This is a note to let you know that I've just added the patch titled
ubifs: do_rename: Fix wrong space budget when target inode's nlink > 1
to the 4.19-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:
ubifs-do_rename-fix-wrong-space-budget-when-target-i.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 8ab641cd8c736ae61963cf5db5da3f29fb9a26e0
Author: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
Date: Tue Oct 11 11:47:31 2022 +0800
ubifs: do_rename: Fix wrong space budget when target inode's nlink > 1
[ Upstream commit 25fce616a61fc2f1821e4a9ce212d0e064707093 ]
If target inode is a special file (eg. block/char device) with nlink
count greater than 1, the inode with ui->data will be re-written on
disk. However, UBIFS losts target inode's data_len while doing space
budget. Bad space budget may let make_reservation() return with -ENOSPC,
which could turn ubifs to read-only mode in do_writepage() process.
Fetch a reproducer in [Link].
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216494
Fixes: 1e51764a3c2ac0 ("UBIFS: add new flash file system")
Signed-off-by: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
Signed-off-by: Richard Weinberger <richard@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index 89c5c2abc0faf..3b93b14e00412 100644
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -1309,9 +1309,13 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry,
old_dentry, old_inode->i_ino, old_dir->i_ino,
new_dentry, new_dir->i_ino, flags);
- if (unlink)
+ if (unlink) {
ubifs_assert(c, inode_is_locked(new_inode));
+ /* Budget for old inode's data when its nlink > 1. */
+ req.dirtied_ino_d = ALIGN(ubifs_inode(new_inode)->data_len, 8);
+ }
+
if (unlink && is_dir) {
err = ubifs_check_dir_empty(new_inode);
if (err)
