From: Zhihao Cheng chengzhihao1@huawei.com
hulk inclusion category: bugfix bugzilla: 187685, https://gitee.com/openeuler/kernel/issues/I5VVZX CVE: NA
--------------------------------
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@huawei.com Reviewed-by: Zhang Yi yi.zhang@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- fs/ubifs/dir.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index 1f13fd515ce7..1686e7aea823 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -1318,6 +1318,8 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, 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); err = ubifs_purge_xattrs(new_inode); if (err) return err;