From 21cb47be6fb9ece7e6ee63f6780986faa384a77c Mon Sep 17 00:00:00 2001
From: Christian Brauner <christian.brauner@ubuntu.com>
Date: Thu, 21 Jan 2021 14:19:25 +0100
Subject: inode: make init and permission helpers idmapped mount aware
The inode_owner_or_capable() helper determines whether the caller is the
owner of the inode or is capable with respect to that inode. Allow it to
handle idmapped mounts. If the inode is accessed through an idmapped
mount it according to the mount's user namespace. Afterwards the checks
are identical to non-idmapped mounts. If the initial user namespace is
passed nothing changes so non-idmapped mounts will see identical
behavior as before.
Similarly, allow the inode_init_owner() helper to handle idmapped
mounts. It initializes a new inode on idmapped mounts by mapping the
fsuid and fsgid of the caller from the mount's user namespace. If the
initial user namespace is passed nothing changes so non-idmapped mounts
will see identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-7-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---
fs/9p/acl.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
(limited to 'fs/9p/acl.c')
diff --git a/fs/9p/acl.c b/fs/9p/acl.c
index 6261719f6f2a..d77b28e8d57a 100644
--- a/fs/9p/acl.c
+++ b/fs/9p/acl.c
@@ -258,7 +258,7 @@ static int v9fs_xattr_set_acl(const struct xattr_handler *handler,
if (S_ISLNK(inode->i_mode))
return -EOPNOTSUPP;
- if (!inode_owner_or_capable(inode))
+ if (!inode_owner_or_capable(&init_user_ns, inode))
return -EPERM;
if (value) {
/* update the cached acl value */
--
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