From: Steven Rostedt (Google) <rostedt@goodmis.org>
Date: Thu, 7 Sep 2023 02:47:14 +0000 (-0400)
Subject: tracing: Have current_trace inc the trace array ref count
X-Git-Tag: v6.1.61~852
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6dc57c3a1d1361b570b8a77b1c5cb11b5b5706f9;p=platform%2Fkernel%2Flinux-starfive.git

tracing: Have current_trace inc the trace array ref count

commit 9b37febc578b2e1ad76a105aab11d00af5ec3d27 upstream.

The current_trace updates the trace array tracer. 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 current_trace is opened.

Link: https://lkml.kernel.org/r/20230907024803.877687227@goodmis.org
Link: https://lore.kernel.org/all/1cb3aee2-19af-c472-e265-05176fe9bd84@huawei.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Fixes: 8530dec63e7b4 ("tracing: Add tracing_check_open_get_tr()")
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 1ea3f96..5951a0c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -7708,10 +7708,11 @@ static const struct file_operations tracing_max_lat_fops = {
 #endif
 
 static const struct file_operations set_tracer_fops = {
-	.open		= tracing_open_generic,
+	.open		= tracing_open_generic_tr,
 	.read		= tracing_set_trace_read,
 	.write		= tracing_set_trace_write,
 	.llseek		= generic_file_llseek,
+	.release	= tracing_release_generic_tr,
 };
 
 static const struct file_operations tracing_pipe_fops = {