cred: use correct cred accessor with regards to rcu read lock (8ca937a6) · Commits · 戴 / test

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>

kernel/exit.c

+2 −2

Original line number	Original line	Diff line number	Diff line
	@@ -1427,7 +1427,7 @@ static int wait_task_stopped(struct wait_opts *wo,
	if (!unlikely(wo->wo_flags & WNOWAIT))		if (!unlikely(wo->wo_flags & WNOWAIT))
	*p_code = 0;		*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:		unlock_sig:
	spin_unlock_irq(&p->sighand->siglock);		spin_unlock_irq(&p->sighand->siglock);
	if (!exit_code)		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))		if (!unlikely(wo->wo_flags & WNOWAIT))
	p->signal->flags &= ~SIGNAL_STOP_CONTINUED;		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);		spin_unlock_irq(&p->sighand->siglock);

	pid = task_pid_vnr(p);		pid = task_pid_vnr(p);

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