From: Oleg Nesterov Date: Wed, 2 Apr 2014 15:45:05 +0000 (+0200) Subject: pid_namespace: pidns_get() should check task_active_pid_ns() != NULL X-Git-Tag: v4.14-rc1~7789 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d23082257d83e4bc89727d5aedee197e907999d2;p=platform%2Fkernel%2Flinux-rpi.git pid_namespace: pidns_get() should check task_active_pid_ns() != NULL pidns_get()->get_pid_ns() can hit ns == NULL. This task_struct can't go away, but task_active_pid_ns(task) is NULL if release_task(task) was already called. Alternatively we could change get_pid_ns(ns) to check ns != NULL, but it seems that other callers are fine. Signed-off-by: Oleg Nesterov Cc: Eric W. Biederman ebiederm@xmission.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds --- diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index 06c62de..db95d8e 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -318,7 +318,9 @@ static void *pidns_get(struct task_struct *task) struct pid_namespace *ns; rcu_read_lock(); - ns = get_pid_ns(task_active_pid_ns(task)); + ns = task_active_pid_ns(task); + if (ns) + get_pid_ns(ns); rcu_read_unlock(); return ns;