22 Commits

Author SHA1 Message Date
Namjae Jeon
6b64974e02 exfat: check if filename entries exceeds max filename length
commit d42334578eba1390859012ebb91e1e556d51db49 upstream.

exfat_extract_uni_name copies characters from a given file name entry into
the 'uniname' variable. This variable is actually defined on the stack of
the exfat_readdir() function. According to the definition of
the 'exfat_uni_name' type, the file name should be limited 255 characters
(+ null teminator space), but the exfat_get_uniname_from_ext_entry()
function can write more characters because there is no check if filename
entries exceeds max filename length. This patch add the check not to copy
filename characters when exceeding max filename length.

Cc: stable@vger.kernel.org
Cc: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reported-by: Maxim Suhanov <dfirblog@gmail.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[Harshit: backport to 5.15.y]
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-26 14:23:37 +02:00
Sungjong Seo
1c33ca1e19 exfat: release s_lock before calling dir_emit()
commit ff84772fd45d486e4fc78c82e2f70ce5333543e6 upstream.

There is a potential deadlock reported by syzbot as below:

======================================================
WARNING: possible circular locking dependency detected
6.4.0-next-20230707-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor330/5073 is trying to acquire lock:
ffff8880218527a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock_killable include/linux/mmap_lock.h:151 [inline]
ffff8880218527a0 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5293 [inline]
ffff8880218527a0 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x369/0x510 mm/memory.c:5344
but task is already holding lock:
ffff888019f760e0 (&sbi->s_lock){+.+.}-{3:3}, at: exfat_iterate+0x117/0xb50 fs/exfat/dir.c:232

which lock already depends on the new lock.

Chain exists of:
  &mm->mmap_lock --> mapping.invalidate_lock#3 --> &sbi->s_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sbi->s_lock);
                               lock(mapping.invalidate_lock#3);
                               lock(&sbi->s_lock);
  rlock(&mm->mmap_lock);

Let's try to avoid above potential deadlock condition by moving dir_emit*()
out of sbi->s_lock coverage.

Fixes: ca06197382bd ("exfat: add directory operations")
Cc: stable@vger.kernel.org #v5.7+
Reported-by: syzbot+1741a5d9b79989c10bdc@syzkaller.appspotmail.com
Link: https://lore.kernel.org/lkml/00000000000078ee7e060066270b@google.com/T/#u
Tested-by: syzbot+1741a5d9b79989c10bdc@syzkaller.appspotmail.com
Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-11 15:13:56 +02:00
Yuezhang Mo
c2c3d86bd4 exfat: fix unexpected EOF while reading dir
commit 6cb5d1a16a51d080fbc1649a5144cbc5ca7d6f88 upstream.

If the position is not aligned with the dentry size, the return
value of readdir() will be NULL and errno is 0, which means the
end of the directory stream is reached.

If the position is aligned with dentry size, but there is no file
or directory at the position, exfat_readdir() will continue to
get dentry from the next dentry. So the dentry gotten by readdir()
may not be at the position.

After this commit, if the position is not aligned with the dentry
size, round the position up to the dentry size and continue to get
the dentry.

Fixes: ca06197382bd ("exfat: add directory operations")
Cc: stable@vger.kernel.org # v5.7+
Reported-by: Wang Yugui <wangyugui@e16-tech.com>
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:39:58 +01:00
Yuezhang Mo
0d3902cbcf exfat: fix reporting fs error when reading dir beyond EOF
commit 706fdcac002316893434d753be8cfb549fe1d40d upstream.

Since seekdir() does not check whether the position is valid, the
position may exceed the size of the directory. We found that for
a directory with discontinuous clusters, if the position exceeds
the size of the directory and the excess size is greater than or
equal to the cluster size, exfat_readdir() will return -EIO,
causing a file system error and making the file system unavailable.

Reproduce this bug by:

seekdir(dir, dir_size + cluster_size);
dirent = readdir(dir);

The following log will be printed if mount with 'errors=remount-ro'.

[11166.712896] exFAT-fs (sdb1): error, invalid access to FAT (entry 0xffffffff)
[11166.712905] exFAT-fs (sdb1): Filesystem has been set read-only

Fixes: 1e5654de0f51 ("exfat: handle wrong stream entry size in exfat_readdir()")
Cc: stable@vger.kernel.org # v5.7+
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:39:57 +01:00
Namjae Jeon
1e5654de0f exfat: handle wrong stream entry size in exfat_readdir()
The compatibility issue between linux exfat and exfat of some camera
company was reported from Florian. In their exfat, if the number of files
exceeds any limit, the DataLength in stream entry of the directory is
no longer updated. So some files created from camera does not show in
linux exfat. because linux exfat doesn't allow that cpos becomes larger
than DataLength of stream entry. This patch check DataLength in stream
entry only if the type is ALLOC_NO_FAT_CHAIN and add the check ensure
that dentry offset does not exceed max dentries size(256 MB) to avoid
the circular FAT chain issue.

Fixes: ca06197382bd ("exfat: add directory operations")
Cc: stable@vger.kernel.org # v5.9
Reported-by: Florian Cramer <flrncrmr@gmail.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Tested-by: Chris Down <chris@chrisdown.name>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2021-07-04 09:33:00 +09:00
Hyeongseok Kim
c6e2f52e30 exfat: speed up iterate/lookup by fixing start point of traversing cluster chain
When directory iterate and lookup is called, there's a buggy rewinding
of start point for traversing cluster chain to the parent directory
entry's first cluster. This caused repeated cluster chain traversing
from the first entry of the parent directory that would show worse
performance if huge amounts of files exist under the parent directory.
Fix not to rewind, make continue from currently referenced cluster and
dir entry.

Tested with 50,000 files under single directory / 256GB sdcard,
with command "time ls -l > /dev/null",
Before :     0m08.69s real     0m00.27s user     0m05.91s system
After  :     0m07.01s real     0m00.25s user     0m04.34s system

Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2021-04-27 20:45:07 +09:00
Hyeongseok Kim
23befe490b exfat: improve write performance when dirsync enabled
Degradation of write speed caused by frequent disk access for cluster
bitmap update on every cluster allocation could be improved by
selective syncing bitmap buffer. Change to flush bitmap buffer only
for the directory related operations.

Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com>
Acked-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2021-04-27 20:45:06 +09:00
Hyeongseok Kim
654762df2e exfat: add support ioctl and FITRIM function
Add FITRIM ioctl to enable discarding unused blocks while mounted.
As current exFAT doesn't have generic ioctl handler, add empty ioctl
function first, and add FITRIM handler.

Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2021-04-27 20:45:06 +09:00
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
Tetsuhiro Kohada
a7a241686c exfat: replace memcpy with structure assignment
Use structure assignment instead of memcpy.

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
Tetsuhiro Kohada
188df41f21 exfat: eliminate dead code in exfat_find()
The exfat_find_dir_entry() called by exfat_find() doesn't return -EEXIST.
Therefore, the root-dir information setting is never executed.

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
Tetsuhiro Kohada
8b0c471773 exfat: add error check when updating dir-entries
Add error check when synchronously updating dir-entries.

Suggested-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-08-12 08:31:12 +09:00
Tetsuhiro Kohada
3db3c3fb84 exfat: write multiple sectors at once
Write multiple sectors at once when updating dir-entries.
Add exfat_update_bhs() for that. It wait for write completion once
instead of sector by sector.
It's only effective if sync enabled.

Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-08-12 08:31:11 +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
Namjae Jeon
d2fa0c337d exfat: fix wrong hint_stat initialization in exfat_find_dir_entry()
We found the wrong hint_stat initialization in exfat_find_dir_entry().
It should be initialized when cluster is EXFAT_EOF_CLUSTER.

Fixes: ca06197382bd ("exfat: add directory operations")
Cc: stable@vger.kernel.org # v5.7
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-07-21 10:44:10 +09:00
Sungjong Seo
5267456e95 exfat: flush dirty metadata in fsync
generic_file_fsync() exfat used could not guarantee the consistency of
a file because it has flushed not dirty metadata but only dirty data pages
for a file.

Instead of that, use exfat_file_fsync() for files and directories so that
it guarantees to commit both the metadata and data pages for a file.

Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-29 17:11:18 +09:00
Hyeongseok.Kim
4ba6ccd695 exfat: Set the unused characters of FileName field to the value 0000h
Some fsck tool complain that padding part of the FileName field
is not set to the value 0000h. So let's maintain filesystem cleaner,
as exfat's spec. recommendation.

Signed-off-by: Hyeongseok.Kim <Hyeongseok@gmail.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-29 17:11:00 +09:00
Tetsuhiro Kohada
5875bf287d exfat: standardize checksum calculation
To clarify that it is a 16-bit checksum, the parts related to the 16-bit
checksum are renamed and change type to u16.
Furthermore, replace checksum calculation in exfat_load_upcase_table()
with exfat_calc_checksum32().

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 16:49:25 +09:00
Tetsuhiro Kohada
943af1fdac exfat: optimize dir-cache
Optimize directory access based on exfat_entry_set_cache.
 - Hold bh instead of copied d-entry.
 - Modify bh->data directly instead of the copied d-entry.
 - Write back the retained bh instead of rescanning the d-entry-set.
And
 - Remove unused cache related definitions.

Signed-off-by: Tetsuhiro Kohada <kohada.tetsuhiro@dc.mitsubishielectric.co.jp>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09 16:49:05 +09:00
Tetsuhiro Kohada
ed0f84d30b 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 <namjae.jeon@samsung.com>
2020-06-09 16:49:00 +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
ca06197382 exfat: add directory operations
This adds the implementation of directory 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>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-05 21:00:40 -05:00