1 files changed, 28 insertions, 8 deletions

diff --git a/fs/attr.c b/fs/attr.c
index 12ffdb6fb63c..d0b4d34878fb 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -18,6 +18,32 @@
 #include <linux/evm.h>
 #include <linux/ima.h>
 
+static bool chown_ok(const struct inode *inode, kuid_t uid)
+{
+        if (uid_eq(current_fsuid(), inode->i_uid) &&
+            uid_eq(uid, inode->i_uid))
+                return true;
+        if (capable_wrt_inode_uidgid(inode, CAP_CHOWN))
+                return true;
+        if (uid_eq(inode->i_uid, INVALID_UID) &&
+            ns_capable(inode->i_sb->s_user_ns, CAP_CHOWN))
+                return true;
+        return false;
+}
+
+static bool chgrp_ok(const struct inode *inode, kgid_t gid)
+{
+        if (uid_eq(current_fsuid(), inode->i_uid) &&
+            (in_group_p(gid) || gid_eq(gid, inode->i_gid)))
+                return true;
+        if (capable_wrt_inode_uidgid(inode, CAP_CHOWN))
+                return true;
+        if (gid_eq(inode->i_gid, INVALID_GID) &&
+            ns_capable(inode->i_sb->s_user_ns, CAP_CHOWN))
+                return true;
+        return false;
+}
+
 /**
  * setattr_prepare - check if attribute changes to a dentry are allowed
  * @dentry:     dentry to check
@@ -52,17 +78,11 @@ int setattr_prepare(struct dentry *dentry, struct iattr *attr)
                 goto kill_priv;
 
         /* Make sure a caller can chown. */
-        if ((ia_valid & ATTR_UID) &&
-            (!uid_eq(current_fsuid(), inode->i_uid) ||
-             !uid_eq(attr->ia_uid, inode->i_uid)) &&
-            !capable_wrt_inode_uidgid(inode, CAP_CHOWN))
+        if ((ia_valid & ATTR_UID) && !chown_ok(inode, attr->ia_uid))
                 return -EPERM;
 
         /* Make sure caller can chgrp. */
-        if ((ia_valid & ATTR_GID) &&
-            (!uid_eq(current_fsuid(), inode->i_uid) ||
-            (!in_group_p(attr->ia_gid) && !gid_eq(attr->ia_gid, inode->i_gid))) &&
-            !capable_wrt_inode_uidgid(inode, CAP_CHOWN))
+        if ((ia_valid & ATTR_GID) && !chgrp_ok(inode, attr->ia_gid))
                 return -EPERM;
 
         /* Make sure a caller can chmod. */