linux/fs/exfat
Yuezhang Mo 706fdcac00 exfat: fix reporting fs error when reading dir beyond EOF
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: 1e5654de0f ("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>
2023-02-27 21:14:45 +09:00
..
balloc.c exfat: check if cluster num is valid 2022-05-23 11:17:30 +09:00
cache.c exfat: fix use of uninitialized spinlock on error path 2020-10-07 14:27:13 +09:00
dir.c exfat: fix reporting fs error when reading dir beyond EOF 2023-02-27 21:14:45 +09:00
exfat_fs.h exfat: fix overflow in sector and cluster conversion 2022-12-13 20:17:11 +09:00
exfat_raw.h exfat: fix shift-out-of-bounds in exfat_fill_super() 2021-02-22 09:55:13 +09:00
fatent.c exfat: fix overflow for large capacity partition 2022-09-04 09:38:40 +09:00
file.c exfat: remove i_size_write() from __exfat_truncate() 2022-12-12 11:02:51 +09:00
inode.c Description for this pull request: 2022-12-15 18:14:21 -08:00
Kconfig exfat: Improve wording of EXFAT_DEFAULT_IOCHARSET config option 2020-06-09 16:48:39 +09:00
Makefile exfat: add Kconfig and Makefile 2020-03-05 21:00:40 -05:00
misc.c exfat: Expand exfat_err() and co directly to pr_*() macro 2022-08-01 10:14:07 +09:00
namei.c exfat: remove unnecessary arguments from exfat_find_dir_entry() 2022-12-12 11:02:50 +09:00
nls.c exfat: Drop superfluous new line for error messages 2022-08-01 10:14:07 +09:00
super.c exfat: Drop superfluous new line for error messages 2022-08-01 10:14:07 +09:00