Commit Graph

8 Commits

Author SHA1 Message Date
Namjae Jeon
950e271397 exfat: use fat ioctls definitions from include/uapi/linux/msdos_fs.h
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2023-10-30 21:08:39 +09:00
Namjae Jeon
47fb2035ce exfat: handle unreconized benign secondary entries
Sony PXW-Z280 camera add vendor allocation entries to directory of
pictures. Currently, linux exfat does not support it and the file is
not visible. This patch handle vendor extension and allocation entries
as unreconized benign secondary entries. As described in the specification,
it is recognized but ignored, and when deleting directory entry set,
the associated clusters allocation are removed as well as benign secondary
directory entries.

Reported-by: Barócsi Dénes <admin@tveger.hu>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2023-01-13 22:53:51 +09:00
Namjae Jeon
5d39deced1 exfat: fix shift-out-of-bounds in exfat_fill_super()
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: 719c1e182916 ("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>
2021-02-01 10:35:05 +09:00
Tetsuhiro Kohada
bfea1fb6bb 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>
2020-09-10 09:02:45 +09:00
Tetsuhiro Kohada
c099996e89 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>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-04 15:42:41 +09:00
Tetsuhiro Kohada
461d45b45c 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>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-04 15:42:38 +09:00
Tetsuhiro Kohada
9772742131 exfat: replace 'time_ms' with 'time_cs'
Replace time_ms  with time_cs in the file directory entry structure
and related functions.

The unit of create_time_ms/modify_time_ms in File Directory Entry are not
'milli-second', but 'centi-second'.
The exfat specification uses the term '10ms', but instead use 'cs' as in
msdos_fs.h.

Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2020-05-03 23:11:32 +09:00
Namjae Jeon
9273f3d387 exfat: initial commit
Signed-off-by: Namjae Jeon <linkinjeon@gmail.com>
2020-02-03 21:47:19 +09:00