tracing/filters: disallow integer values for string filters and vice versa

Impact: fix filter use boundary condition / crash

Make sure filters for string fields don't use integer values and vice
versa.  Getting it wrong can crash the system or produce bogus
results.

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: <1237878882.8339.61.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 9fca8bb1c06bae422367250459b12550f0343457..026be412f356d9d6642480a3db01770611f7337f 100644 (file)
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -237,9 +237,14 @@ int filter_add_pred(struct ftrace_event_call *call, struct filter_pred *pred)
        pred->offset = field->offset;
 
        if (is_string_field(field->type)) {
+               if (!pred->str_val)
+                       return -EINVAL;
                pred->fn = filter_pred_string;
                pred->str_len = field->size;
                return __filter_add_pred(call, pred);
+       } else {
+               if (pred->str_val)
+                       return -EINVAL;
        }
 
        switch (field->size) {