From 47c1856971dd05cac730f70d073518da021b2e5c Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 29 Jun 2016 19:55:59 -0500 Subject: [PATCH] tracing: Fix use-after-free in hist_unreg_all/hist_enable_unreg_all While running tools/testing/selftests test suite with KASAN, Dmitry Vyukov hit the following use-after-free report: ================================================================== BUG: KASAN: use-after-free in hist_unreg_all+0x1a1/0x1d0 at addr ffff880031632cc0 Read of size 8 by task ftracetest/7413 ================================================================== BUG kmalloc-128 (Not tainted): kasan: bad access detected ------------------------------------------------------------------ This fixes the problem, along with the same problem in hist_enable_unreg_all(). Link: http://lkml.kernel.org/r/c3d05b79e42555b6e36a3a99aae0e37315ee5304.1467247517.git.tom.zanussi@linux.intel.com Cc: Dmitry Vyukov [Copied Steve's hist_enable_unreg_all() fix to hist_unreg_all()] Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt --- kernel/trace/trace_events_hist.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 0c05b8a99806..19ae135120a3 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -1500,9 +1500,9 @@ static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops, static void hist_unreg_all(struct trace_event_file *file) { - struct event_trigger_data *test; + struct event_trigger_data *test, *n; - list_for_each_entry_rcu(test, &file->triggers, list) { + list_for_each_entry_safe(test, n, &file->triggers, list) { if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { list_del_rcu(&test->list); trace_event_trigger_enable_disable(file, 0); @@ -1699,9 +1699,9 @@ hist_enable_get_trigger_ops(char *cmd, char *param) static void hist_enable_unreg_all(struct trace_event_file *file) { - struct event_trigger_data *test; + struct event_trigger_data *test, *n; - list_for_each_entry_rcu(test, &file->triggers, list) { + list_for_each_entry_safe(test, n, &file->triggers, list) { if (test->cmd_ops->trigger_type == ETT_HIST_ENABLE) { list_del_rcu(&test->list); update_cond_flag(file); -- 2.20.1