tracing: add run-time field descriptions for event filtering, kfree fix

Impact: fix potential kfree of random data in (rare) failure path

Zero-initialize the field structure.

Reported-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <1237710639.7703.46.camel@charm-linux>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 6 insertions, 1 deletions

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 97d4daaddd9a..594d78aaa185 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -24,26 +24,31 @@ int trace_define_field(struct ftrace_event_call *call, char *type,
 {
         struct ftrace_event_field *field;
 
-        field = kmalloc(sizeof(*field), GFP_KERNEL);
+        field = kzalloc(sizeof(*field), GFP_KERNEL);
         if (!field)
                 goto err;
+
         field->name = kstrdup(name, GFP_KERNEL);
         if (!field->name)
                 goto err;
+
         field->type = kstrdup(type, GFP_KERNEL);
         if (!field->type)
                 goto err;
+
         field->offset = offset;
         field->size = size;
         list_add(&field->link, &call->fields);
 
         return 0;
+
 err:
         if (field) {
                 kfree(field->name);
                 kfree(field->type);
         }
         kfree(field);
+
         return -ENOMEM;
 }