From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932541AbaHHUvk (ORCPT ); Fri, 8 Aug 2014 16:51:40 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:41020 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757057AbaHHUvf (ORCPT ); Fri, 8 Aug 2014 16:51:35 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Daniel Borkmann , "David S. Miller" , Kamal Mostafa Subject: [PATCH 3.13 234/259] net: sctp: check proc_dointvec result in proc_sctp_do_auth Date: Fri, 8 Aug 2014 13:40:57 -0700 Message-Id: <1407530482-4483-235-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1407530482-4483-1-git-send-email-kamal@canonical.com> References: <1407530482-4483-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11.6 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Borkmann [ Upstream commit 24599e61b7552673dd85971cf5a35369cd8c119e ] 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: Kamal Mostafa --- 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 7c4eac4..99abe1a 100644 --- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c @@ -423,8 +423,7 @@ 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