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>
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index c4a413b..fd01d80 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -276,11 +276,19 @@
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;
}
}
