Re: [PATCH v1] exfat: fix reporting fs error when reading dir beyond EOF

[Namjae Jeon]

2022-12-26 16:23 GMT+09:00, Yuezhang.Mo@xxxxxxxx <Yuezhang.Mo@xxxxxxxx>:
> 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()")
>
> Signed-off-by: Yuezhang Mo <Yuezhang.Mo@xxxxxxxx>
> Reviewed-by: Andy Wu <Andy.Wu@xxxxxxxx>
> Reviewed-by: Aoyama Wataru <wataru.aoyama@xxxxxxxx>
Applied, Thanks for your patch!