tools lib traceevent: Fix a possibly wrong memory dereference

If set_op_prio() failed, the token will be freed at out_free,
then arg->op.op would turn out to be a dangle pointer. After
returning EVENT_ERROR from process_op(), free_arg() will be
called and then it will finally see the dangling pointer.

Cc: Borislav Petkov <bp@alien8.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1337740619-27925-13-git-send-email-namhyung.kim@lge.com
Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index d598b376e3c1204a046790c41083949ffdd64140..445a43ad42fd74531e01831329f5290b59e9b0c3 100644 (file)
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -1715,6 +1715,8 @@ process_op(struct event_format *event, struct print_arg *arg, char **tok)
 
                if (set_op_prio(arg) == -1) {
                        event->flags |= EVENT_FL_FAILED;
+                       /* arg->op.op (= token) will be freed at out_free */
+                       arg->op.op = NULL;
                        goto out_free;
                }