From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 047A4C433EF for ; Sat, 28 May 2022 02:52:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355565AbiE1Cwy (ORCPT ); Fri, 27 May 2022 22:52:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231347AbiE1Cww (ORCPT ); Fri, 27 May 2022 22:52:52 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 08193880C6; Fri, 27 May 2022 19:52:51 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 98A9B61D29; Sat, 28 May 2022 02:52:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 10E88C34114; Sat, 28 May 2022 02:52:50 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.95) (envelope-from ) id 1numZN-000LKR-0j; Fri, 27 May 2022 22:52:49 -0400 Message-ID: <20220528025248.861126787@goodmis.org> User-Agent: quilt/0.66 Date: Fri, 27 May 2022 22:50:29 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , stable@vger.kernel.org, Stephen Rothwell Subject: [for-next][PATCH 01/23] tracing: Have event format check not flag %p* on __get_dynamic_array() References: <20220528025028.850906216@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Steven Rostedt (Google)" The print fmt check against trace events to make sure that the format does not use pointers that may be freed from the time of the trace to the time the event is read, gives a false positive on %pISpc when reading data that was saved in __get_dynamic_array() when it is perfectly fine to do so, as the data being read is on the ring buffer. Link: https://lore.kernel.org/all/20220407144524.2a592ed6@canb.auug.org.au/ Cc: stable@vger.kernel.org Fixes: 5013f454a352c ("tracing: Add check of trace event print fmts for dereferencing pointers") Reported-by: Stephen Rothwell Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_events.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 78f313b7b315..d5913487821a 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -392,12 +392,6 @@ static void test_event_printk(struct trace_event_call *call) if (!(dereference_flags & (1ULL << arg))) goto next_arg; - /* Check for __get_sockaddr */; - if (str_has_prefix(fmt + i, "__get_sockaddr(")) { - dereference_flags &= ~(1ULL << arg); - goto next_arg; - } - /* Find the REC-> in the argument */ c = strchr(fmt + i, ','); r = strstr(fmt + i, "REC->"); @@ -413,7 +407,14 @@ static void test_event_printk(struct trace_event_call *call) a = strchr(fmt + i, '&'); if ((a && (a < r)) || test_field(r, call)) dereference_flags &= ~(1ULL << arg); + } else if ((r = strstr(fmt + i, "__get_dynamic_array(")) && + (!c || r < c)) { + dereference_flags &= ~(1ULL << arg); + } else if ((r = strstr(fmt + i, "__get_sockaddr(")) && + (!c || r < c)) { + dereference_flags &= ~(1ULL << arg); } + next_arg: i--; arg++; -- 2.35.1