Revert "UBUNTU: SAUCE: (namespace) fs: Don't remove suid for CAP_FSETID for userns...

BugLink: https://bugs.launchpad.net/bugs/1644165
This reverts commit bd088daefbc5cd42c57c6661e0b95b35d4af3755.

The kernel fix for bug #1634964 breaks LXD userspace, in particular the
following commits:

ac7f3f73cb39 (namespace) vfs: Don't modify inodes with a uid or gid unknown to the vfs
ca52383ad6a6 (namespace) vfs: Don't create inodes with a uid or gid unknown to the vfs

LXD 2.0.6 will include changes to support these kernel changes, but it isn't
available yet on xenial, so for now we just revert these commits.

Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

diff --git a/fs/inode.c b/fs/inode.c
index 037e2f42852bf232fff45af86978e010c18673c2..07453fb3c88d6efc0029170cdd50895a36e4c0b3 100644 (file)
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1677,8 +1677,7 @@ EXPORT_SYMBOL(touch_atime);
  */
 int should_remove_suid(struct dentry *dentry)
 {
-       struct inode *inode = d_inode(dentry);
-       umode_t mode = inode->i_mode;
+       umode_t mode = d_inode(dentry)->i_mode;
        int kill = 0;
 
        /* suid always must be killed */
@@ -1692,8 +1691,7 @@ int should_remove_suid(struct dentry *dentry)
        if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))
                kill |= ATTR_KILL_SGID;
 
-       if (unlikely(kill && !capable_wrt_inode_uidgid(inode, CAP_FSETID) &&
-                    S_ISREG(mode)))
+       if (unlikely(kill && !capable(CAP_FSETID) && S_ISREG(mode)))
                return kill;
 
        return 0;