Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754555AbaGZTSU (ORCPT ); Sat, 26 Jul 2014 15:18:20 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:34123 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753099AbaGZTN1 (ORCPT ); Sat, 26 Jul 2014 15:13:27 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Florian Westphal , Daniel Borkmann , Neil Horman , Vlad Yasevich , "David S. Miller" Subject: [PATCH 3.15 040/109] net: sctp: check proc_dointvec result in proc_sctp_do_auth Date: Sat, 26 Jul 2014 12:02:02 -0700 Message-Id: <20140726190225.052175334@linuxfoundation.org> X-Mailer: git-send-email 2.0.2 In-Reply-To: <20140726190223.834037485@linuxfoundation.org> References: <20140726190223.834037485@linuxfoundation.org> User-Agent: quilt/0.63-1 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 3.15-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: Greg Kroah-Hartman --- net/sctp/sysctl.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c @@ -423,8 +423,7 @@ static int proc_sctp_do_auth(struct ctl_ 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; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/