linux/fs
Eric W. Biederman 3151527ee0 userns: Don't allow creation if the user is chrooted
Guarantee that the policy of which files may be access that is
established by setting the root directory will not be violated
by user namespaces by verifying that the root directory points
to the root of the mount namespace at the time of user namespace
creation.

Changing the root is a privileged operation, and as a matter of policy
it serves to limit unprivileged processes to files below the current
root directory.

For reasons of simplicity and comprehensibility the privilege to
change the root directory is gated solely on the CAP_SYS_CHROOT
capability in the user namespace.  Therefore when creating a user
namespace we must ensure that the policy of which files may be access
can not be violated by changing the root directory.

Anyone who runs a processes in a chroot and would like to use user
namespace can setup the same view of filesystems with a mount
namespace instead.  With this result that this is not a practical
limitation for using user namespaces.

Cc: stable@vger.kernel.org
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-27 07:49:29 -07:00
..
9p fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
adfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
affs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
afs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
autofs4 fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
befs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
bfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
btrfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2013-03-17 11:04:14 -07:00
cachefiles
ceph fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
cifs fs: Limit sys_mount to only request filesystem modules. (Part 3) 2013-03-11 07:09:48 -07:00
coda fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
configfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
cramfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
debugfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
devpts fs: Limit sys_mount to only request filesystem modules (Part 2). 2013-03-07 01:08:55 -08:00
dlm hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
ecryptfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2013-03-09 16:51:13 -08:00
efs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
exofs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
exportfs hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
ext2 ext2: Fix BUG_ON in evict() on inode deletion 2013-03-13 15:23:44 +01:00
ext3 ext3: Fix format string issues 2013-03-11 22:05:56 +01:00
ext4 fs: Readd the fs module aliases. 2013-03-12 18:55:21 -07:00
f2fs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
fat fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
freevxfs fs: Readd the fs module aliases. 2013-03-12 18:55:21 -07:00
fscache hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
fuse fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
gfs2 fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
hfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
hfsplus fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
hostfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2013-03-13 15:47:50 -07:00
hpfs fs: Limit sys_mount to only request filesystem modules. (Part 3) 2013-03-11 07:09:48 -07:00
hppfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
hugetlbfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
isofs fs: Readd the fs module aliases. 2013-03-12 18:55:21 -07:00
jbd
jbd2 jbd2: fix ERR_PTR dereference in jbd2__journal_start 2013-03-02 17:08:46 -05:00
jffs2 fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
jfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
lockd Merge branch 'for-3.9' of git://linux-nfs.org/~bfields/linux 2013-02-28 18:02:55 -08:00
logfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
minix fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
ncpfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
nfs fs: Readd the fs module aliases. 2013-03-12 18:55:21 -07:00
nfs_common
nfsd nfsd: convert to idr_alloc() 2013-03-13 15:21:45 -07:00
nilfs2 fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
nls
notify hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
ntfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
ocfs2 fs: Limit sys_mount to only request filesystem modules (Part 2). 2013-03-07 01:08:55 -08:00
omfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
openpromfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
proc proc: Use nd_jump_link in proc_ns_follow_link 2013-03-09 00:14:45 -08:00
pstore A few fixes to reduce places where pstore might hang 2013-02-21 09:38:18 -08:00
qnx4 fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
qnx6 fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
quota quota: add missing use of dq_data_lock in __dquot_initialize 2013-03-11 22:05:56 +01:00
ramfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
reiserfs reiserfs: Use kstrdup instead of kmalloc/strcpy 2013-03-11 22:05:57 +01:00
romfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
squashfs fs: Limit sys_mount to only request filesystem modules. (Part 3) 2013-03-11 07:09:48 -07:00
sysfs hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
sysv fs: Readd the fs module aliases. 2013-03-12 18:55:21 -07:00
ubifs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
udf fs: Limit sys_mount to only request filesystem modules. (Part 3) 2013-03-11 07:09:48 -07:00
ufs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
xfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
Kconfig
Kconfig.binfmt
Makefile
aio.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
anon_inodes.c get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero 2013-02-26 02:46:11 -05:00
attr.c
bad_inode.c
binfmt_aout.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
binfmt_elf.c ImgTec Meta architecture changes for v3.9-rc1 2013-03-03 12:06:09 -08:00
binfmt_elf_fdpic.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
binfmt_em86.c
binfmt_flat.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
binfmt_misc.c fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
binfmt_script.c
binfmt_som.c
bio-integrity.c
bio.c
block_dev.c Merge branch 'for-3.9/core' of git://git.kernel.dk/linux-block 2013-02-28 12:52:24 -08:00
buffer.c Merge branch 'for-3.9/core' of git://git.kernel.dk/linux-block 2013-02-28 12:52:24 -08:00
char_dev.c
compat.c Fix: compat_rw_copy_check_uvector() misuse in aio, readv, writev, and security keys 2013-03-12 11:05:45 -07:00
compat_binfmt_elf.c
compat_ioctl.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
coredump.c coredump: remove redundant defines for dumpable states 2013-02-27 19:10:11 -08:00
coredump.h
dcache.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
dcookies.c
direct-io.c fs: Fix possible use-after-free with AIO 2013-02-22 23:31:36 -05:00
drop_caches.c
eventfd.c
eventpoll.c
exec.c coredump: remove redundant defines for dumpable states 2013-02-27 19:10:11 -08:00
fcntl.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
fhandle.c
fifo.c
file.c locking: Various static lock initializer fixes 2013-02-19 08:42:45 +01:00
file_table.c cache the value of file_inode() in struct file 2013-03-01 19:48:30 -05:00
filesystems.c fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
fs-writeback.c 2 writeback fixes 2013-02-28 13:21:44 -08:00
fs_struct.c constify path_get/path_put and fs_struct.c stuff 2013-03-01 23:51:07 -05:00
generic_acl.c
inode.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
internal.h constify path_get/path_put and fs_struct.c stuff 2013-03-01 23:51:07 -05:00
ioctl.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
ioprio.c
libfs.c
locks.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
mbcache.c
mount.h
mpage.c
namei.c vfs: don't BUG_ON() if following a /proc fd pseudo-symlink results in a symlink 2013-03-08 09:03:07 -08:00
namespace.c userns: Don't allow creation if the user is chrooted 2013-03-27 07:49:29 -07:00
no-block.c
open.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-03-03 13:23:03 -08:00
pipe.c vfs: fix pipe counter breakage 2013-03-12 08:29:17 -07:00
pnode.c
pnode.h
posix_acl.c
proc_namespace.c
read_write.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-03-02 08:34:06 -08:00
read_write.h
readdir.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
select.c
seq_file.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-03-03 13:23:03 -08:00
signalfd.c
splice.c export kernel_write(), convert open-coded instances 2013-02-26 02:46:11 -05:00
stack.c
stat.c switch vfs_getattr() to struct path 2013-02-26 02:46:08 -05:00
statfs.c
super.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
sync.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
timerfd.c compat: restore timerfd settime and gettime compat syscalls 2013-03-02 09:35:13 -05:00
utimes.c
xattr.c
xattr_acl.c