linux/fs
Eric W. Biederman 0d0826019e mnt: Prevent pivot_root from creating a loop in the mount tree
Andy Lutomirski recently demonstrated that when chroot is used to set
the root path below the path for the new ``root'' passed to pivot_root
the pivot_root system call succeeds and leaks mounts.

In examining the code I see that starting with a new root that is
below the current root in the mount tree will result in a loop in the
mount tree after the mounts are detached and then reattached to one
another.  Resulting in all kinds of ugliness including a leak of that
mounts involved in the leak of the mount loop.

Prevent this problem by ensuring that the new mount is reachable from
the current root of the mount tree.

[Added stable cc.  Fixes CVE-2014-7970.  --Andy]

Cc: stable@vger.kernel.org
Reported-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/87bnpmihks.fsf@x220.int.ebiederm.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
2014-10-14 14:27:19 -07:00
..
9p Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-06-12 10:30:18 -07:00
adfs adfs: add __printf verification, fix format/argument mismatches 2014-08-08 15:57:24 -07:00
affs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-06-12 10:30:18 -07:00
afs AFS: Correctly assemble the client UUID 2014-07-29 10:14:36 -07:00
autofs4 autofs4: comment typo: remove a a doubled word 2014-08-08 15:57:19 -07:00
befs fs/befs/linuxvfs.c: check superblock before dump operation 2014-08-08 15:57:20 -07:00
bfs fs/bfs: use bfs prefix for dump_imap 2014-08-08 15:57:24 -07:00
btrfs Merge branch 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-10 07:26:02 -04:00
cachefiles fs/cachefiles: add missing \n to kerror conversions 2014-09-26 08:10:35 -07:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2014-08-13 17:43:29 -06:00
cifs CIFS: Fix readpages retrying on reconnects 2014-10-02 14:17:41 -05:00
coda fs/coda: use linux/uaccess.h 2014-08-08 15:57:20 -07:00
configfs fs/configfs: use pr_fmt 2014-06-04 16:53:53 -07:00
cramfs fs/cramfs/inode.c: use linux/uaccess.h 2014-08-08 15:57:25 -07:00
debugfs fs: debugfs: remove trailing whitespace 2014-07-09 16:58:21 -07:00
devpts fs/devpts/inode.c: convert printk to pr_foo() 2014-06-06 16:08:14 -07:00
dlm fs/dlm/debug_fs.c: remove unnecessary null test before debugfs_remove 2014-08-08 15:57:27 -07:00
ecryptfs write_iter variants of {__,}generic_file_aio_write() 2014-05-06 17:38:00 -04:00
efivarfs fs/efivarfs/super.c: use static const for dentry_operations 2014-06-04 16:54:14 -07:00
efs fs/efs/namei.c: return is not a function 2014-08-08 15:57:18 -07:00
exofs fs/exofs/ore_raid.c: replace count*size kzalloc by kcalloc 2014-08-08 15:57:24 -07:00
exportfs fs/exportfs/expfs.c: kernel-doc warning fixes 2014-06-04 16:54:14 -07:00
ext2 percpu_counter: add @gfp to percpu_counter_init() 2014-09-08 09:51:29 +09:00
ext3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block into for-3.18 2014-09-24 13:00:21 -04:00
ext4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block into for-3.18 2014-09-24 13:00:21 -04:00
f2fs f2fs: support volatile operations for transient data 2014-10-07 11:54:41 -07:00
fat Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-06-12 10:30:18 -07:00
freevxfs Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
fscache FS-Cache: refcount becomes corrupt under vma pressure. 2014-09-17 22:41:40 +01:00
fuse fuse: honour max_read and max_write in direct_io mode 2014-09-26 21:16:51 -04:00
gfs2 GFS2: fix d_splice_alias() misuses 2014-09-12 20:58:55 +01:00
hfs write_iter variants of {__,}generic_file_aio_write() 2014-05-06 17:38:00 -04:00
hfsplus Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-06-12 10:30:18 -07:00
hostfs hostfs: support rename flags 2014-08-07 14:40:09 -04:00
hpfs fs/hpfs/dnode.c: fix suspect code indent 2014-08-08 15:57:22 -07:00
hppfs
hugetlbfs fs/hugetlbfs/inode.c: remove null test before kfree 2014-06-04 16:54:11 -07:00
isofs isofs: Fix unbounded recursion when processing relocated directories 2014-08-19 18:29:30 +02:00
jbd fs/jbd/revoke.c: replace shift loop by ilog2 2014-05-21 10:26:13 +02:00
jbd2 jbd2: fix descriptor block size handling errors with journal_csum 2014-08-28 22:22:29 -04:00
jffs2 MTD updates for 3.17-rc1 2014-08-08 18:13:21 -07:00
jfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-06-12 10:30:18 -07:00
kernfs Merge 3.16-rc6 into driver-core-next 2014-07-21 10:07:25 -07:00
lockd Merge branch 'for-3.18' of git://linux-nfs.org/~bfields/linux 2014-10-08 12:51:44 -04:00
logfs fs/logfs/readwrite.c: kernel-doc warning fixes 2014-08-06 18:01:12 -07:00
minix minix zmap block counts calculation fix 2014-08-08 15:57:20 -07:00
ncpfs fs/ncpfs/getopt.c: replace simple_strtoul by kstrtoul 2014-06-04 16:54:21 -07:00
nfs Merge branch 'for-3.18' of git://linux-nfs.org/~bfields/linux 2014-10-08 12:51:44 -04:00
nfs_common lockd: move lockd's grace period handling into its own module 2014-09-17 16:33:11 -04:00
nfsd Merge branch 'for-3.18' of git://linux-nfs.org/~bfields/linux 2014-10-08 12:51:44 -04:00
nilfs2 nilfs2: fix data loss with mmap() 2014-09-26 08:10:34 -07:00
nls
notify fanotify: enable close-on-exec on events' fd when requested in fanotify_init() 2014-10-09 22:25:46 -04:00
ntfs ntfs: remove bogus space 2014-10-09 22:25:46 -04:00
ocfs2 ocfs2: fix a deadlock while o2net_wq doing direct memory reclaim 2014-10-09 22:25:58 -04:00
omfs fs/omfs/inode.c: replace count*size kzalloc by kcalloc 2014-08-08 15:57:25 -07:00
openpromfs
proc Merge branch 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2014-10-10 07:24:40 -04:00
pstore fs/pstore/ram_core.c: replace count*size kmalloc by kmalloc_array 2014-08-08 15:57:25 -07:00
qnx4
qnx6 fs/qnx6: update debugging to current functions 2014-08-08 15:57:26 -07:00
quota percpu_counter: add @gfp to percpu_counter_init() 2014-09-08 09:51:29 +09:00
ramfs fs/ramfs/file-nommu.c: replace count*size kzalloc by kcalloc 2014-08-08 15:57:18 -07:00
reiserfs Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2014-08-13 17:45:40 -06:00
romfs fs/romfs/super.c: add blank line after declarations 2014-08-08 15:57:25 -07:00
squashfs fs/squashfs/super.c: logging cleanup 2014-08-06 18:01:13 -07:00
sysfs kernfs: move the last knowledge of sysfs out from kernfs 2014-06-03 08:11:18 -07:00
sysv write_iter variants of {__,}generic_file_aio_write() 2014-05-06 17:38:00 -04:00
ubifs UBIFS: Add log overlap assertions 2014-07-31 15:52:51 +03:00
udf udf: saner calling conventions for udf_new_inode() 2014-09-04 21:37:41 +02:00
ufs ufs: deal with nfsd/iget races 2014-09-26 21:17:52 -04:00
xfs xfs: trim eofblocks before collapse range 2014-09-02 12:12:53 +10:00
aio.c percpu_ref: add PERCPU_REF_INIT_* flags 2014-09-24 13:31:50 -04:00
anon_inodes.c
attr.c fs,userns: Change inode_capable to capable_wrt_inode_uidgid 2014-06-10 13:57:22 -07:00
bad_inode.c bad_inode: add ->rename2() 2014-08-07 14:40:09 -04:00
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c Merge branch 'x86/vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next 2014-06-05 08:05:29 -07:00
binfmt_em86.c
binfmt_flat.c fs/binfmt_flat.c: make old_reloc() static 2014-06-04 16:54:21 -07:00
binfmt_misc.c binfmt_misc: add missing 'break' statement 2014-04-03 16:21:16 -07:00
binfmt_script.c
binfmt_som.c
block_dev.c block_dev: implement readpages() to optimize sequential read 2014-10-09 22:25:53 -04:00
buffer.c fs/buffer.c: increase the buffer-head per-CPU LRU size 2014-10-09 22:26:02 -04:00
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c Bluetooth: Move HCI socket definitions into its own header file 2014-07-11 13:53:04 +03:00
compat.c locks: rename file-private locks to "open file description locks" 2014-04-22 08:23:58 -04:00
coredump.c coredump: fix the setting of PF_DUMPCORE 2014-07-23 15:10:54 -07:00
dcache.c vfs: Don't exchange "short" filenames unconditionally. 2014-09-27 15:59:39 -04:00
dcookies.c
direct-io.c fuse: honour max_read and max_write in direct_io mode 2014-09-26 21:16:51 -04:00
drop_caches.c fs: convert use of typedef ctl_table to struct ctl_table 2014-06-06 16:08:16 -07:00
eventfd.c
eventpoll.c eventpoll: fix uninitialized variable in epoll_ctl 2014-09-10 15:42:12 -07:00
exec.c fork/exec: cleanup mm initialization 2014-08-08 15:57:23 -07:00
fcntl.c shm: add sealing API 2014-08-08 15:57:31 -07:00
fhandle.c
file_table.c percpu_counter: add @gfp to percpu_counter_init() 2014-09-08 09:51:29 +09:00
file.c fs/file.c: don't open-code kvfree() 2014-05-06 17:31:10 -04:00
filesystems.c sys_sysfs: Add CONFIG_SYSFS_SYSCALL 2014-04-03 16:21:05 -07:00
fs_pin.c make fs/{namespace,super}.c forget about acct.h 2014-08-07 14:40:09 -04:00
fs_struct.c
fs-writeback.c sched: Remove proliferation of wait_on_bit() action functions 2014-07-16 15:10:39 +02:00
inode.c mm: allow drivers to prevent new writable mappings 2014-08-08 15:57:31 -07:00
internal.h vfs: guard end of device for mpage interface 2014-10-09 22:25:53 -04:00
ioctl.c
Kconfig lockd: move lockd's grace period handling into its own module 2014-09-17 16:33:11 -04:00
Kconfig.binfmt
libfs.c fs/libfs.c: add generic data flush to fsync 2014-06-04 16:53:55 -07:00
locks.c locks: pass correct "before" pointer to locks_unlink_lock in generic_add_lease 2014-08-22 09:58:22 -04:00
Makefile take fs_pin stuff to fs/* 2014-08-07 14:40:08 -04:00
mbcache.c fs/mbcache: replace __builtin_log2() with ilog2() 2014-06-25 22:08:29 -04:00
mount.h death to mnt_pinned 2014-08-07 14:40:09 -04:00
mpage.c vfs: guard end of device for mpage interface 2014-10-09 22:25:53 -04:00
namei.c vfs: workaround gcc <4.6 build error in link_path_walk() 2014-09-16 07:44:54 -07:00
namespace.c mnt: Prevent pivot_root from creating a loop in the mount tree 2014-10-14 14:27:19 -07:00
no-block.c
open.c vfs: fix check for fallocate on active swapfile 2014-08-01 02:36:04 -04:00
pipe.c new helper: copy_page_from_iter() 2014-05-06 17:39:42 -04:00
pnode.c get rid of propagate_umount() mistakenly treating slaves as busy. 2014-08-30 18:31:41 -04:00
pnode.h
posix_acl.c posix_acl: handle NULL ACL in posix_acl_equiv_mode 2014-05-06 13:58:42 -04:00
proc_namespace.c namespaces: Use task_lock and not rcu to protect nsproxy 2014-07-29 18:08:50 -07:00
read_write.c switch simple generic_file_aio_read() users to ->read_iter() 2014-05-06 17:37:55 -04:00
readdir.c fanotify: create FAN_ACCESS event for readdir 2014-06-04 16:53:52 -07:00
select.c
seq_file.c fs/seq_file: fallback to vmalloc allocation 2014-07-03 09:21:54 -07:00
signalfd.c
splice.c Merge commit '9f12600fe425bc28f0ccba034a77783c09c15af4' into for-linus 2014-06-12 00:28:09 -04:00
stack.c fs: fix comment for 'CONFIG_LBADF' 2014-08-26 09:35:56 +02:00
stat.c
statfs.c
super.c percpu_counter: add @gfp to percpu_counter_init() 2014-09-08 09:51:29 +09:00
sync.c Export sync_filesystem() for modular ->remount_fs() use 2014-09-05 08:16:21 -07:00
timerfd.c timerfd: Remove an always true check 2014-08-27 11:17:48 +02:00
utimes.c
xattr.c simple_xattr: permit 0-size extended attributes 2014-07-23 15:10:55 -07:00