Merge branch 'akpm' (incoming from Andrew)

Merge second patch-bomb from Andrew Morton:
 - various misc bits
 - the rest of MM
 - add generic fixmap.h, use it
 - backlight updates
 - dynamic_debug updates
 - printk() updates
 - checkpatch updates
 - binfmt_elf
 - ramfs
 - init/
 - autofs4
 - drivers/rtc
 - nilfs
 - hfsplus
 - Documentation/
 - coredump
 - procfs
 - fork
 - exec
 - kexec
 - kdump
 - partitions
 - rapidio
 - rbtree
 - userns
 - memstick
 - w1
 - decompressors

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (197 commits)
  lib/decompress_unlz4.c: always set an error return code on failures
  romfs: fix returm err while getting inode in fill_super
  drivers/w1/masters/w1-gpio.c: add strong pullup emulation
  drivers/memstick/host/rtsx_pci_ms.c: fix ms card data transfer bug
  userns: relax the posix_acl_valid() checks
  arch/sh/kernel/dwarf.c: use rbtree postorder iteration helper instead of solution using repeated rb_erase()
  fs-ext3-use-rbtree-postorder-iteration-helper-instead-of-opencoding-fix
  fs/ext3: use rbtree postorder iteration helper instead of opencoding
  fs/jffs2: use rbtree postorder iteration helper instead of opencoding
  fs/ext4: use rbtree postorder iteration helper instead of opencoding
  fs/ubifs: use rbtree postorder iteration helper instead of opencoding
  net/netfilter/ipset/ip_set_hash_netiface.c: use rbtree postorder iteration instead of opencoding
  rbtree/test: test rbtree_postorder_for_each_entry_safe()
  rbtree/test: move rb_node to the middle of the test struct
  rapidio: add modular rapidio core build into powerpc and mips branches
  partitions/efi: complete documentation of gpt kernel param purpose
  kdump: add /sys/kernel/vmcoreinfo ABI documentation
  kdump: fix exported size of vmcoreinfo note
  kexec: add sysctl to disable kexec_load
  fs/exec.c: call arch_pick_mmap_layout() only once
  ...

1 files changed, 14 insertions, 2 deletions

diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index 1818ce7f5a06..3182c0e68b42 100644
--- 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;
 }