From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752507AbcFEKz1 (ORCPT ); Sun, 5 Jun 2016 06:55:27 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:21659 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751906AbcFEKV3 (ORCPT ); Sun, 5 Jun 2016 06:21:29 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eric Wheeler , Eric Wheeler , Greg Kroah-Hartman , Willy Tarreau Subject: [PATCH 3.10 034/143] bcache: fix cache_set_flush() NULL pointer dereference on OOM Date: Sun, 5 Jun 2016 12:18:57 +0200 Message-Id: <1465122046-9645-35-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1465122046-9645-1-git-send-email-w@1wt.eu> References: <1465122046-9645-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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: Greg Kroah-Hartman Signed-off-by: Willy Tarreau --- 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 2d2915f..2a4c13a 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1295,6 +1295,9 @@ static void cache_set_flush(struct closure *cl) set_bit(CACHE_SET_STOPPING_2, &c->flags); wake_up(&c->alloc_wait); + if (!c) + closure_return(cl); + bch_cache_accounting_destroy(&c->accounting); kobject_put(&c->internal); -- 2.8.0.rc2.1.gbe9624a