linux-kernel - [for-linus][PATCH 1/2] tracing: Fix permissions for the buffer

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Date:   Wed, 03 May 2023 19:14:47 -0400
From:   Steven Rostedt <rostedt@...dmis.org>
To:     linux-kernel@...r.kernel.org
Cc:     Masami Hiramatsu <mhiramat@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        stable@...r.kernel.org, Ondrej Mosnacek <omosnace@...hat.com>
Subject: [for-linus][PATCH 1/2] tracing: Fix permissions for the buffer_percent file

From: Ondrej Mosnacek <omosnace@...hat.com>

This file defines both read and write operations, yet it is being
created as read-only. This means that it can't be written to without the
CAP_DAC_OVERRIDE capability. Fix the permissions to allow root to write
to it without the need to override DAC perms.

Link: https://lore.kernel.org/linux-trace-kernel/20230503140114.3280002-1-omosnace@redhat.com

Cc: stable@...r.kernel.org
Cc: Masami Hiramatsu <mhiramat@...nel.org>
Fixes: 03329f993978 ("tracing: Add tracefs file buffer_percentage")
Signed-off-by: Ondrej Mosnacek <omosnace@...hat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@...dmis.org>
---
 kernel/trace/trace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 076d893d2965..b9be1af23a73 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -9660,7 +9660,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
 
 	tr->buffer_percent = 50;
 
-	trace_create_file("buffer_percent", TRACE_MODE_READ, d_tracer,
+	trace_create_file("buffer_percent", TRACE_MODE_WRITE, d_tracer,
 			tr, &buffer_percent_fops);
 
 	create_trace_options_dir(tr);
-- 
2.39.2