Commit 3cec638b authored Dec 09, 2018 by Steven Rostedt (VMware)

tracing: Fix memory leak in set_trigger_filter()



When create_event_filter() fails in set_trigger_filter(), the filter may
still be allocated and needs to be freed. The caller expects the
data->filter to be updated with the new filter, even if the new filter
failed (we could add an error message by setting set_str parameter of
create_event_filter(), but that's another update).

But because the error would just exit, filter was left hanging and
nothing could free it.

Found by kmemleak detector.

Cc: stable@vger.kernel.org
Fixes: bac5fb97 ("tracing: Add and use generic set_trigger_filter() implementation")
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

parent b61c1920

kernel/trace/trace_events_trigger.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -732,8 +732,10 @@ int set_trigger_filter(char *filter_str,

		/* The filter is for the 'trigger' event, not the triggered event */
		ret = create_event_filter(file->event_call, filter_str, false, &filter);
		if (ret)
		goto out;
		/*
		* If create_event_filter() fails, filter still needs to be freed.
		* Which the calling code will do with data->filter.
		*/
		assign:
		tmp = rcu_access_pointer(data->filter);

Admin message