From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vasiliy Kulikov 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> Cc: Alexander Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org To: kernel-janitors@vger.kernel.org Return-path: 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 Sender: linux-fsdevel-owner@vger.kernel.org List-ID: 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