Commit graph

23 commits

Author SHA1 Message Date
Namjae Jeon
4e6e00704f exfat: fix shift-out-of-bounds in exfat_fill_super()
commit 78c276f549 upstream.

syzbot reported a warning which could cause shift-out-of-bounds issue.

Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x183/0x22e lib/dump_stack.c:120
 ubsan_epilogue lib/ubsan.c:148 [inline]
 __ubsan_handle_shift_out_of_bounds+0x432/0x4d0 lib/ubsan.c:395
 exfat_read_boot_sector fs/exfat/super.c:471 [inline]
 __exfat_fill_super fs/exfat/super.c:556 [inline]
 exfat_fill_super+0x2acb/0x2d00 fs/exfat/super.c:624
 get_tree_bdev+0x406/0x630 fs/super.c:1291
 vfs_get_tree+0x86/0x270 fs/super.c:1496
 do_new_mount fs/namespace.c:2881 [inline]
 path_mount+0x1937/0x2c50 fs/namespace.c:3211
 do_mount fs/namespace.c:3224 [inline]
 __do_sys_mount fs/namespace.c:3432 [inline]
 __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3409
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

exfat specification describe sect_per_clus_bits field of boot sector
could be at most 25 - sect_size_bits and at least 0. And sect_size_bits
can also affect this calculation, It also needs validation.
This patch add validation for sect_per_clus_bits and sect_size_bits
field of boot sector.

Fixes: 719c1e1829 ("exfat: add super block operations")
Cc: stable@vger.kernel.org # v5.9+
Reported-by: syzbot+da4fe66aaadd3c2e2d1c@syzkaller.appspotmail.com
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 11:38:41 +01:00
Linus Torvalds
0eac1102e9 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "Assorted stuff all over the place (the largest group here is
  Christoph's stat cleanups)"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: remove KSTAT_QUERY_FLAGS
  fs: remove vfs_stat_set_lookup_flags
  fs: move vfs_fstatat out of line
  fs: implement vfs_stat and vfs_lstat in terms of vfs_fstatat
  fs: remove vfs_statx_fd
  fs: omfs: use kmemdup() rather than kmalloc+memcpy
  [PATCH] reduce boilerplate in fsid handling
  fs: Remove duplicated flag O_NDELAY occurring twice in VALID_OPEN_FLAGS
  selftests: mount: add nosymfollow tests
  Add a "nosymfollow" mount option.
2020-10-24 12:26:05 -07:00
Tetsuhiro Kohada
04cee52fb8 exfat: remove 'rwoffset' in exfat_inode_info
Remove 'rwoffset' in exfat_inode_info and replace it with the parameter of
exfat_readdir().
Since rwoffset is referenced only by exfat_readdir(), it is not necessary
a exfat_inode_info's member.
Also, change cpos to point to the next of entry-set, and return the index
of dir-entry via dir_entry->entry.

Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
Acked-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-10-22 08:29:11 +09:00
Namjae Jeon
8ff006e57a exfat: fix use of uninitialized spinlock on error path
syzbot reported warning message:

Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d6/0x29e lib/dump_stack.c:118
 register_lock_class+0xf06/0x1520 kernel/locking/lockdep.c:893
 __lock_acquire+0xfd/0x2ae0 kernel/locking/lockdep.c:4320
 lock_acquire+0x148/0x720 kernel/locking/lockdep.c:5029
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
 spin_lock include/linux/spinlock.h:354 [inline]
 exfat_cache_inval_inode+0x30/0x280 fs/exfat/cache.c:226
 exfat_evict_inode+0x124/0x270 fs/exfat/inode.c:660
 evict+0x2bb/0x6d0 fs/inode.c:576
 exfat_fill_super+0x1e07/0x27d0 fs/exfat/super.c:681
 get_tree_bdev+0x3e9/0x5f0 fs/super.c:1342
 vfs_get_tree+0x88/0x270 fs/super.c:1547
 do_new_mount fs/namespace.c:2875 [inline]
 path_mount+0x179d/0x29e0 fs/namespace.c:3192
 do_mount fs/namespace.c:3205 [inline]
 __do_sys_mount fs/namespace.c:3413 [inline]
 __se_sys_mount+0x126/0x180 fs/namespace.c:3390
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

If exfat_read_root() returns an error, spinlock is used in
exfat_evict_inode() without initialization. This patch combines
exfat_cache_init_inode() with exfat_inode_init_once() to initialize
spinlock by slab constructor.

Fixes: c35b6810c4 ("exfat: add exfat cache")
Cc: stable@vger.kernel.org # v5.7+
Reported-by: syzbot <syzbot+b91107320911a26c9a95@syzkaller.appspotmail.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-10-07 14:27:13 +09:00
Al Viro
6d1349c769 [PATCH] reduce boilerplate in fsid handling
Get rid of boilerplate in most of ->statfs()
instances...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-09-18 16:45:50 -04:00
Tetsuhiro Kohada
7018ec68f0 exfat: retain 'VolumeFlags' properly
MediaFailure and VolumeDirty should be retained if these are set before
mounting.

In '3.1.13.3 Media Failure Field' of exfat specification describe:

 If, upon mounting a volume, the value of this field is 1,
 implementations which scan the entire volume for media failures and
 record all failures as "bad" clusters in the FAT (or otherwise resolve
 media failures) may clear the value of  this field to 0.

Therefore, We should not clear MediaFailure without scanning volume.

In '8.1 Recommended Write Ordering' of exfat specification describe:

 Clear the value of the VolumeDirty field to 0, if its value prior to
 the first step was 0.

Therefore, We should not clear VolumeDirty after mounting.
Also rename ERR_MEDIUM to MEDIA_FAILURE.

Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-08-12 08:31:13 +09:00
Tetsuhiro Kohada
2c7f8937ef exfat: remove EXFAT_SB_DIRTY flag
This flag is set/reset in exfat_put_super()/exfat_sync_fs()
to avoid sync_blockdev().
- exfat_put_super():
Before calling this, the VFS has already called sync_filesystem(),
so sync is never performed here.
- exfat_sync_fs():
After calling this, the VFS calls sync_blockdev(), so, it is meaningless
to check EXFAT_SB_DIRTY or to bypass sync_blockdev() here.

Remove the EXFAT_SB_DIRTY check to ensure synchronization.
And remove the code related to the flag.

Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-08-12 08:31:10 +09:00
Hyunchul Lee
a0271a15cf exfat: call sync_filesystem for read-only remount
We need to commit dirty metadata and pages to disk
before remounting exfat as read-only.

This fixes a failure in xfstests generic/452

generic/452 does the following:
cp something <exfat>/
mount -o remount,ro <exfat>

the <exfat>/something is corrupted. because while
exfat is remounted as read-only, exfat doesn't
have a chance to commit metadata and
vfs invalidates page caches in a block device.

Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Acked-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-29 17:11:08 +09:00
Al Viro
f341a7d8dc exfat: fix memory leak in exfat_parse_param()
butt3rflyh4ck reported memory leak found by syzkaller.

A param->string held by exfat_mount_options.

BUG: memory leak

unreferenced object 0xffff88801972e090 (size 8):
  comm "syz-executor.2", pid 16298, jiffies 4295172466 (age 14.060s)
  hex dump (first 8 bytes):
    6b 6f 69 38 2d 75 00 00                          koi8-u..
  backtrace:
    [<000000005bfe35d6>] kstrdup+0x36/0x70 mm/util.c:60
    [<0000000018ed3277>] exfat_parse_param+0x160/0x5e0
fs/exfat/super.c:276
    [<000000007680462b>] vfs_parse_fs_param+0x2b4/0x610
fs/fs_context.c:147
    [<0000000097c027f2>] vfs_parse_fs_string+0xe6/0x150
fs/fs_context.c:191
    [<00000000371bf78f>] generic_parse_monolithic+0x16f/0x1f0
fs/fs_context.c:231
    [<000000005ce5eb1b>] do_new_mount fs/namespace.c:2812 [inline]
    [<000000005ce5eb1b>] do_mount+0x12bb/0x1b30 fs/namespace.c:3141
    [<00000000b642040c>] __do_sys_mount fs/namespace.c:3350 [inline]
    [<00000000b642040c>] __se_sys_mount fs/namespace.c:3327 [inline]
    [<00000000b642040c>] __x64_sys_mount+0x18f/0x230 fs/namespace.c:3327
    [<000000003b024e98>] do_syscall_64+0xf6/0x7d0
arch/x86/entry/common.c:295
    [<00000000ce2b698c>] entry_SYSCALL_64_after_hwframe+0x49/0xb3

exfat_free() should call exfat_free_iocharset(), to prevent a leak
in case we fail after parsing iocharset= but before calling
get_tree_bdev().

Additionally, there's no point copying param->string in
exfat_parse_param() - just steal it, leaving NULL in param->string.
That's independent from the leak or fix thereof - it's simply
avoiding an extra copy.

Fixes: 719c1e1829 ("exfat: add super block operations")
Cc: stable@vger.kernel.org # v5.7
Reported-by: butt3rflyh4ck <butterflyhuangxx@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09 16:50:02 +09:00
Tetsuhiro Kohada
476189c0ef exfat: add boot region verification
Add Boot-Regions verification specified in exFAT specification.
Note that the checksum type is strongly related to the raw structure,
so the'u32 'type is used to clarify the number of bits.

Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09 16:49:19 +09:00
Tetsuhiro Kohada
33404a1598 exfat: separate the boot sector analysis
Separate the boot sector analysis to read_boot_sector().
And add a check for the fs_name field.
Furthermore, add a strict consistency check, because overlapping areas
can cause serious corruption.

Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09 16:49:14 +09:00
Tetsuhiro Kohada
181a9e8009 exfat: redefine PBR as boot_sector
Aggregate PBR related definitions and redefine as "boot_sector" to comply
with the exFAT specification.
And, rename variable names including 'pbr'.

Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09 16:49:10 +09:00
Jason Yan
cdc06129a6 exfat: remove the assignment of 0 to bool variable
There is no need to init 'sync' in exfat_set_vol_flags().
This also fixes the following coccicheck warning:

fs/exfat/super.c:104:6-10: WARNING: Assignment of 0/1 to bool variable

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09 16:48:53 +09:00
Joe Perches
d1727d55c0 exfat: Use a more common logging style
Remove the direct use of KERN_<LEVEL> in functions by creating
separate exfat_<level> macros.

Miscellanea:

o Remove several unnecessary terminating newlines in formats
o Realign arguments and fit to 80 columns where appropriate

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09 16:48:34 +09:00
Namjae Jeon
907fa89325 exfat: add the dummy mount options to be backward compatible with staging/exfat
As Ubuntu and Fedora release new version used kernel version equal to or
higher than v5.4, They started to support kernel exfat filesystem.

Linus reported a mount error with new version of exfat on Fedora:

        exfat: Unknown parameter 'namecase'

This is because there is a difference in mount option between old
staging/exfat and new exfat.  And utf8, debug, and codepage options as
well as namecase have been removed from new exfat.

This patch add the dummy mount options as deprecated option to be
backward compatible with old one.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-05-21 16:40:11 -07:00
Eric Sandeen
81df1ad406 exfat: truncate atimes to 2s granularity
The timestamp for access_time has double seconds granularity(There is no
10msIncrement field for access_time unlike create/modify_time).
exfat's atimes are restricted to only 2s granularity so after
we set an atime, round it down to the nearest 2s and set the
sub-second component of the timestamp to 0.

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-04-22 20:14:06 +09:00
Eric Sandeen
674a9985b8 exfat: properly set s_time_gran
The s_time_gran superblock field indicates the on-disk nanosecond
granularity of timestamps, and for exfat that seems to be 10ms, so
set s_time_gran to 10000000ns. Without this, in-memory timestamps
change when they get re-read from disk.

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-04-22 20:14:06 +09:00
Tetsuhiro Kohada
cbd445d9a9 exfat: remove 'bps' mount-option
remount fails because exfat_show_options() returns unsupported
option 'bps'.
> # mount -o ro,remount
> exfat: Unknown parameter 'bps'

To fix the problem, just remove 'bps' option from exfat_show_options().

Signed-off-by: Tetsuhiro Kohada <Kohada.Tetsuhiro@dc.MitsubishiElectric.co.jp>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-04-22 20:14:05 +09:00
Tetsuhiro Kohada
b0516833d8 exfat: Unify access to the boot sector
Unify access to boot sector via 'sbi->pbr_bh'.
This fixes vol_flags inconsistency at read failed in fs_set_vol_flags(),
and buffer_head leak in __exfat_fill_super().

Signed-off-by: Tetsuhiro Kohada <Kohada.Tetsuhiro@dc.MitsubishiElectric.co.jp>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-04-22 20:14:05 +09:00
Thomas Backlund
cd76ac258c exfat: add missing MODULE_ALIAS_FS()
This adds the necessary MODULE_ALIAS_FS() to exfat so the module gets
automatically loaded when an exfat filesystem is mounted.

Signed-off-by: Thomas Backlund <tmb@mageia.org>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-04-22 20:14:05 +09:00
Pali Rohár
b7e038a924 exfat: Fix discard support
Discard support was always unconditionally disabled. Now it is disabled
only in the case when blk_queue_discard() returns false.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-04-22 20:14:05 +09:00
Valdis Kletnieks
9acd0d5380 exfat: update file system parameter handling
Al Viro recently reworked the way file system parameters are handled
Update super.c to work with it in linux-next 20200203.

Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-05 21:00:40 -05:00
Namjae Jeon
719c1e1829 exfat: add super block operations
This adds the implementation of superblock operations for exfat.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-05 21:00:39 -05:00