Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932328AbcDJTR6 (ORCPT ); Sun, 10 Apr 2016 15:17:58 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:54101 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932694AbcDJTJF (ORCPT ); Sun, 10 Apr 2016 15:09:05 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Wheeler Subject: [PATCH 4.4 124/210] bcache: fix cache_set_flush() NULL pointer dereference on OOM Date: Sun, 10 Apr 2016 11:35:45 -0700 Message-Id: <20160410183531.027341590@linuxfoundation.org> X-Mailer: git-send-email 2.8.0 In-Reply-To: <20160410183526.651820045@linuxfoundation.org> References: <20160410183526.651820045@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 992 Lines: 34 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ 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 --- drivers/md/bcache/super.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1373,6 +1373,9 @@ static void cache_set_flush(struct closu struct btree *b; unsigned i; + if (!c) + closure_return(cl); + bch_cache_accounting_destroy(&c->accounting); kobject_put(&c->internal);