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| author | Christian Brauner <christian.brauner@ubuntu.com> | 2021-01-21 14:19:31 +0100 |
|---|---|---|
| committer | Christian Brauner <christian.brauner@ubuntu.com> | 2021-01-24 14:27:17 +0100 |
| commit | ba73d98745be1c10dc3cce68e8d7b95012d07d05 (patch) | |
| tree | 6b88b691fba3c40f8d1ad0c4bda7c98a376bd529 /fs/xattr.c | |
| parent | 0d56a4518d5eaf595a24ab2202e171330bb2ed72 (diff) | |
| download | lwn-ba73d98745be1c10dc3cce68e8d7b95012d07d05.tar.gz lwn-ba73d98745be1c10dc3cce68e8d7b95012d07d05.zip | |
namei: handle idmapped mounts in may_*() helpers
The may_follow_link(), may_linkat(), may_lookup(), may_open(),
may_o_create(), may_create_in_sticky(), may_delete(), and may_create()
helpers determine whether the caller is privileged enough to perform the
associated operations. Let them handle idmapped mounts by mapping the
inode or fsids according to the mount's user namespace. Afterwards the
checks are identical to non-idmapped inodes. The patch takes care to
retrieve the mount's user namespace right before performing permission
checks and passing it down into the fileystem so the user namespace
can't change in between by someone idmapping a mount that is currently
not idmapped. 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/20210121131959.646623-13-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>
Diffstat (limited to 'fs/xattr.c')
| -rw-r--r-- | fs/xattr.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/xattr.c b/fs/xattr.c index 79c439d31eaa..b3444e06cded 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -98,7 +98,7 @@ xattr_permission(struct user_namespace *mnt_userns, struct inode *inode, * to be writen back improperly if their true value is * unknown to the vfs. */ - if (HAS_UNMAPPED_ID(inode)) + if (HAS_UNMAPPED_ID(mnt_userns, inode)) return -EPERM; } |