Re: [PATCH] tracing: Fix lock imbalance in s_start() memory allocation failure path

[Steven Rostedt]

On Mon, 29 Sep 2025 07:32:38 -0400
Sasha Levin <sashal@xxxxxxxxxx> wrote:

> iff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
> index 9f3e9537417d5..e00da4182deb7 100644
> --- a/kernel/trace/trace_events.c
> +++ b/kernel/trace/trace_events.c
> @@ -1629,11 +1629,10 @@ static void *s_start(struct seq_file *m, loff_t *pos)
>  	loff_t l;
>  
>  	iter = kzalloc(sizeof(*iter), GFP_KERNEL);
> +	mutex_lock(&event_mutex);
>  	if (!iter)
>  		return NULL;
>  
> -	mutex_lock(&event_mutex);
> -
>  	iter->type = SET_EVENT_FILE;
>  	iter->file = list_entry(&tr->events, struct trace_event_file, list);
>  

Good catch, thanks!

-- Steve