From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754526AbaHRKCE (ORCPT ); Mon, 18 Aug 2014 06:02:04 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:42601 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752322AbaHRJeT (ORCPT ); Mon, 18 Aug 2014 05:34:19 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Daniel Borkmann , "David S. Miller" , Luis Henriques Subject: [PATCH 3.11 037/137] net: sctp: check proc_dointvec result in proc_sctp_do_auth Date: Mon, 18 Aug 2014 10:31:38 +0100 Message-Id: <1408354398-10226-38-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1408354398-10226-1-git-send-email-luis.henriques@canonical.com> References: <1408354398-10226-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.11.10.15 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Borkmann commit 24599e61b7552673dd85971cf5a35369cd8c119e upstream. When writing to the sysctl field net.sctp.auth_enable, it can well be that the user buffer we handed over to proc_dointvec() via proc_sctp_do_auth() handler contains something other than integers. In that case, we would set an uninitialized 4-byte value from the stack to net->sctp.auth_enable that can be leaked back when reading the sysctl variable, and it can unintentionally turn auth_enable on/off based on the stack content since auth_enable is interpreted as a boolean. Fix it up by making sure proc_dointvec() returned sucessfully. Fixes: b14878ccb7fa ("net: sctp: cache auth_enable per endpoint") Reported-by: Florian Westphal Signed-off-by: Daniel Borkmann Acked-by: Neil Horman Acked-by: Vlad Yasevich Signed-off-by: David S. Miller Signed-off-by: Luis Henriques --- net/sctp/sysctl.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c index e41a43470b84..1fce794c9274 100644 --- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c @@ -368,8 +368,7 @@ static int proc_sctp_do_auth(struct ctl_table *ctl, int write, tbl.data = &net->sctp.auth_enable; ret = proc_dointvec(&tbl, write, buffer, lenp, ppos); - - if (write) { + if (write && ret == 0) { struct sock *sk = net->sctp.ctl_sock; net->sctp.auth_enable = new_value; -- 1.9.1