From nobody Fri Dec 19 04:01:22 2025 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 48F83EEB57E for ; Sat, 9 Sep 2023 03:23:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238461AbjIIDXr (ORCPT ); Fri, 8 Sep 2023 23:23:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59112 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232883AbjIIDXg (ORCPT ); Fri, 8 Sep 2023 23:23:36 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B24AD1FEF; Fri, 8 Sep 2023 20:23:32 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95669C433C9; Sat, 9 Sep 2023 03:23:30 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.96) (envelope-from ) id 1qeoZZ-000YfT-0f; Fri, 08 Sep 2023 23:23:49 -0400 Message-ID: <20230909032349.020450746@goodmis.org> User-Agent: quilt/0.66 Date: Fri, 08 Sep 2023 23:16:20 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Andrew Morton , stable@vger.kernel.org, Zheng Yejian , Linux Kernel Functional Testing , Naresh Kamboju Subject: [for-linus][PATCH 05/15] tracing: Have tracing_max_latency inc the trace array ref count References: <20230909031615.047488015@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Steven Rostedt (Google)" The tracing_max_latency file points to the trace_array max_latency field. For an instance, if the file is opened and the instance is deleted, reading or writing to the file will cause a use after free. Up the ref count of the trace_array when tracing_max_latency is opened. Link: https://lkml.kernel.org/r/20230907024803.666889383@goodmis.org Link: https://lore.kernel.org/all/1cb3aee2-19af-c472-e265-05176fe9bd84@huaw= ei.com/ Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Andrew Morton Cc: Zheng Yejian Fixes: 8530dec63e7b4 ("tracing: Add tracing_check_open_get_tr()") Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 0827037ee3b8..c8b8b4c6feaf 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1772,7 +1772,7 @@ static void trace_create_maxlat_file(struct trace_arr= ay *tr, init_irq_work(&tr->fsnotify_irqwork, latency_fsnotify_workfn_irq); tr->d_max_latency =3D trace_create_file("tracing_max_latency", TRACE_MODE_WRITE, - d_tracer, &tr->max_latency, + d_tracer, tr, &tracing_max_lat_fops); } =20 @@ -1805,7 +1805,7 @@ void latency_fsnotify(struct trace_array *tr) =20 #define trace_create_maxlat_file(tr, d_tracer) \ trace_create_file("tracing_max_latency", TRACE_MODE_WRITE, \ - d_tracer, &tr->max_latency, &tracing_max_lat_fops) + d_tracer, tr, &tracing_max_lat_fops) =20 #endif =20 @@ -6717,14 +6717,18 @@ static ssize_t tracing_max_lat_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { - return tracing_nsecs_read(filp->private_data, ubuf, cnt, ppos); + struct trace_array *tr =3D filp->private_data; + + return tracing_nsecs_read(&tr->max_latency, ubuf, cnt, ppos); } =20 static ssize_t tracing_max_lat_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { - return tracing_nsecs_write(filp->private_data, ubuf, cnt, ppos); + struct trace_array *tr =3D filp->private_data; + + return tracing_nsecs_write(&tr->max_latency, ubuf, cnt, ppos); } =20 #endif @@ -7778,10 +7782,11 @@ static const struct file_operations tracing_thresh_= fops =3D { =20 #ifdef CONFIG_TRACER_MAX_TRACE static const struct file_operations tracing_max_lat_fops =3D { - .open =3D tracing_open_generic, + .open =3D tracing_open_generic_tr, .read =3D tracing_max_lat_read, .write =3D tracing_max_lat_write, .llseek =3D generic_file_llseek, + .release =3D tracing_release_generic_tr, }; #endif =20 --=20 2.40.1