[PATCH 3/6] tools lib traceevent: Fix a possibly wrong memory dereference

[Arnaldo Carvalho de Melo]

From: Namhyung Kim <namhyung.kim@xxxxxxx>

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@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/r/1337740619-27925-13-git-send-email-namhyung.kim@xxxxxxx
Signed-off-by: Namhyung Kim <namhyung.kim@xxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/lib/traceevent/event-parse.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index d598b37..445a43a 100644
--- 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;
 		}
 
-- 
1.7.9.2.358.g22243

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