From patchwork Wed Jan 16 15:55:06 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Herton Ronaldo Krzesinski X-Patchwork-Id: 212684 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from chlorine.canonical.com (chlorine.canonical.com [91.189.94.204]) by ozlabs.org (Postfix) with ESMTP id 5B7862C0085 for ; Thu, 17 Jan 2013 03:05:01 +1100 (EST) Received: from localhost ([127.0.0.1] helo=chlorine.canonical.com) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1TvVTu-0003Sf-Mu; Wed, 16 Jan 2013 16:04:51 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1TvVTI-00033H-HQ for kernel-team@lists.ubuntu.com; Wed, 16 Jan 2013 16:04:13 +0000 Received: from [177.132.109.150] (helo=canonical.com) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1TvVTH-0006pG-Q5; Wed, 16 Jan 2013 16:04:12 +0000 From: Herton Ronaldo Krzesinski To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 106/222] NFS: avoid NULL dereference in nfs_destroy_server Date: Wed, 16 Jan 2013 13:55:06 -0200 Message-Id: <1358351822-7675-107-git-send-email-herton.krzesinski@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1358351822-7675-1-git-send-email-herton.krzesinski@canonical.com> References: <1358351822-7675-1-git-send-email-herton.krzesinski@canonical.com> X-Extended-Stable: 3.5 Cc: NeilBrown , Trond Myklebust X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.13 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: kernel-team-bounces@lists.ubuntu.com Errors-To: kernel-team-bounces@lists.ubuntu.com 3.5.7.3 -stable review patch. If anyone has any objections, please let me know. ------------------ From: NeilBrown commit f259613a1e4b44a0cf85a5dafd931be96ee7c9e5 upstream. In rare circumstances, nfs_clone_server() of a v2 or v3 server can get an error between setting server->destory (to nfs_destroy_server), and calling nfs_start_lockd (which will set server->nlm_host). If this happens, nfs_clone_server will call nfs_free_server which will call nfs_destroy_server and thence nlmclnt_done(NULL). This causes the NULL to be dereferenced. So add a guard to only call nlmclnt_done() if ->nlm_host is not NULL. The other guards there are irrelevant as nlm_host can only be non-NULL if one of these flags are set - so remove those tests. (Thanks to Trond for this suggestion). This is suitable for any stable kernel since 2.6.25. Signed-off-by: NeilBrown Signed-off-by: Trond Myklebust Signed-off-by: Herton Ronaldo Krzesinski --- fs/nfs/client.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/nfs/client.c b/fs/nfs/client.c index f005b5b..ede78be 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -689,8 +689,7 @@ static int nfs_create_rpc_client(struct nfs_client *clp, */ static void nfs_destroy_server(struct nfs_server *server) { - if (!(server->flags & NFS_MOUNT_LOCAL_FLOCK) || - !(server->flags & NFS_MOUNT_LOCAL_FCNTL)) + if (server->nlm_host) nlmclnt_done(server->nlm_host); }