This is a note to let you know that I've just added the patch titled
exportfs: support idmapped mounts
to the 5.15-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:
exportfs-support-idmapped-mounts.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3a761d72fa62eec8913e45d29375344f61706541 Mon Sep 17 00:00:00 2001
From: Christian Brauner <brauner@xxxxxxxxxx>
Date: Mon, 4 Apr 2022 12:51:41 +0200
Subject: exportfs: support idmapped mounts
From: Christian Brauner <brauner@xxxxxxxxxx>
commit 3a761d72fa62eec8913e45d29375344f61706541 upstream.
Make the two locations where exportfs helpers check permission to lookup
a given inode idmapped mount aware by switching it to the lookup_one()
helper. This is a bugfix for the open_by_handle_at() system call which
doesn't take idmapped mounts into account currently. It's not tied to a
specific commit so we'll just Cc stable.
In addition this is required to support idmapped base layers in overlay.
The overlay filesystem uses exportfs to encode and decode file handles
for its index=on mount option and when nfs_export=on.
Cc: <stable@xxxxxxxxxxxxxxx>
Cc: <linux-fsdevel@xxxxxxxxxxxxxxx>
Tested-by: Giuseppe Scrivano <gscrivan@xxxxxxxxxx>
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Christian Brauner (Microsoft) <brauner@xxxxxxxxxx>
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/exportfs/expfs.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -145,7 +145,7 @@ static struct dentry *reconnect_one(stru
if (err)
goto out_err;
dprintk("%s: found name: %s\n", __func__, nbuf);
- tmp = lookup_one_len_unlocked(nbuf, parent, strlen(nbuf));
+ tmp = lookup_one_unlocked(mnt_user_ns(mnt), nbuf, parent, strlen(nbuf));
if (IS_ERR(tmp)) {
dprintk("%s: lookup failed: %d\n", __func__, PTR_ERR(tmp));
err = PTR_ERR(tmp);
@@ -525,7 +525,8 @@ exportfs_decode_fh_raw(struct vfsmount *
}
inode_lock(target_dir->d_inode);
- nresult = lookup_one_len(nbuf, target_dir, strlen(nbuf));
+ nresult = lookup_one(mnt_user_ns(mnt), nbuf,
+ target_dir, strlen(nbuf));
if (!IS_ERR(nresult)) {
if (unlikely(nresult->d_inode != result->d_inode)) {
dput(nresult);
Patches currently in stable-queue which might be from brauner@xxxxxxxxxx are
queue-5.15/fs-add-two-trivial-lookup-helpers.patch
queue-5.15/exportfs-support-idmapped-mounts.patch
