Re: [PATCH] tracing / histogram: Fix NULL pointer dereference on strcmp() on NULL event name

From: Tom Zanussi
Date: Wed Aug 11 2021 - 11:29:15 EST


Hi Steve,

On Wed, 2021-08-11 at 10:35 -0400, Steven Rostedt wrote:
> On Sun, 8 Aug 2021 00:30:11 -0400
> Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> > diff --git a/kernel/trace/trace_events_hist.c
> > b/kernel/trace/trace_events_hist.c
> > index 949ef09dc537..a48aa2a2875b 100644
> > --- a/kernel/trace/trace_events_hist.c
> > +++ b/kernel/trace/trace_events_hist.c
> > @@ -3430,6 +3430,8 @@ trace_action_create_field_var(struct
> > hist_trigger_data *hist_data,
> > event = data->match_data.event;
> > }
> >
> > + if (!event)
> > + goto free;
> > /*
> > * At this point, we're looking at a field on another
> > * event. Because we can't modify a hist trigger on
> > --
>
> Tom,
>
> Is this OK? I'm going to start running this through my tests and when
> it's done, I'm going to send it off to Linus.

Sorry, missed this one.

But yeah, this fixes the problem, thanks!

Reviewed-by: Tom Zanussi <zanussi@xxxxxxxxxx>


>
> -- Steve