linux-kernel - [PATCH 5.15 663/667] exportfs: support idmapped mounts

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue,  7 Jun 2022 19:05:28 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        Giuseppe Scrivano <gscrivan@...hat.com>,
        Amir Goldstein <amir73il@...il.com>,
        Christoph Hellwig <hch@....de>,
        "Christian Brauner (Microsoft)" <brauner@...nel.org>,
        Miklos Szeredi <mszeredi@...hat.com>
Subject: [PATCH 5.15 663/667] exportfs: support idmapped mounts

From: Christian Brauner <brauner@...nel.org>

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@...r.kernel.org>
Cc: <linux-fsdevel@...r.kernel.org>
Tested-by: Giuseppe Scrivano <gscrivan@...hat.com>
Reviewed-by: Amir Goldstein <amir73il@...il.com>
Reviewed-by: Christoph Hellwig <hch@....de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@...nel.org>
Signed-off-by: Miklos Szeredi <mszeredi@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 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);