On Wed, 29 Jul 2026 12:31:08 -0700 Andrii Nakryiko <[email protected]> wrote:
> On Wed, Jul 29, 2026 at 9:02 AM Oleg Nesterov <[email protected]> wrote: > > > > On 07/29, Breno Leitao wrote: > > > > > > --- a/kernel/events/uprobes.c > > > +++ b/kernel/events/uprobes.c > > > @@ -832,7 +832,7 @@ static struct uprobe *hprobe_expire(struct hprobe > > > *hprobe, bool get) > > > if (try_cmpxchg(&hprobe->state, &hstate, uprobe ? > > > HPROBE_STABLE : HPROBE_GONE)) { > > > /* We won the race, we are the ones to unlock SRCU > > > */ > > > __srcu_read_unlock(&uretprobes_srcu, > > > hprobe->srcu_idx); > > > - return get ? get_uprobe(uprobe) : uprobe; > > > + return get && uprobe ? get_uprobe(uprobe) : uprobe; > > > > Well, looks "obviously correct". At least the current code is obviously > > wrong, it even checks uprobe != NULL 3 lines above. > > > > Andrii ? > > > > Yes, indeed, I'm more surprised this didn't come up much earlier > (probably it's rare enough to have uretprobe with refcnt at zero > during fork). The fix looks good, thanks! > > Acked-by: Andrii Nakryiko <[email protected]> > > > Acked-by: Oleg Nesterov <[email protected]> > > Thanks, this seems good to me. (uprobe is NULL checked in try_cmpxchg(), so it could be NULL.) Can I pick this to probes/fixes branch? Thank you, -- Masami Hiramatsu (Google) <[email protected]>
