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authorDmitry Antipov <dmantipov@yandex.ru>2025-06-06 14:22:42 +0300
committerSteven Rostedt (Google) <rostedt@goodmis.org>2025-06-06 20:25:55 -0400
commit40ee2afafc1d9fe3aa44a6fbe440d78a5c96a72e (patch)
treed17e9e11074f0f66de1710515d5f11d463c063a7
parenta9d0aab5eb33a44792a66b7af13ff50d7b3e7022 (diff)
downloadlinux-40ee2afafc1d9fe3aa44a6fbe440d78a5c96a72e.tar.gz
ring-buffer: Fix buffer locking in ring_buffer_subbuf_order_set()
Enlarge the critical section in ring_buffer_subbuf_order_set() to ensure that error handling takes place with per-buffer mutex held, thus preventing list corruption and other concurrency-related issues. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Link: https://lore.kernel.org/20250606112242.1510605-1-dmantipov@yandex.ru Reported-by: syzbot+05d673e83ec640f0ced9@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=05d673e83ec640f0ced9 Fixes: f9b94daa542a8 ("ring-buffer: Set new size of the ring buffer sub page") Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-rw-r--r--kernel/trace/ring_buffer.c4
1 files changed, 1 insertions, 3 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index e24509bd0af554..00fc38d70e868a 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -6795,7 +6795,7 @@ int ring_buffer_subbuf_order_set(struct trace_buffer *buffer, int order)
old_size = buffer->subbuf_size;
/* prevent another thread from changing buffer sizes */
- mutex_lock(&buffer->mutex);
+ guard(mutex)(&buffer->mutex);
atomic_inc(&buffer->record_disabled);
/* Make sure all commits have finished */
@@ -6900,7 +6900,6 @@ int ring_buffer_subbuf_order_set(struct trace_buffer *buffer, int order)
}
atomic_dec(&buffer->record_disabled);
- mutex_unlock(&buffer->mutex);
return 0;
@@ -6909,7 +6908,6 @@ error:
buffer->subbuf_size = old_size;
atomic_dec(&buffer->record_disabled);
- mutex_unlock(&buffer->mutex);
for_each_buffer_cpu(buffer, cpu) {
cpu_buffer = buffer->buffers[cpu];