Commit ee6cdabc authored Mar 23, 2009 by Tom Zanussi Committed by Ingo Molnar Mar 23, 2009

tracing/filters: fix bug in copy_pred()



Impact: fix potential crash on subsystem filter expression freeing

When making a copy of the predicate, pred->field_name needs to be
duplicated in the copy as well, otherwise bad things can happen due to
later multiple frees of the same string.

This affects only per-subsystem event filtering.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: =?ISO-8859-1?Q?Fr=E9d=E9ric?= Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1237796802.7527.39.camel@charm-linux>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 75c8b417

kernel/trace/trace_events_filter.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -276,11 +276,19 @@ static struct filter_pred copy_pred(struct filter_pred pred)
		return NULL;

		memcpy(new_pred, pred, sizeof(*pred));

		if (pred->field_name) {
		new_pred->field_name = kstrdup(pred->field_name, GFP_KERNEL);
		if (!new_pred->field_name) {
		kfree(new_pred);
		return NULL;
		}
		}

		if (pred->str_val) {
		new_pred->str_val = kstrdup(pred->str_val, GFP_KERNEL);
		new_pred->field_name = kstrdup(pred->field_name, GFP_KERNEL);
		if (!new_pred->str_val) {
		kfree(new_pred);
		filter_free_pred(new_pred);
		return NULL;
		}
		}