linux-stable/fs
Daniel Rosenberg edc440e3d2 fscrypt: improve format of no-key names
When an encrypted directory is listed without the key, the filesystem
must show "no-key names" that uniquely identify directory entries, are
at most 255 (NAME_MAX) bytes long, and don't contain '/' or '\0'.
Currently, for short names the no-key name is the base64 encoding of the
ciphertext filename, while for long names it's the base64 encoding of
the ciphertext filename's dirhash and second-to-last 16-byte block.

This format has the following problems:

- Since it doesn't always include the dirhash, it's incompatible with
  directories that will use a secret-keyed dirhash over the plaintext
  filenames.  In this case, the dirhash won't be computable from the
  ciphertext name without the key, so it instead must be retrieved from
  the directory entry and always included in the no-key name.
  Casefolded encrypted directories will use this type of dirhash.

- It's ambiguous: it's possible to craft two filenames that map to the
  same no-key name, since the method used to abbreviate long filenames
  doesn't use a proper cryptographic hash function.

Solve both these problems by switching to a new no-key name format that
is the base64 encoding of a variable-length structure that contains the
dirhash, up to 149 bytes of the ciphertext filename, and (if any bytes
remain) the SHA-256 of the remaining bytes of the ciphertext filename.

This ensures that each no-key name contains everything needed to find
the directory entry again, contains only legal characters, doesn't
exceed NAME_MAX, is unambiguous unless there's a SHA-256 collision, and
that we only take the performance hit of SHA-256 on very long filenames.

Note: this change does *not* address the existing issue where users can
modify the 'dirhash' part of a no-key name and the filesystem may still
accept the name.

Signed-off-by: Daniel Rosenberg <drosen@google.com>
[EB: improved comments and commit message, fixed checking return value
 of base64_decode(), check for SHA-256 error, continue to set disk_name
 for short names to keep matching simpler, and many other cleanups]
Link: https://lore.kernel.org/r/20200120223201.241390-7-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
2020-01-22 14:50:03 -08:00
..
9p 9p pull request for inclusion in 5.4 2019-09-27 15:10:34 -07:00
adfs
affs affs: fix a memory leak in affs_remount 2019-11-18 14:26:43 +01:00
afs afs: Show volume name in /proc/net/afs/<cell>/volumes 2019-12-11 17:48:20 +00:00
autofs Merge branch 'next.autofs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-12-05 17:11:48 -08:00
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-5.5-rc2-tag 2019-12-17 13:27:02 -08:00
cachefiles
ceph ceph: add more debug info when decoding mdsmap 2019-12-09 20:55:10 +01:00
cifs cifs: Optimize readdir on reparse points 2019-12-23 09:04:44 -06:00
coda y2038: add inode timestamp clamping 2019-09-19 09:42:37 -07:00
configfs configfs: calculate the depth of parent item 2019-11-06 18:36:01 +01:00
cramfs cramfs: fix usage on non-MTD device 2019-11-23 21:44:49 -05:00
crypto fscrypt: improve format of no-key names 2020-01-22 14:50:03 -08:00
debugfs Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-12-06 09:06:58 -08:00
devpts devpts_pty_kill(): don't bother with d_delete() 2019-09-03 09:30:56 -04:00
dlm
ecryptfs compat_ioctl: remove most of fs/compat_ioctl.c 2019-12-01 13:46:15 -08:00
efivarfs
efs fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
erofs Changes since last update: 2019-12-11 12:25:32 -08:00
exportfs race in exportfs_decode_fh() 2019-11-11 09:21:59 -05:00
ext2 \n 2019-11-30 11:16:07 -08:00
ext4 fscrypt: Allow modular crypto algorithms 2019-12-31 10:33:51 -06:00
f2fs fscrypt: Allow modular crypto algorithms 2019-12-31 10:33:51 -06:00
fat compat_ioctl: move drivers to compat_ptr_ioctl 2019-10-23 17:23:43 +02:00
freevxfs fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
fscache
fuse pipe: Fix iteration end check in fuse_dev_splice_write() 2019-12-06 13:57:04 -08:00
gfs2 GFS2 changes for this merge window: 2019-12-05 13:20:11 -08:00
hfs
hfsplus
hostfs
hpfs fs: compat_ioctl: move FITRIM emulation into file systems 2019-10-23 17:23:46 +02:00
hugetlbfs hugetlb: remove unused hstate in hugetlb_fault_mutex_hash() 2019-12-01 12:59:08 -08:00
iomap iomap: stop using ioend after it's been freed in iomap_finish_ioend() 2019-12-05 07:41:16 -08:00
isofs y2038: add inode timestamp clamping 2019-09-19 09:42:37 -07:00
jbd2 This merge window saw the the following new featuers added to ext4: 2019-11-30 10:53:02 -08:00
jffs2 Revert "jffs2: Fix possible null-pointer dereferences in jffs2_add_frag_to_fragtree()" 2019-11-29 11:29:58 +01:00
jfs y2038: add inode timestamp clamping 2019-09-19 09:42:37 -07:00
kernfs Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-12-06 09:06:58 -08:00
lockd NFSv4.1: Don't rebind to the same source port when reconnecting to the server 2019-11-03 21:28:45 -05:00
minix fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
nfs NFS4: Trace lock reclaims 2019-11-18 11:04:32 +01:00
nfs_common
nfsd This is a relatively quiet cycle for nfsd, mainly various bugfixes. 2019-12-07 16:56:00 -08:00
nilfs2 fs: compat_ioctl: move FITRIM emulation into file systems 2019-10-23 17:23:46 +02:00
nls
notify fs: call fsnotify_sb_delete after evict_inodes 2019-12-18 00:03:01 -05:00
ntfs ntfs: remove (un)?likely() from IS_ERR() conditions 2019-09-26 10:10:44 -07:00
ocfs2 Merge branch 'akpm' (patches from Andrew) 2019-12-01 20:36:41 -08:00
omfs fs: omfs: Initialize filesystem timestamp ranges 2019-08-30 08:11:25 -07:00
openpromfs
orangefs orangefs: posix open permission checking... 2019-12-04 08:52:55 -05:00
overlayfs overlayfs fixes for 5.5-rc2 2019-12-14 11:13:54 -08:00
proc sched/cputime, proc/stat: Fix incorrect guest nice cpustat value 2019-12-11 07:09:58 +01:00
pstore pstore: Make pstore_choose_compression() static 2019-10-29 09:43:03 -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 fs: avoid softlockups in s_inodes iterators 2019-12-18 00:03:01 -05:00
ramfs vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API 2019-09-12 21:05:34 -04:00
reiserfs reiserfs: replace open-coded atomic_dec_and_mutex_lock() 2019-11-05 12:25:22 +01:00
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
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 ubifs: allow both hash and disk name to be provided in no-key names 2020-01-22 14:49:56 -08:00
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 treewide: Use sizeof_field() macro 2019-12-09 10:36:44 -08:00
xfs xfs: Make the symbol 'xfs_rtalloc_log_count' static 2019-12-20 08:07:31 -08:00
aio.c y2038: syscall implementation cleanups 2019-12-01 14:00:59 -08:00
anon_inodes.c
attr.c timestamp_truncate: Replace users of timespec64_trunc 2019-08-30 07:27:17 -07:00
bad_inode.c
binfmt_aout.c
binfmt_elf.c fs/binfmt_elf.c: extract elf_read() function 2019-12-04 19:44:13 -08:00
binfmt_elf_fdpic.c y2038: elfcore: Use __kernel_old_timeval for process times 2019-11-15 14:38:29 +01:00
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
block_dev.c block: don't send uevent for empty disk when not invalidating 2019-12-02 18:49:30 -07:00
buffer.c fs/buffer.c: include internal.h for missing declarations 2019-12-01 06:29:17 -08:00
char_dev.c
compat.c
compat_binfmt_elf.c y2038: elfcore: Use __kernel_old_timeval for process times 2019-11-15 14:38:29 +01:00
compat_ioctl.c New code for 5.5: 2019-12-02 14:46:22 -08:00
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 New code for 5.5: 2019-11-30 10:44:49 -08:00
dcache.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-12-08 11:08:28 -08:00
dcookies.c
direct-io.c fs/direct-io.c: keep dio_warn_stale_pagecache() when CONFIG_BLOCK=n 2019-12-01 06:29:18 -08:00
drop_caches.c fs: avoid softlockups in s_inodes iterators 2019-12-18 00:03:01 -05:00
eventfd.c
eventpoll.c fs/epoll: remove unnecessary wakeups of nested epoll 2019-12-04 19:44:13 -08:00
exec.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-12-03 12:20:25 -08:00
fcntl.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-12-08 11:08:28 -08:00
fhandle.c fs/handle.c - fix up kerneldoc 2019-08-07 21:51:47 -04:00
file.c fs: remove ksys_dup() 2019-12-12 19:00:36 +01:00
file_table.c vfs: Export flush_delayed_fput for use by knfsd. 2019-08-19 11:00:39 -04:00
filesystems.c
fs-writeback.c cgroup,writeback: don't switch wbs immediately on dead wbs if the memcg is dead 2019-11-08 13:37:24 -07:00
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
fs_struct.c
fs_types.c
fsopen.c
inode.c fscrypt: don't allow v1 policies with casefolding 2020-01-22 14:47:15 -08:00
internal.h make __d_alloc() static 2019-10-25 14:08:24 -04:00
io-wq.c io-wq: add cond_resched() to worker thread 2019-12-24 09:14:29 -07:00
io-wq.h io-wq: re-add io_wq_current_is_worker() 2019-12-17 19:57:20 -07:00
io_uring.c io_uring: pass in 'sqe' to the prep handlers 2019-12-20 10:04:50 -07:00
ioctl.c New code for 5.5: 2019-12-02 14:46:22 -08:00
Kconfig io-wq: small threadpool implementation for io_uring 2019-10-29 12:43:00 -06:00
Kconfig.binfmt
libfs.c fs/libfs.c: fix kernel-doc warning 2019-10-14 15:04:01 -07:00
locks.c locks: print unsigned ino in /proc/locks 2019-12-29 09:00:58 -05:00
Makefile io-wq: small threadpool implementation for io_uring 2019-10-29 12:43:00 -06:00
mbcache.c
mount.h
mpage.c
namei.c Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-12-06 09:06:58 -08:00
namespace.c init: use do_mount() instead of ksys_mount() 2019-12-12 14:50:05 +01:00
no-block.c
nsfs.c
open.c Revert "vfs: properly and reliably lock f_pos in fdget_pos()" 2019-11-26 11:34:06 -08:00
pipe.c pipe: fix empty pipe check in pipe_write() 2019-12-22 09:47:47 -08:00
pnode.c
pnode.h
posix_acl.c
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 filldir[64]: remove WARN_ON_ONCE() for bad directory entries 2019-10-18 18:41:16 -04:00
select.c y2038: syscalls: change remaining timeval to __kernel_old_timeval 2019-11-15 14:38:29 +01:00
seq_file.c seq_file: fix problem when seeking mid-record 2019-08-13 16:06:52 -07:00
signalfd.c
splice.c pipe: remove 'waiting_writers' merging logic 2019-12-07 13:21:01 -08:00
stack.c
stat.c
statfs.c vfs: Fix EOVERFLOW testing in put_compat_statfs64 2019-10-03 14:21:35 -07:00
super.c fs: call fsnotify_sb_delete after evict_inodes 2019-12-18 00:03:01 -05:00
sync.c
timerfd.c y2038: timerfd: Use timespec64 internally 2019-11-15 14:38:30 +01:00
userfaultfd.c Merge branch 'akpm' (patches from Andrew) 2019-12-01 20:36:41 -08:00
utimes.c y2038: syscalls: change remaining timeval to __kernel_old_timeval 2019-11-15 14:38:29 +01:00
xattr.c