linux/fs
Ye Bin e3912775b4 ext4: fix use-after-free in ext4_search_dir
commit c186f0887f upstream.

We got issue as follows:
EXT4-fs (loop0): mounted filesystem without journal. Opts: ,errors=continue
==================================================================
BUG: KASAN: use-after-free in ext4_search_dir fs/ext4/namei.c:1394 [inline]
BUG: KASAN: use-after-free in search_dirblock fs/ext4/namei.c:1199 [inline]
BUG: KASAN: use-after-free in __ext4_find_entry+0xdca/0x1210 fs/ext4/namei.c:1553
Read of size 1 at addr ffff8881317c3005 by task syz-executor117/2331

CPU: 1 PID: 2331 Comm: syz-executor117 Not tainted 5.10.0+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:83 [inline]
 dump_stack+0x144/0x187 lib/dump_stack.c:124
 print_address_description+0x7d/0x630 mm/kasan/report.c:387
 __kasan_report+0x132/0x190 mm/kasan/report.c:547
 kasan_report+0x47/0x60 mm/kasan/report.c:564
 ext4_search_dir fs/ext4/namei.c:1394 [inline]
 search_dirblock fs/ext4/namei.c:1199 [inline]
 __ext4_find_entry+0xdca/0x1210 fs/ext4/namei.c:1553
 ext4_lookup_entry fs/ext4/namei.c:1622 [inline]
 ext4_lookup+0xb8/0x3a0 fs/ext4/namei.c:1690
 __lookup_hash+0xc5/0x190 fs/namei.c:1451
 do_rmdir+0x19e/0x310 fs/namei.c:3760
 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x445e59
Code: 4d c7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 1b c7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff2277fac8 EFLAGS: 00000246 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 0000000000400280 RCX: 0000000000445e59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200000c0
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000002
R10: 00007fff2277f990 R11: 0000000000000246 R12: 0000000000000000
R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000

The buggy address belongs to the page:
page:0000000048cd3304 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x1317c3
flags: 0x200000000000000()
raw: 0200000000000000 ffffea0004526588 ffffea0004528088 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881317c2f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881317c2f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8881317c3000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff8881317c3080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881317c3100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

ext4_search_dir:
  ...
  de = (struct ext4_dir_entry_2 *)search_buf;
  dlimit = search_buf + buf_size;
  while ((char *) de < dlimit) {
  ...
    if ((char *) de + de->name_len <= dlimit &&
	 ext4_match(dir, fname, de)) {
	    ...
    }
  ...
    de_len = ext4_rec_len_from_disk(de->rec_len, dir->i_sb->s_blocksize);
    if (de_len <= 0)
      return -1;
    offset += de_len;
    de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
  }

Assume:
de=0xffff8881317c2fff
dlimit=0x0xffff8881317c3000

If read 'de->name_len' which address is 0xffff8881317c3005, obviously is
out of range, then will trigger use-after-free.
To solve this issue, 'dlimit' must reserve 8 bytes, as we will read
'de->name_len' to judge if '(char *) de + de->name_len' out of range.

Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220324064816.1209985-1-yebin10@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-27 14:39:01 +02:00
..
9p Revert "fs/9p: search open fids first" 2022-02-08 18:34:04 +01:00
adfs
affs
afs afs: Fix mmap 2021-12-22 09:32:45 +01:00
autofs autofs: fix wait name hash calculation in autofs_wait() 2021-10-20 21:09:02 -04:00
befs isystem: ship and use stdarg.h 2021-08-19 09:02:55 +09:00
bfs
btrfs btrfs: mark resumed async balance as writing 2022-04-20 09:34:19 +02:00
cachefiles cachefiles: Change %p in format strings to something else 2021-08-27 13:34:02 +01:00
ceph ceph: fix memory leak in ceph_readdir when note_last_dentry returns error 2022-04-13 20:59:10 +02:00
cifs cifs: Check the IOCB_DIRECT flag, not O_DIRECT 2022-04-27 14:38:56 +02:00
coda
configfs configfs: fix a race in configfs_{,un}register_subsystem() 2022-03-02 11:48:02 +01:00
cramfs
crypto fscrypt: allow 256-bit master keys with AES-256-XTS 2021-11-18 19:16:11 +01:00
debugfs debugfs: lockdown: Allow reading debugfs files that are not world readable 2022-01-27 11:03:55 +01:00
devpts fsnotify: fix fsnotify hooks in pseudo filesystems 2022-02-01 17:27:01 +01:00
dlm fs: dlm: filter user dlm messages for kernel locks 2022-01-27 11:04:23 +01:00
ecryptfs
efivarfs
efs
erofs erofs: fix deadlock when shrink erofs slab 2021-12-01 09:04:50 +01:00
exfat exfat: fix i_blocks for files truncated over 4 GiB 2022-03-08 19:12:32 +01:00
exportfs
ext2 ext2: correct max file size computing 2022-04-08 14:23:35 +02:00
ext4 ext4: fix use-after-free in ext4_search_dir 2022-04-27 14:39:01 +02:00
f2fs f2fs: compress: fix to print raw data size in error path of lz4 decompression 2022-04-08 14:23:58 +02:00
fat linux-kselftest-kunit-5.15-rc1 2021-09-02 12:32:12 -07:00
freevxfs
fscache fscache: Remove an unused static variable 2021-10-04 22:13:12 +01:00
fuse fuse: fix pipe buffer lifetime for direct_io 2022-03-16 14:23:42 +01:00
gfs2 gfs2: assign rgrp glock before compute_bitstructs 2022-04-27 14:38:51 +02:00
hfs hfs: add lock nesting notation to hfs_find_init 2021-07-15 10:13:49 -07:00
hfsplus hfsplus: report create_date to kstat.btime 2021-07-01 11:06:06 -07:00
hostfs hostfs: support splice_write 2021-08-26 22:28:02 +02:00
hpfs hpfs: use iomap_fiemap to implement ->fiemap 2021-07-27 11:00:36 +02:00
hugetlbfs mm, hugetlb: allow for "high" userspace addresses 2022-04-27 14:38:57 +02:00
iomap iomap: Fix inline extent handling in iomap_readpage 2021-12-01 09:04:44 +01:00
isofs isofs: Fix out of bound access for corrupted isofs image 2021-11-12 15:05:50 +01:00
jbd2 ext4: fast commit may not fallback for ineligible commit 2022-03-08 19:12:32 +01:00
jffs2 jffs2: fix memory leak in jffs2_scan_medium 2022-04-08 14:22:53 +02:00
jfs jfs: prevent NULL deref in diFree 2022-04-13 20:59:13 +02:00
kernfs kernfs: don't create a negative dentry if inactive node exists 2021-10-04 10:27:18 +02:00
ksmbd ksmbd: don't align last entry offset in smb2 query directory 2022-02-23 12:03:18 +01:00
lockd lockd: fix failure to cleanup client locks 2022-02-05 12:38:57 +01:00
minix minix: fix bug when opening a file with O_DIRECT 2022-04-13 20:59:10 +02:00
netfs netfs: fix parameter of cleanup() 2021-12-29 12:28:59 +01:00
nfs NFSv4: fix open failure with O_ACCMODE flag 2022-04-13 20:59:15 +02:00
nfs_common nfs: Fix kerneldoc warning shown up by W=1 2021-10-04 22:02:17 +01:00
nfsd NFSD: Fix nfsd_breaker_owns_lease() return values 2022-04-08 14:23:57 +02:00
nilfs2 Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
nls
notify fanotify: Fix stale file descriptor in copy_event_to_user() 2022-02-05 12:38:59 +01:00
ntfs ntfs: add sanity check on allocation size 2022-04-08 14:23:58 +02:00
ntfs3 Fixed xfstests generic/016 generic/021 generic/022 generic/041 generic/274 generic/423, 2021-10-15 09:58:11 -04:00
ocfs2 ocfs2: fix crash when mount with quota enabled 2022-04-08 14:22:56 +02:00
omfs
openpromfs
orangefs orangefs: Fix the size of a memory allocation in orangefs_bufmap_alloc() 2022-01-20 09:13:13 +01:00
overlayfs ovl: fix NULL pointer dereference in copy up warning 2022-02-05 12:38:59 +01:00
proc proc: bootconfig: Add null pointer check 2022-04-08 14:24:12 +02:00
pstore pstore: Don't use semaphores in always-atomic-context code 2022-04-08 14:23:01 +02:00
qnx4 qnx4: work around gcc false positive warning bug 2021-09-21 08:36:48 -07:00
qnx6
quota quota: make dquot_quota_sync return errors from ->sync_fs 2022-02-23 12:03:06 +01:00
ramfs
reiserfs Kbuild updates for v5.15 2021-09-03 15:33:47 -07:00
romfs
smbfs_common cifs: Fix crash on unload of cifs_arc4.ko 2021-12-14 10:57:12 +01:00
squashfs squashfs: use bvec_virt 2021-08-16 10:50:32 -06:00
sysfs sysfs: Allow deferred execution of iomem_get_mapping() 2021-08-06 13:05:28 +02:00
sysv
tracefs tracefs: Set the group ownership in apply_options() not parse_options() 2022-03-02 11:48:05 +01:00
ubifs ubifs: rename_whiteout: correct old_dir size computing 2022-04-08 14:24:08 +02:00
udf udf: Fix NULL ptr deref when converting from inline format 2022-02-01 17:27:00 +01:00
ufs isystem: ship and use stdarg.h 2021-08-19 09:02:55 +09:00
unicode
vboxsf vboxfs: fix broken legacy mount signature checking 2021-09-27 11:26:21 -07:00
verity fs-verity: fix signed integer overflow with i_size near S64_MAX 2021-09-22 10:56:34 -07:00
xfs xfs: return errors in xfs_fs_sync_fs 2022-04-27 14:38:50 +02:00
zonefs zonefs: add MODULE_ALIAS_FS 2021-12-22 09:32:48 +01:00
aio.c aio: Fix incorrect usage of eventfd_signal_allowed() 2021-12-14 10:57:22 +01:00
anon_inodes.c
attr.c fs: handle circular mappings correctly 2021-11-25 09:48:46 +01:00
bad_inode.c vfs: add rcu argument to ->get_acl() callback 2021-08-18 22:08:24 +02:00
binfmt_aout.c binfmt: a.out: Fix bogus semicolon 2021-09-05 10:15:05 -07:00
binfmt_elf_fdpic.c coredump: Snapshot the vmas in do_coredump 2022-04-08 14:24:17 +02:00
binfmt_elf.c coredump: Use the vma snapshot in fill_files_note 2022-04-08 14:24:18 +02:00
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
buffer.c mm: fs: fix lru_cache_disabled race in bh_lru 2022-04-08 14:22:54 +02:00
char_dev.c
compat_binfmt_elf.c
coredump.c coredump: Use the vma snapshot in fill_files_note 2022-04-08 14:24:18 +02:00
d_path.c d_path: make 'prepend()' fill up the buffer exactly on overflow 2021-09-02 10:07:29 -07:00
dax.c New code for 5.15: 2021-08-31 11:13:35 -07:00
dcache.c
direct-io.c
drop_caches.c fs: drop_caches: fix skipping over shadow cache inodes 2021-09-03 09:58:10 -07:00
eventfd.c eventfd: Export eventfd_wake_count to modules 2021-09-06 07:20:56 -04:00
eventpoll.c ARM development updates for 5.15: 2021-09-09 13:25:49 -07:00
exec.c exec: Force single empty string when argv is empty 2022-04-08 14:23:01 +02:00
fcntl.c Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
fhandle.c
file_table.c
file.c fs: fix fd table size alignment properly 2022-04-08 14:23:54 +02:00
filesystems.c fs: simplify get_filesystem_list / get_all_fs_names 2021-08-23 01:25:40 -04:00
fs_context.c vfs: fs_context: fix up param length parsing in legacy_parse_param 2022-01-20 09:13:14 +01:00
fs_parser.c namei: Standardize callers of filename_lookup() 2021-09-07 16:07:47 -04:00
fs_pin.c
fs_struct.c
fs_types.c
fs-writeback.c Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
fsopen.c
init.c
inode.c fs: export an inode_update_time helper 2021-11-25 09:49:08 +01:00
internal.h block: simplify the block device syncing code 2022-04-27 14:38:50 +02:00
io_uring.c io_uring: use nospec annotation for more indexes 2022-04-20 09:34:17 +02:00
io-wq.c io-wq: drop wqe lock before creating new worker 2021-12-22 09:32:51 +01:00
io-wq.h io-wq: provide a way to limit max number of workers 2021-08-29 07:55:55 -06:00
ioctl.c New code for 5.15: 2021-08-31 11:06:32 -07:00
Kconfig 4 cifs/smb3 fixes, one for DFS reconnect, and one to begin creating common headers for server and client and the other two to rename the cifs_common directory to smbfs_common to be more consistent ie change use of the name cifs to smb which is more accurate 2021-09-12 10:10:21 -07:00
Kconfig.binfmt binfmt: remove support for em86 (alpha only) 2021-07-25 22:33:03 -07:00
kernel_read_file.c vfs: check fd has read access in kernel_read_file_from_fd() 2021-10-18 20:22:03 -10:00
libfs.c
locks.c Revert "memcg: enable accounting for file lock caches" 2021-09-07 11:21:48 -07:00
Makefile 4 cifs/smb3 fixes, one for DFS reconnect, and one to begin creating common headers for server and client and the other two to rename the cifs_common directory to smbfs_common to be more consistent ie change use of the name cifs to smb which is more accurate 2021-09-12 10:10:21 -07:00
mbcache.c
mount.h
mpage.c
namei.c VFS: filename_create(): fix incorrect intent. 2022-04-27 14:38:57 +02:00
namespace.c fs/mount_setattr: always cleanup mount_kattr 2022-01-05 12:42:39 +01:00
no-block.c
nsfs.c
open.c mm, thp: fix incorrect unmap behavior for private pages 2021-11-18 19:17:17 +01:00
pipe.c watch_queue: Fix lack of barrier/sync/lock between post and read 2022-03-16 14:23:44 +01:00
pnode.c
pnode.h
posix_acl.c ovl: enable RCU'd ->get_acl() 2021-08-18 22:08:24 +02:00
proc_namespace.c
read_write.c fs: clean up after mandatory file locking support removal 2021-08-24 07:52:45 -04:00
readdir.c
remap_range.c fs: remove mandatory file locking support 2021-08-23 06:15:36 -04:00
select.c select: Fix indefinitely sleeping task in poll_schedule_timeout() 2022-01-29 10:58:25 +01:00
seq_file.c seq_file: disallow extremely large seq buffer allocations 2021-07-19 17:18:48 -07:00
signalfd.c signalfd: use wake_up_pollfree() 2021-12-14 10:57:15 +01:00
splice.c
stack.c
stat.c stat: fix inconsistency between struct stat and struct compat_stat 2022-04-27 14:38:57 +02:00
statfs.c
super.c vfs: make freeze_super abort when sync_filesystem returns error 2022-02-23 12:03:05 +01:00
sync.c vfs: make sync_filesystem return errors from ->sync_fs 2022-04-27 14:38:50 +02:00
timerfd.c timerfd: Provide timerfd_resume() 2021-08-10 17:57:22 +02:00
userfaultfd.c userfaultfd: fix a race between writeprotect and exit_mmap() 2021-10-18 20:22:02 -10:00
utimes.c
xattr.c