The failure path removes the allocated PIDs from the wrong namespace. This could lead to us inadvertently reusing PIDs in the leaf namespace and leaking PIDs in parent namespaces.

Fixes: 95846ecf9dac ("pid: replace pid bitmap implementation with IDR API") Cc: stable@vger.kernel.org Signed-off-by: Matthew Wilcox willy@infradead.org Acked-by: "Eric W. Biederman" ebiederm@xmission.com Reviewed-by: Oleg Nesterov oleg@redhat.com --- kernel/pid.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/pid.c b/kernel/pid.c index b2f6c506035da..20881598bdfac 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -233,8 +233,10 @@ struct pid *alloc_pid(struct pid_namespace *ns)

out_free: spin_lock_irq(&pidmap_lock); - while (++i <= ns->level) - idr_remove(&ns->idr, (pid->numbers + i)->nr); + while (++i <= ns->level) { + upid = pid->numbers + i; + idr_remove(&upid->ns->idr, upid->nr); + }

/* On failure to allocate the first pid, reset the state */ if (ns->pid_allocated == PIDNS_ADDING)