From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757900Ab0IRTxv (ORCPT ); Sat, 18 Sep 2010 15:53:51 -0400 Received: from kroah.org ([198.145.64.141]:51357 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755012Ab0IRTBj (ORCPT ); Sat, 18 Sep 2010 15:01:39 -0400 X-Mailbox-Line: From gregkh@clark.site Sat Sep 18 11:59:56 2010 Message-Id: <20100918185956.759306842@clark.site> User-Agent: quilt/0.48-11.2 Date: Sat, 18 Sep 2010 11:58:10 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Robert Swiecki , Eugene Teo , Chris Wright , Steven Rostedt Subject: [046/123] tracing: t_start: reset FTRACE_ITER_HASH in case of seek/pread References: <20100918185724.290702750@clark.site> Content-Disposition: inline; filename=tracing-t_start-reset-ftrace_iter_hash-in-case-of-seek-pread.patch In-Reply-To: <20100918190024.GA14388@kroah.com> 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: Greg Kroah-Hartman --- kernel/trace/ftrace.c | 2 ++ 1 file changed, 2 insertions(+) --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1480,6 +1480,8 @@ static void *t_start(struct seq_file *m, 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; }