Messages in this thread | | | From | Dmitry Vyukov <> | Date | Wed, 3 Aug 2016 16:19:53 +0200 | Subject | Re: [PATCH 3/4] tracing: Fix use-after-free in hist_unreg_all/hist_enable_unreg_all |
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On Wed, Aug 3, 2016 at 3:54 PM, Steven Rostedt <rostedt@goodmis.org> wrote: > From: Steven Rostedt <rostedt@goodmis.org> > > 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 <dvyukov@google.com>
s/Cc/Reported-by/ please
> [Copied Steve's hist_enable_unreg_all() fix to hist_unreg_all()] > Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> > Signed-off-by: Steven Rostedt <rostedt@goodmis.org> > --- > 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); > -- > 2.8.1 > >
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