Merge tag 'blackfin-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/realm...

[~andy/linux] / fs / autofs4 / dev-ioctl.c

diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index 1818ce7f5a06049178e968d978733fe29c920e1f..3182c0e68b4204cb2aec089b5d960b7053534757 100644 (file)
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -346,6 +346,7 @@ static int autofs_dev_ioctl_setpipefd(struct file *fp,
 {
        int pipefd;
        int err = 0;
+       struct pid *new_pid = NULL;
 
        if (param->setpipefd.pipefd == -1)
                return -EINVAL;
@@ -357,7 +358,17 @@ static int autofs_dev_ioctl_setpipefd(struct file *fp,
                mutex_unlock(&sbi->wq_mutex);
                return -EBUSY;
        } else {
-               struct file *pipe = fget(pipefd);
+               struct file *pipe;
+
+               new_pid = get_task_pid(current, PIDTYPE_PGID);
+
+               if (ns_of_pid(new_pid) != ns_of_pid(sbi->oz_pgrp)) {
+                       AUTOFS_WARN("Not allowed to change PID namespace");
+                       err = -EINVAL;
+                       goto out;
+               }
+
+               pipe = fget(pipefd);
                if (!pipe) {
                        err = -EBADF;
                        goto out;
@@ -367,12 +378,13 @@ static int autofs_dev_ioctl_setpipefd(struct file *fp,
                        fput(pipe);
                        goto out;
                }
-               sbi->oz_pgrp = task_pgrp_nr(current);
+               swap(sbi->oz_pgrp, new_pid);
                sbi->pipefd = pipefd;
                sbi->pipe = pipe;
                sbi->catatonic = 0;
        }
 out:
+       put_pid(new_pid);
        mutex_unlock(&sbi->wq_mutex);
        return err;
 }