Add checks to inode_change_ok to verify that uid and gid changes
will map into the superblock's user namespace. If they do not
fail with -EOVERFLOW. This cannot be overriden with ATTR_FORCE.

Signed-off-by: Seth Forshee <[email protected]>
Acked-by: Serge Hallyn <[email protected]>
Signed-off-by: Pavel Tikhomirov <[email protected]>
---
 fs/attr.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/fs/attr.c b/fs/attr.c
index 7262f3b..14c45f5 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -42,6 +42,17 @@ int inode_change_ok(const struct inode *inode, struct iattr 
*attr)
                        return error;
        }
 
+       /*
+        * Verify that uid/gid changes are valid in the target namespace
+        * of the superblock. This cannot be overriden using ATTR_FORCE.
+        */
+       if (ia_valid & ATTR_UID &&
+           from_kuid(inode->i_sb->s_user_ns, attr->ia_uid) == (uid_t)-1)
+               return -EOVERFLOW;
+       if (ia_valid & ATTR_GID &&
+           from_kgid(inode->i_sb->s_user_ns, attr->ia_gid) == (gid_t)-1)
+               return -EOVERFLOW;
+
        /* If force is set do it anyway. */
        if (ia_valid & ATTR_FORCE)
                return 0;
-- 
1.9.3

_______________________________________________
Devel mailing list
[email protected]
https://lists.openvz.org/mailman/listinfo/devel

Reply via email to