From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vasiliy Kulikov Date: Wed, 10 Nov 2010 20:38:02 +0000 Subject: [PATCH] fs: select: fix information leak to userspace Message-Id: <1289421483-23907-1-git-send-email-segooon@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: kernel-janitors@vger.kernel.org Cc: Alexander Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org On some architectures __kernel_suseconds_t is int. On these archs struct timeval has padding bytes at the end. This struct is copied to userspace with these padding bytes uninitialized. This leads to leaking of contents of kernel stack memory. This bug was added with v2.6.27-rc5-286-gb773ad4. Signed-off-by: Vasiliy Kulikov --- Compile tested. fs/select.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/fs/select.c b/fs/select.c index b7b10aa..32cf018 100644 --- a/fs/select.c +++ b/fs/select.c @@ -306,6 +306,7 @@ static int poll_select_copy_remaining(struct timespec *end_time, void __user *p, rts.tv_sec = rts.tv_nsec = 0; if (timeval) { + memset(&rtv, 0, sizeof(rtv)); rtv.tv_sec = rts.tv_sec; rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC; -- 1.7.0.4 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756418Ab0KJUiN (ORCPT ); Wed, 10 Nov 2010 15:38:13 -0500 Received: from mail-ey0-f174.google.com ([209.85.215.174]:43462 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755341Ab0KJUiL (ORCPT ); Wed, 10 Nov 2010 15:38:11 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer; b=bFBhPRM42LeWHzPK7p7nHmM5Eq863fYDVCRCnqh1LZ0Jgg4Zrd9pPJr0++tjDBQVm3 tJJeuP0fBzRNonvBI15ggEVw2jNH7m+vh/FFYL8pMsqOgGkcZ5NoZsXm1tinKeP/RsDa 2u9X/vQI3PdVOagAW0WSfsSZvDgcxckpla4Fc= From: Vasiliy Kulikov To: kernel-janitors@vger.kernel.org Cc: Alexander Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] fs: select: fix information leak to userspace Date: Wed, 10 Nov 2010 23:38:02 +0300 Message-Id: <1289421483-23907-1-git-send-email-segooon@gmail.com> X-Mailer: git-send-email 1.7.0.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On some architectures __kernel_suseconds_t is int. On these archs struct timeval has padding bytes at the end. This struct is copied to userspace with these padding bytes uninitialized. This leads to leaking of contents of kernel stack memory. This bug was added with v2.6.27-rc5-286-gb773ad4. Signed-off-by: Vasiliy Kulikov --- Compile tested. fs/select.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/fs/select.c b/fs/select.c index b7b10aa..32cf018 100644 --- a/fs/select.c +++ b/fs/select.c @@ -306,6 +306,7 @@ static int poll_select_copy_remaining(struct timespec *end_time, void __user *p, rts.tv_sec = rts.tv_nsec = 0; if (timeval) { + memset(&rtv, 0, sizeof(rtv)); rtv.tv_sec = rts.tv_sec; rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC; -- 1.7.0.4