tracing/filter: Do not allow infix to exceed end of string

[pandora-kernel.git] / kernel / trace / trace_events_filter.c

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 8bcc9bf..bfeb725 100644 (file)
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1027,6 +1027,9 @@ static void parse_init(struct filter_parse_state *ps,
 
 static char infix_next(struct filter_parse_state *ps)
 {
+       if (!ps->infix.cnt)
+               return 0;
+
        ps->infix.cnt--;
 
        return ps->infix.string[ps->infix.tail++];
@@ -1042,6 +1045,9 @@ static char infix_peek(struct filter_parse_state *ps)
 
 static void infix_advance(struct filter_parse_state *ps)
 {
+       if (!ps->infix.cnt)
+               return;
+
        ps->infix.cnt--;
        ps->infix.tail++;
 }