup. This appears to happen only during an OOM condition on bcache_register. Signed-off-by: Eric Wheeler Signed-off-by: Kamal Mostafa --- drivers/md/bcache/super.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 2d0650de..2a10283 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1404,6 +1404,9 @@ static void cache_set_flush(struct closure *cl) struct btree *b; unsigned i; + if (!c) + closure_return(cl); + bch_cache_accounting_destroy(&c->accounting); kobject_put(&c->internal); -- 2.7.4