cred: use correct cred accessor with regards to rcu read lock

Commit "userns: Convert setting and getting uid and gid system calls to use
kuid and kgid has modified the accessors in wait_task_continued() and
wait_task_stopped() to use __task_cred() instead of task_uid().

__task_cred() assumes that we're inside a rcu read lock, which is untrue
for these two functions.

Modify it to use task_uid() instead.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

diff --git a/kernel/exit.c b/kernel/exit.c
index 789e3c5777f7bba0d48fa4950c96fc7e30572e69..910a0716e17ab4124ddd07f22d502e19ed9f30de 100644 (file)
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1427,7 +1427,7 @@ static int wait_task_stopped(struct wait_opts *wo,
        if (!unlikely(wo->wo_flags & WNOWAIT))
                *p_code = 0;
 
-       uid = from_kuid_munged(current_user_ns(), __task_cred(p)->uid);
+       uid = from_kuid_munged(current_user_ns(), task_uid(p));
 unlock_sig:
        spin_unlock_irq(&p->sighand->siglock);
        if (!exit_code)
@@ -1500,7 +1500,7 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
        }
        if (!unlikely(wo->wo_flags & WNOWAIT))
                p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
-       uid = from_kuid_munged(current_user_ns(), __task_cred(p)->uid);
+       uid = from_kuid_munged(current_user_ns(), task_uid(p));
        spin_unlock_irq(&p->sighand->siglock);
 
        pid = task_pid_vnr(p);