ubifs: Rectify space budget for ubifs_xrename()

[ Upstream commit 1b2ba09060e41adb356b9ae58ef94a7390928004 ]

There is no space budget for ubifs_xrename(). It may let
make_reservation() return with -ENOSPC, which could turn
ubifs to read-only mode in do_writepage() process.
Fix it by adding space budget for ubifs_xrename().

Fetch a reproducer in [Link].

Link: https://bugzilla.kernel.org/show_bug.cgi?id=216569
Fixes: 9ec64962afb170 ("ubifs: Implement RENAME_EXCHANGE")
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index aaff3f3..94634b8 100644 (file)
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -1576,6 +1576,10 @@ static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry,
                return err;
        }
 
+       err = ubifs_budget_space(c, &req);
+       if (err)
+               goto out;
+
        lock_4_inodes(old_dir, new_dir, NULL, NULL);
 
        time = current_time(old_dir);
@@ -1601,6 +1605,7 @@ static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry,
        unlock_4_inodes(old_dir, new_dir, NULL, NULL);
        ubifs_release_budget(c, &req);
 
+out:
        fscrypt_free_filename(&fst_nm);
        fscrypt_free_filename(&snd_nm);
        return err;