Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932945AbbHXJPf (ORCPT ); Mon, 24 Aug 2015 05:15:35 -0400 Received: from mx2.suse.de ([195.135.220.15]:58412 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932849AbbHXJKT (ORCPT ); Mon, 24 Aug 2015 05:10:19 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, "Amanieu d'Antras" , Oleg Nesterov , Ingo Molnar , Andrew Morton , Linus Torvalds , Jiri Slaby Subject: [PATCH 3.12 67/82] signalfd: fix information leak in signalfd_copyinfo Date: Mon, 24 Aug 2015 11:09:27 +0200 Message-Id: X-Mailer: git-send-email 2.5.0 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1771 Lines: 49 From: Amanieu d'Antras 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 3ead7c52bdb0ab44f4bb1feed505a8323cc12ba7 upstream. This function may copy the si_addr_lsb field to user mode when it hasn't been initialized, which can leak kernel stack data to user mode. Just checking the value of si_code is insufficient because the same si_code value is shared between multiple signals. This is solved by checking the value of si_signo in addition to si_code. Signed-off-by: Amanieu d'Antras Cc: Oleg Nesterov Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Jiri Slaby --- fs/signalfd.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/signalfd.c b/fs/signalfd.c index 424b7b65321f..148f8e7af882 100644 --- a/fs/signalfd.c +++ b/fs/signalfd.c @@ -121,8 +121,9 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo, * Other callers might not initialize the si_lsb field, * so check explicitly for the right codes here. */ - if (kinfo->si_code == BUS_MCEERR_AR || - kinfo->si_code == BUS_MCEERR_AO) + if (kinfo->si_signo == SIGBUS && + (kinfo->si_code == BUS_MCEERR_AR || + kinfo->si_code == BUS_MCEERR_AO)) err |= __put_user((short) kinfo->si_addr_lsb, &uinfo->ssi_addr_lsb); #endif -- 2.5.0 -- 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/