From: Corey Minyard cminyard@mvista.com

Recent changes to alloc_pid() allow the pid number to be specified on the command line. If set_tid_size is set, then the code scanning the levels will hard-set retval to -EPERM, overriding it's previous -ENOMEM value.

After the code scanning the levels, there are error returns that do not set retval, assuming it is still set to -ENOMEM.

So set retval back to -ENOMEM after scanning the levels.

Fixes: 49cb2fc42ce4 "fork: extend clone3() to support setting a PID" Signed-off-by: Corey Minyard cminyard@mvista.com Cc: stable@vger.kernel.org # 5.5 Cc: Adrian Reber areber@redhat.com Cc: Christian Brauner christian.brauner@ubuntu.com Cc: Oleg Nesterov oleg@redhat.com Cc: Dmitry Safonov 0x7f454c46@gmail.com Cc: Andrei Vagin avagin@gmail.com ---

Changes from v1: Just set retval to -ENOMEM before the gotos that would use it.

I do think that the second instance:

if (!(ns->pid_allocated & PIDNS_ADDING)) goto out_unlock;

is returning the wrong error value, but that's probably not a big deal, and if it was fixed would probably need to be a separate change.

In the first instance, the error return values are almost all -ENOMEM, anyway.

kernel/pid.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/kernel/pid.c b/kernel/pid.c index 0f4ecb57214c..19645b25b77c 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -247,6 +247,8 @@ struct pid *alloc_pid(struct pid_namespace *ns, pid_t *set_tid, tmp = tmp->parent; }

+ retval = -ENOMEM; + if (unlikely(is_child_reaper(pid))) { if (pid_ns_prepare_proc(ns)) goto out_free;