4.9-stable review patch. If anyone has any objections, please let me know.
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From: Steven Rostedt (VMware) rostedt@goodmis.org
commit 3cec638b3d793b7cacdec5b8072364b41caeb0e1 upstream.
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: bac5fb97a173a ("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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/trace/trace_events_trigger.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -742,8 +742,10 @@ 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);