linux/fs
Eric Biggers b699b0067c fscrypt: fix race where ->lookup() marks plaintext dentry as ciphertext
commit b01531db6c upstream.

->lookup() in an encrypted directory begins as follows:

1. fscrypt_prepare_lookup():
    a. Try to load the directory's encryption key.
    b. If the key is unavailable, mark the dentry as a ciphertext name
       via d_flags.
2. fscrypt_setup_filename():
    a. Try to load the directory's encryption key.
    b. If the key is available, encrypt the name (treated as a plaintext
       name) to get the on-disk name.  Otherwise decode the name
       (treated as a ciphertext name) to get the on-disk name.

But if the key is concurrently added, it may be found at (2a) but not at
(1a).  In this case, the dentry will be wrongly marked as a ciphertext
name even though it was actually treated as plaintext.

This will cause the dentry to be wrongly invalidated on the next lookup,
potentially causing problems.  For example, if the racy ->lookup() was
part of sys_mount(), then the new mount will be detached when anything
tries to access it.  This is despite the mountpoint having a plaintext
path, which should remain valid now that the key was added.

Of course, this is only possible if there's a userspace race.  Still,
the additional kernel-side race is confusing and unexpected.

Close the kernel-side race by changing fscrypt_prepare_lookup() to also
set the on-disk filename (step 2b), consistent with the d_flags update.

Fixes: 28b4c26396 ("ext4 crypto: revalidate dentry after adding or removing the key")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05 11:08:35 +01:00
..
9p 9p: Fix memory leak in v9fs_mount 2020-08-19 08:15:06 +02:00
adfs fs/adfs: super: fix use-after-free bug 2019-08-06 19:06:49 +02:00
affs affs: fix basic permission bits to actually work 2020-09-09 19:04:30 +02:00
afs afs: Fix NULL deref in afs_dynroot_depopulate() 2020-08-26 10:31:05 +02:00
autofs autofs: fix a leak in autofs_expire_indirect() 2019-12-13 08:51:01 +01:00
befs
bfs bfs: add sanity check at bfs_fill_super() 2018-12-01 09:37:27 +01:00
btrfs btrfs: qgroup: fix data leak caused by race between writeback and truncate 2020-10-01 13:14:49 +02:00
cachefiles cachefiles: Fix race between read_waiter and read_copier involving op->to_do 2020-06-03 08:19:29 +02:00
ceph ceph: fix potential race in ceph_check_caps 2020-10-01 13:14:47 +02:00
cifs cifs: Return the error from crypt_message when enc/dec key not found. 2020-10-29 09:54:59 +01:00
coda coda: add error handling for fget 2019-08-06 19:06:51 +02:00
configfs configfs: fix config_item refcnt leak in configfs_rmdir() 2020-05-27 17:37:32 +02:00
cramfs Cramfs: fix abad comparison when wrap-arounds occur 2018-11-13 11:08:55 -08:00
crypto fscrypt: fix race where ->lookup() marks plaintext dentry as ciphertext 2020-11-05 11:08:35 +01:00
debugfs debugfs: fix use-after-free on symlink traversal 2019-05-08 07:21:48 +02:00
devpts fs/devpts: always delete dcache dentry-s in dput() 2019-03-23 20:09:59 +01:00
dlm fs: dlm: fix configfs memory leak 2020-10-30 10:38:28 +01:00
ecryptfs ecryptfs: replace BUG_ON with error handling code 2020-02-28 16:38:59 +01:00
efivarfs efivarfs: Replace invalid slashes with exclamation marks in dentries. 2020-11-05 11:08:32 +01:00
efs
exofs exofs_mount(): fix leaks on failure exits 2019-12-05 09:20:32 +01:00
exportfs exportfs: fix 'passing zero to ERR_PTR()' warning 2020-01-27 14:50:02 +01:00
ext2 ext2: don't update mtime on COW faults 2020-09-09 19:04:28 +02:00
ext4 fscrypt: fix race where ->lookup() marks plaintext dentry as ciphertext 2020-11-05 11:08:35 +01:00
f2fs fscrypt: fix race where ->lookup() marks plaintext dentry as ciphertext 2020-11-05 11:08:35 +01:00
fat fat: don't allow to mount if the FAT length == 0 2020-06-22 09:05:08 +02:00
freevxfs
fscache fscache: fix race between enablement and dropping of object 2018-12-17 09:24:40 +01:00
fuse fuse: fix page dereference after free 2020-11-05 11:08:34 +01:00
gfs2 gfs2: clean up iopen glock mess in gfs2_create_inode 2020-10-01 13:14:28 +02:00
hfs fs/hfs/extent.c: fix array out of bounds read of array extent 2019-12-01 09:17:10 +01:00
hfsplus hfsplus: fix crash and filesystem corruption when deleting files 2020-04-17 10:48:52 +02:00
hostfs vfs: discard ATTR_ATTR_FLAG 2018-08-17 16:20:28 -07:00
hpfs hpfs: remove unnecessary checks on the value of r when assigning error code 2018-08-25 12:42:33 -07:00
hugetlbfs hugetlb: use same fault hash key for shared and private mappings 2019-05-22 07:37:40 +02:00
isofs isofs: reject hardware sector size > 2048 bytes 2018-08-21 11:37:41 +02:00
jbd2 jbd2: abort journal if free a async write error metadata buffer 2020-09-03 11:24:24 +02:00
jffs2 jffs2: fix UAF problem 2020-08-26 10:31:01 +02:00
jfs jfs: fix bogus variable self-initialization 2020-01-27 14:50:33 +01:00
kernfs kernfs: fix ino wrap-around detection 2019-12-13 08:52:43 +01:00
lockd lockd: fix decoding of TEST results 2019-12-13 08:51:59 +01:00
minix fs/minix: remove expected error message in block_to_path() 2020-08-21 11:05:38 +02:00
nfs nfs: Fix security label length not being reset 2020-10-07 08:00:07 +02:00
nfs_common
nfsd nfsd: Don't add locks to closed or closing open stateids 2020-10-01 13:14:38 +02:00
nilfs2 nilfs2: fix null pointer dereference at nilfs_segctor_do_construct() 2020-06-22 09:05:03 +02:00
nls
notify fanotify: fix ignore mask logic for events on child and on dir 2020-06-30 23:17:00 -04:00
ntfs ntfs: add check for mft record size in superblock 2020-10-30 10:38:28 +01:00
ocfs2 ocfs2: change slot number type s16 to u16 2020-08-21 11:05:33 +02:00
omfs
openpromfs
orangefs help_next should increase position index 2020-02-24 08:34:53 +01:00
overlayfs ovl: fix unneeded call to ovl_change_flags() 2020-07-22 09:32:10 +02:00
proc mm, oom_adj: don't loop through tasks in __set_oom_adj when not necessary 2020-10-29 09:55:15 +01:00
pstore pstore: Fix linking when crypto API disabled 2020-08-19 08:15:04 +02:00
qnx4
qnx6
quota quota: clear padding in v2r1_mem2diskdqb() 2020-10-29 09:55:12 +01:00
ramfs ramfs: fix nommu mmap with gaps in the page cache 2020-10-30 10:38:21 +01:00
reiserfs reiserfs: Fix memory leak in reiserfs_parse_options() 2020-10-30 10:38:31 +01:00
romfs romfs: fix uninitialized memory leak in romfs_dev_read() 2020-08-26 10:30:59 +02:00
squashfs Squashfs: Compute expected length from inode size rather than block length 2018-08-02 09:34:02 -07:00
sysfs Driver core patches for 4.19-rc1 2018-08-18 11:44:53 -07:00
sysv sysv: return 'err' instead of 0 in __sysv_write_inode 2018-12-17 09:24:30 +01:00
tracefs tracefs: Annotate tracefs_ops with __ro_after_init 2018-07-31 11:32:44 -04:00
ubifs fscrypt: fix race where ->lookup() marks plaintext dentry as ciphertext 2020-11-05 11:08:35 +01:00
udf udf: Avoid accessing uninitialized data on failed inode read 2020-10-30 10:38:29 +01:00
ufs fs/ufs: avoid potential u32 multiplication overflow 2020-08-21 11:05:38 +02:00
xfs xfs: make sure the rt allocator doesn't run off the end 2020-10-30 10:38:30 +01:00
aio.c aio: fix async fsync creds 2020-06-22 09:05:01 +02:00
anon_inodes.c anon_inode_getfile(): switch to alloc_file_pseudo() 2018-07-12 10:04:27 -04:00
attr.c fs: Fix attr.c kernel-doc 2018-07-03 16:44:45 -04:00
bad_inode.c get rid of 'opened' argument of ->atomic_open() - part 3 2018-07-12 10:04:20 -04:00
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info() 2020-06-03 08:19:41 +02:00
binfmt_em86.c
binfmt_flat.c fs/binfmt_flat.c: make load_flat_shared_library() work 2019-07-03 13:14:44 +02:00
binfmt_misc.c turn filp_clone_open() into inline wrapper for dentry_open() 2018-07-10 23:29:03 -04:00
binfmt_script.c exec: load_script: Do not exec truncated interpreter path 2019-11-06 13:05:37 +01:00
block_dev.c bdev: Reduce time holding bd_mutex in sync in blkdev_close() 2020-10-01 13:14:42 +02:00
buffer.c fs: prevent BUG_ON in submit_bh_wbc() 2020-09-03 11:24:24 +02:00
char_dev.c chardev: Avoid potential use-after-free in 'chrdev_open()' 2020-01-14 20:06:57 +01:00
compat_binfmt_elf.c
compat_ioctl.c fix compat handling of FICLONERANGE, FIDEDUPERANGE and FS_IOC_FIEMAP 2020-01-09 10:19:07 +01:00
compat.c
coredump.c coredump: fix crash when umh is disabled 2020-05-14 07:57:21 +02:00
d_path.c
dax.c dax: pass NOWAIT flag to iomap_apply 2020-03-05 16:42:12 +01:00
dcache.c fs, fscrypt: clear DCACHE_ENCRYPTED_NAME when unaliasing directory 2020-11-05 11:08:35 +01:00
dcookies.c
direct-io.c direct-io: allow direct writes to empty inodes 2019-03-05 17:58:50 +01:00
drop_caches.c fs: avoid softlockups in s_inodes iterators 2020-01-12 12:17:20 +01:00
eventfd.c eventfd: track eventfd_signal() recursion depth 2020-02-11 04:34:08 -08:00
eventpoll.c ep_create_wakeup_source(): dentry name can change under you... 2020-10-07 08:00:09 +02:00
exec.c exec: Move would_dump into flush_old_exec 2020-05-20 08:18:50 +02:00
fcntl.c signal: Don't send signals to tasks that don't exist 2018-08-15 23:03:20 -05:00
fhandle.c
file_table.c overlayfs update for 4.19 2018-08-21 18:19:09 -07:00
file.c fix multiplication overflow in copy_fdtable() 2020-05-27 17:37:29 +02:00
filesystems.c fs/filesystems.c: downgrade user-reachable WARN_ONCE() to pr_warn_once() 2020-04-17 10:48:51 +02:00
fs_pin.c
fs_struct.c
fs-writeback.c writeback: Fix sync livelock due to b_dirty_time processing 2020-09-03 11:24:28 +02:00
inode.c futex: Fix inode life-time issue 2020-03-25 08:06:14 +01:00
internal.h acct_on(): don't mess with freeze protection 2019-05-31 06:46:05 -07:00
ioctl.c vfs: fix FIGETBSZ ioctl on an overlayfs file 2018-11-21 09:19:14 +01:00
iomap.c iomap: partially revert 4721a60109 (simulated directio short read on EFAULT) 2019-12-13 08:52:56 +01:00
Kconfig
Kconfig.binfmt kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
libfs.c libfs: fix infoleak in simple_attr_read() 2020-04-02 15:28:21 +02:00
locks.c locks: print unsigned ino in /proc/locks 2020-01-09 10:19:00 +01:00
Makefile
mbcache.c
mount.h
mpage.c mpage: mpage_readpages() should submit IO as read-ahead 2018-08-17 16:20:29 -07:00
namei.c namei: only return -ECHILD from follow_dotdot_rcu() 2020-03-05 16:42:20 +01:00
namespace.c fs/namespace.c: fix mountpoint reference counter race 2020-04-29 16:31:26 +02:00
no-block.c
nsfs.c dcache: sort the freeing-without-RCU-delay mess for good. 2019-05-25 18:23:26 +02:00
open.c cifs_atomic_open(): fix double-put on late allocation failure 2020-03-18 07:14:21 +01:00
pipe.c fs: prevent page refcount overflow in pipe_buf_get 2019-05-04 09:20:11 +02:00
pnode.c propagate_one(): mnt_set_mountpoint() needs mount_lock 2020-05-02 17:26:01 +02:00
pnode.h
posix_acl.c
proc_namespace.c
read_write.c vfs: avoid problematic remapping requests into partial EOF block 2019-12-01 09:17:04 +01:00
readdir.c filldir[64]: remove WARN_ON_ONCE() for bad directory entries 2020-01-04 19:13:26 +01:00
select.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
seq_file.c seq_file: fix problem when seeking mid-record 2019-08-25 10:47:43 +02:00
signalfd.c fs/signalfd.c: fix inconsistent return codes for signalfd4 2020-08-26 10:31:02 +02:00
splice.c splice: only read in as much information as there is pipe buffer space 2019-12-17 20:35:43 +01:00
stack.c
stat.c
statfs.c vfs: Fix EOVERFLOW testing in put_compat_statfs64 2019-10-11 18:21:39 +02:00
super.c Merge branch 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax 2018-08-26 11:48:42 -07:00
sync.c
timerfd.c Merge branch 'work.aio' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-08-13 20:56:23 -07:00
userfaultfd.c userfaultfd: require CAP_SYS_PTRACE for UFFD_FEATURE_EVENT_FORK 2020-01-04 19:13:18 +01:00
utimes.c
xattr.c xattr: break delegations in {set,remove}xattr 2020-08-11 15:32:34 +02:00