linux/fs
Al Viro bcf0d9d4b7 ecryptfs: fix unlink and rmdir in face of underlying fs modifications
A problem similar to the one caught in commit 74dd7c97ea ("ecryptfs_rename():
verify that lower dentries are still OK after lock_rename()") exists for
unlink/rmdir as well.

Instead of playing with dget_parent() of underlying dentry of victim
and hoping it's the same as underlying dentry of our directory,
do the following:
        * find the underlying dentry of victim
        * find the underlying directory of victim's parent (stable
since the victim is ecryptfs dentry and inode of its parent is
held exclusive by the caller).
        * lock the inode of dentry underlying the victim's parent
        * check that underlying dentry of victim is still hashed and
has the right parent - it can be moved, but it can't be moved to/from
the directory we are holding exclusive.  So while ->d_parent itself
might not be stable, the result of comparison is.

If the check passes, everything is fine - underlying directory is locked,
underlying victim is still a child of that directory and we can go ahead
and feed them to vfs_unlink().  As in the current mainline we need to
pin the underlying dentry of victim, so that it wouldn't go negative under
us, but that's the only temporary reference that needs to be grabbed there.
Underlying dentry of parent won't go away (it's pinned by the parent,
which is held by caller), so there's no need to grab it.

The same problem (with the same solution) exists for rmdir.  Moreover,
rename gets simpler and more robust with the same "don't bother with
dget_parent()" approach.

Fixes: 74dd7c97ea "ecryptfs_rename(): verify that lower dentries are still OK after lock_rename()"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-11-10 11:57:44 -05:00
..
9p 9p pull request for inclusion in 5.4 2019-09-27 15:10:34 -07:00
adfs Merge branch 'work.adfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 11:33:22 -07:00
affs fs: affs: Initialize filesystem timestamp ranges 2019-08-30 07:27:18 -07:00
afs Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-09-29 19:42:07 -07:00
autofs autofs: fix a leak in autofs_expire_indirect() 2019-10-25 00:03:11 -04:00
befs fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
bfs fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
btrfs for-5.4-rc2-tag 2019-10-10 08:30:51 -07:00
cachefiles treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
ceph The highlights are: 2019-09-25 10:21:13 -07:00
cifs CIFS: Force reval dentry if LOOKUP_REVAL flag is set 2019-10-09 00:10:50 -05:00
coda y2038: add inode timestamp clamping 2019-09-19 09:42:37 -07:00
configfs configfs updates for 5.4: 2019-09-19 13:09:28 -07:00
cramfs Merge branch 'work.mount2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-09-19 10:06:57 -07:00
crypto fscrypt: require that key be added when setting a v2 encryption policy 2019-08-12 19:18:50 -07:00
debugfs Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
devpts devpts_pty_kill(): don't bother with d_delete() 2019-09-03 09:30:56 -04:00
dlm dlm for 5.3 2019-07-12 17:37:53 -07:00
ecryptfs ecryptfs: fix unlink and rmdir in face of underlying fs modifications 2019-11-10 11:57:44 -05:00
efivarfs Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
efs fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
erofs erofs: fix mis-inplace determination related with noio chain 2019-10-01 04:54:45 +08:00
exportfs exportfs_decode_fh(): negative pinned may become positive without the parent locked 2019-11-10 11:56:05 -05:00
ext2 \n 2019-09-21 13:53:34 -07:00
ext4 Merge branch 'entropy' 2019-09-29 19:25:39 -07:00
f2fs f2fs-for-5.4-rc1 2019-09-21 14:26:33 -07:00
fat fat: delete an unnecessary check before brelse() 2019-09-25 17:51:40 -07:00
freevxfs fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
fscache Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
fuse add virtio-fs 2019-09-27 15:54:24 -07:00
gfs2 Merge branch 'work.mount3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-09-24 12:33:34 -07:00
hfs treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
hfsplus fs/hfsplus/xattr.c: replace strncpy with memcpy 2019-07-16 19:23:23 -07:00
hostfs This pull request contains the following changes for UML: 2019-05-12 17:52:13 -04:00
hpfs fs: hpfs: Initialize filesystem timestamp ranges 2019-08-30 08:11:25 -07:00
hugetlbfs Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
iomap iomap: move the iomap_dio_rw ->end_io callback into a structure 2019-09-19 15:32:45 -07:00
isofs y2038: add inode timestamp clamping 2019-09-19 09:42:37 -07:00
jbd2 jbd2: remove jbd2_journal_inode_add_[write|wait] 2019-09-24 15:54:07 -07:00
jffs2 Merge branch 'work.mount3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-09-26 11:33:30 -07:00
jfs y2038: add inode timestamp clamping 2019-09-19 09:42:37 -07:00
kernfs y2038: add inode timestamp clamping 2019-09-19 09:42:37 -07:00
lockd lockd: Make two symbols static 2019-07-03 17:52:09 -04:00
minix fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
nfs NFSv4: Fix leak of clp->cl_acceptor string 2019-10-10 16:14:02 -04:00
nfs_common treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
nfsd Highlights: 2019-09-27 17:00:27 -07:00
nilfs2 vfs: create a generic checking and prep function for FS_IOC_SETFLAGS 2019-07-01 08:25:34 -07:00
nls treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
notify Highlights: 2019-09-27 17:00:27 -07:00
ntfs ntfs: remove (un)?likely() from IS_ERR() conditions 2019-09-26 10:10:44 -07:00
ocfs2 fs: ocfs2: fix a possible null-pointer dereference in ocfs2_info_scan_inode_alloc() 2019-10-07 15:47:19 -07:00
omfs fs: omfs: Initialize filesystem timestamp ranges 2019-08-30 08:11:25 -07:00
openpromfs Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
orangefs Orangefs: a fix and a cleanup 2019-09-19 10:21:35 -07:00
overlayfs ovl: filter of trusted xattr results in audit 2019-09-11 16:11:45 +02:00
proc Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
pstore pstore: fs superblock limits 2019-08-30 08:11:25 -07:00
qnx4 fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
qnx6 fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
quota quota: fix condition for resetting time limit in do_set_dqblk() 2019-07-31 12:04:42 +02:00
ramfs vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API 2019-09-12 21:05:34 -04:00
reiserfs fs/reiserfs/do_balan.c: remove set but not used variable 2019-09-25 17:51:40 -07:00
romfs Merge branch 'work.mount2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-09-19 10:06:57 -07:00
squashfs Merge branch 'work.mount2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-09-19 10:06:57 -07:00
sysfs Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
sysv fs: sysv: Initialize filesystem timestamp ranges 2019-08-30 07:27:18 -07:00
tracefs tracing: Do not create tracefs files if tracefs lockdown is in effect 2019-10-12 20:49:07 -04:00
ubifs This pull request contains the following changes for UBI, UBIFS and JFFS2: 2019-09-21 11:10:16 -07:00
udf fs-udf: Delete an unnecessary check before brelse() 2019-09-04 18:19:43 +02:00
ufs y2038: add inode timestamp clamping 2019-09-19 09:42:37 -07:00
unicode unicode: make array 'token' static const, makes object smaller 2019-09-17 11:48:24 -04:00
verity fs-verity: support builtin file signatures 2019-08-12 19:33:50 -07:00
xfs xfs: move local to extent inode logging into bmap helper 2019-10-09 08:54:30 -07:00
aio.c aio: Fix io_pgetevents() struct __compat_aio_sigset layout 2019-10-21 19:12:19 -04:00
anon_inodes.c Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
attr.c timestamp_truncate: Replace users of timespec64_trunc 2019-08-30 07:27:17 -07:00
bad_inode.c
binfmt_aout.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
binfmt_elf_fdpic.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
binfmt_elf.c elf: don't use MAP_FIXED_NOREPLACE for elf executable mappings 2019-10-06 13:53:27 -07:00
binfmt_em86.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
binfmt_flat.c fs/binfmt_flat.c: remove set but not used variable 'inode' 2019-07-16 19:23:22 -07:00
binfmt_misc.c Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
binfmt_script.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
block_dev.c Changes for 5.4: 2019-09-18 17:35:20 -07:00
buffer.c for-linus-20190715 2019-07-15 21:20:52 -07:00
char_dev.c chardev: set variable ret to -EBUSY before checking minor range overlap 2019-05-24 20:50:36 +02:00
compat_binfmt_elf.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193 2019-05-30 11:29:21 -07:00
compat_ioctl.c compat_ioctl: pppoe: fix PPPOEIOCSFWD handling 2019-07-30 14:42:13 -07:00
compat.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
coredump.c coredump: split pipe command whitespace before expanding template 2019-08-03 07:02:01 -07:00
d_path.c [PATCH] fix d_absolute_path() interplay with fsmount() 2019-08-30 19:31:09 -04:00
dax.c dax: dax_layout_busy_page() should not unmap cow pages 2019-08-05 14:59:05 -07:00
dcache.c Merge branch 'work.dcache2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-20 09:15:51 -07:00
dcookies.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
direct-io.c direct-io: use bio_release_pages in dio_bio_complete 2019-06-29 09:47:31 -06:00
drop_caches.c
eventfd.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
eventpoll.c PM / wakeup: Show wakeup sources stats in sysfs 2019-08-21 00:20:40 +02:00
exec.c sched/membarrier: Fix p->mm->membarrier_state racy load 2019-09-25 17:42:30 +02:00
fcntl.c
fhandle.c fs/handle.c - fix up kerneldoc 2019-08-07 21:51:47 -04:00
file_table.c vfs: Export flush_delayed_fput for use by knfsd. 2019-08-19 11:00:39 -04:00
file.c
filesystems.c
fs_context.c vfs: subtype handling moved to fuse 2019-09-06 21:28:49 +02:00
fs_parser.c vfs: Make fs_parse() handle fs_param_is_fd-type params better 2019-09-12 21:06:14 -04:00
fs_pin.c switch the remnants of releasing the mountpoint away from fs_pin 2019-07-16 22:52:37 -04:00
fs_struct.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
fs_types.c
fs-writeback.c writeback: fix use-after-free in finish_writeback_work() 2019-10-07 15:47:19 -07:00
fsopen.c Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
inode.c mm,thp: avoid writes to file with THP in pagecache 2019-09-24 15:54:11 -07:00
internal.h Merge branch 'work.dcache2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-20 09:15:51 -07:00
io_uring.c for-linus-20191012 2019-10-13 08:15:35 -07:00
ioctl.c
Kconfig fs-verity for 5.4 2019-09-18 16:59:14 -07:00
Kconfig.binfmt binfmt_flat: make support for old format binaries optional 2019-06-24 09:16:47 +10:00
libfs.c libfs: take cursors out of list when moving past the end of directory 2019-10-09 22:57:30 -04:00
locks.c Highlights: 2019-09-27 17:00:27 -07:00
Makefile fs-verity for 5.4 2019-09-18 16:59:14 -07:00
mbcache.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
mount.h switch the remnants of releasing the mountpoint away from fs_pin 2019-07-16 22:52:37 -04:00
mpage.c blkcg, writeback: Rename wbc_account_io() to wbc_account_cgroup_owner() 2019-07-10 09:00:57 -06:00
namei.c fs/namei.c: keep track of nd->root refcount status 2019-09-03 09:30:45 -04:00
namespace.c fs/namespace.c: fix use-after-free of mount in mnt_warn_timestamp_expiry() 2019-10-16 23:15:09 -04:00
no-block.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
nsfs.c vfs: Convert nsfs to use the new mount API 2019-05-25 18:00:06 -04:00
open.c fs: remove unlikely() from WARN_ON() condition 2019-09-26 10:10:30 -07:00
pipe.c vfs: Convert pipe to use the new mount API 2019-05-25 18:00:07 -04:00
pnode.c fs/namespace: fix unprivileged mount propagation 2019-06-17 17:36:09 -04:00
pnode.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 209 2019-05-30 11:29:53 -07:00
posix_acl.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
proc_namespace.c vfs: subtype handling moved to fuse 2019-09-06 21:28:49 +02:00
read_write.c vfs: fix page locking deadlocks when deduping files 2019-08-16 18:43:24 -07:00
readdir.c uaccess: implement a proper unsafe_copy_to_user() and switch filldir over to it 2019-10-07 12:56:48 -07:00
select.c fs/select.c: use struct_size() in kmalloc() 2019-07-16 19:23:25 -07:00
seq_file.c seq_file: fix problem when seeking mid-record 2019-08-13 16:06:52 -07:00
signalfd.c
splice.c uio: make import_iovec()/compat_import_iovec() return bytes on success 2019-05-31 15:30:03 -06:00
stack.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
stat.c
statfs.c vfs: Fix EOVERFLOW testing in put_compat_statfs64 2019-10-03 14:21:35 -07:00
super.c Merge branch 'work.mount3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-10-10 08:16:44 -07:00
sync.c fs/sync.c: sync_file_range(2) may use WB_SYNC_ALL writeback 2019-05-14 09:47:50 -07:00
timerfd.c timerfd: Prepare for PREEMPT_RT 2019-08-01 20:51:23 +02:00
userfaultfd.c userfaultfd: untag user pointers 2019-09-25 17:51:41 -07:00
utimes.c utimes: Clamp the timestamps before update 2019-08-30 07:27:17 -07:00
xattr.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00