This is a note to let you know that I've just added the patch titled
exfat: fix reporting fs error when reading dir beyond EOF
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
exfat-fix-reporting-fs-error-when-reading-dir-beyond-eof.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 706fdcac002316893434d753be8cfb549fe1d40d Mon Sep 17 00:00:00 2001
From: Yuezhang Mo <Yuezhang.Mo@xxxxxxxx>
Date: Thu, 20 Oct 2022 14:27:37 +0800
Subject: exfat: fix reporting fs error when reading dir beyond EOF
From: Yuezhang Mo <Yuezhang.Mo@xxxxxxxx>
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@xxxxxxxxxxxxxxx # v5.7+
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@xxxxxxxx>
Reviewed-by: Andy Wu <Andy.Wu@xxxxxxxx>
Reviewed-by: Aoyama Wataru <wataru.aoyama@xxxxxxxx>
Reviewed-by: Sungjong Seo <sj1557.seo@xxxxxxxxxxx>
Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/exfat/dir.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/exfat/dir.c
+++ b/fs/exfat/dir.c
@@ -102,7 +102,7 @@ static int exfat_readdir(struct inode *i
clu.dir = ei->hint_bmap.clu;
}
- while (clu_offset > 0) {
+ while (clu_offset > 0 && clu.dir != EXFAT_EOF_CLUSTER) {
if (exfat_get_next_cluster(sb, &(clu.dir)))
return -EIO;
Patches currently in stable-queue which might be from Yuezhang.Mo@xxxxxxxx are
queue-5.10/exfat-fix-reporting-fs-error-when-reading-dir-beyond-eof.patch
queue-5.10/exfat-fix-inode-i_blocks-for-non-512-byte-sector-size-device.patch
queue-5.10/exfat-fix-unexpected-eof-while-reading-dir.patch
queue-5.10/exfat-redefine-dir_deleted-as-the-bad-cluster-number.patch
