From d0aed5c2b40ad7226b025c36d238e437a98f1162 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 2 Apr 2014 17:45:05 +0200 Subject: pid_namespace: pidns_get() should check task_active_pid_ns() != NULL commit d23082257d83e4bc89727d5aedee197e907999d2 upstream. 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> Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- kernel/pid_namespace.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index 06c62de9c71..db95d8eb761 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; -- cgit v1.2.3-18-g5258