From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753293Ab1ABHWo (ORCPT ); Sun, 2 Jan 2011 02:22:44 -0500 Received: from mail.windriver.com ([147.11.1.11]:34914 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753231Ab1ABHWi (ORCPT ); Sun, 2 Jan 2011 02:22:38 -0500 From: Paul Gortmaker To: stable@kernel.org, linux-kernel@vger.kernel.org Cc: stable-review@kernel.org, Chris Wright , Robert Swiecki , Eugene Teo , Steven Rostedt , Paul Gortmaker Subject: [34-longterm 064/260] tracing: t_start: reset FTRACE_ITER_HASH in case of seek/pread Date: Sun, 2 Jan 2011 02:16:00 -0500 Message-Id: <1293952756-15010-65-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.3.3 In-Reply-To: <1293952756-15010-1-git-send-email-paul.gortmaker@windriver.com> References: <1293952756-15010-1-git-send-email-paul.gortmaker@windriver.com> X-OriginalArrivalTime: 02 Jan 2011 07:21:16.0085 (UTC) FILETIME=[A4987650:01CBAA4D] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chris Wright commit df09162550fbb53354f0c88e85b5d0e6129ee9cc upstream. Be sure to avoid entering t_show() with FTRACE_ITER_HASH set without having properly started the iterator to iterate the hash. This case is degenerate and, as discovered by Robert Swiecki, can cause t_hash_show() to misuse a pointer. This causes a NULL ptr deref with possible security implications. Tracked as CVE-2010-3079. Cc: Robert Swiecki Cc: Eugene Teo Signed-off-by: Chris Wright Signed-off-by: Steven Rostedt Signed-off-by: Paul Gortmaker --- kernel/trace/ftrace.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 7d51cab..73dedb3 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1488,6 +1488,8 @@ static void *t_start(struct seq_file *m, loff_t *pos) if (*pos > 0) return t_hash_start(m, pos); iter->flags |= FTRACE_ITER_PRINTALL; + /* reset in case of seek/pread */ + iter->flags &= ~FTRACE_ITER_HASH; return iter; } -- 1.7.3.3