tracing/filters: Don't use pred on alloc failure

Dan Carpenter sent me a fix to prevent pred from being used if
it couldn't be allocated.  I noticed the same problem also
existed for the create_pred() case and added a fix for that.

Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <1249746549.6453.29.camel@tropicana>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 4 insertions, 0 deletions

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 936c621bbf46..1557148be34b 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1029,6 +1029,8 @@ static int replace_preds(struct event_subsystem *system,
 
                 if (elt->op == OP_AND || elt->op == OP_OR) {
                         pred = create_logical_pred(elt->op);
+                        if (!pred)
+                                return -ENOMEM;
                         if (call) {
                                 err = filter_add_pred(ps, call, pred);
                                 filter_free_pred(pred);
@@ -1048,6 +1050,8 @@ static int replace_preds(struct event_subsystem *system,
                 }
 
                 pred = create_pred(elt->op, operand1, operand2);
+                if (!pred)
+                        return -ENOMEM;
                 if (call) {
                         err = filter_add_pred(ps, call, pred);
                         filter_free_pred(pred);