vfs: Verify acls are valid within superblock's s_user_ns.
Update posix_acl_valid to verify that an acl is within a user namespace.
Update the callers of posix_acl_valid to pass in an appropriate
user namespace. For posix_acl_xattr_set and v9fs_xattr_set_acl pass in
inode->i_sb->s_user_ns to posix_acl_valid. For md_unpack_acl pass in
&init_user_ns as no inode or superblock is in sight.
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 8a4a266..647c281 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -205,7 +205,7 @@
* Check if an acl is valid. Returns 0 if it is, or -E... otherwise.
*/
int
-posix_acl_valid(const struct posix_acl *acl)
+posix_acl_valid(struct user_namespace *user_ns, const struct posix_acl *acl)
{
const struct posix_acl_entry *pa, *pe;
int state = ACL_USER_OBJ;
@@ -225,7 +225,7 @@
case ACL_USER:
if (state != ACL_USER)
return -EINVAL;
- if (!uid_valid(pa->e_uid))
+ if (!kuid_has_mapping(user_ns, pa->e_uid))
return -EINVAL;
needs_mask = 1;
break;
@@ -240,7 +240,7 @@
case ACL_GROUP:
if (state != ACL_GROUP)
return -EINVAL;
- if (!gid_valid(pa->e_gid))
+ if (!kgid_has_mapping(user_ns, pa->e_gid))
return -EINVAL;
needs_mask = 1;
break;
@@ -845,7 +845,7 @@
return PTR_ERR(acl);
if (acl) {
- ret = posix_acl_valid(acl);
+ ret = posix_acl_valid(inode->i_sb->s_user_ns, acl);
if (ret)
goto out;
}