← Back to team overview

kernel-packages team mailing list archive

[Bug 1566505] Re: User namespace mount updates

 

** Description changed:

- Bring xenial up to date wrt the current state of my upstream branch.
+ 
+ These commits bring xenial up to date wrt my branch for upstream. Most
+ of the changes here are in response to upstream feedback. At a high
+ level the changes are:
+ 
+  - A small improvement to the quota code, then disallow enabling quota
+    for mounts from non-init user namespaces. Since quota in non-init
+    namespaces isn't a requirement in 16.04 we're better off disabling it
+    until we know for sure how it will be handled upstream. However ext4
+    might temporarily enable quota during mount if recovering from an
+    unclean unmount, so the kernel needs to be able to handle it.
+ 
+  - Revert the way capabilities are determined for inodes in userns
+    mounts back to how it is upstream, i.e. based on both capabilities
+    and inode ownership, but allow a privileged user in s_user_ns to
+    chown if the id being changed is invalid and the other id is either
+    invalid or an id mapped into s_user_ns. This gives the mounter
+    control over inodes with unmappable ids while making it safe to have
+    s_user_ns != &init_user_ns for proc and kernfs-based mounts.
+ 
+  - Fix an incompatibility between cgroup namespaces and user namespace
+    mounts. Previously this was fixed as a side effect of another patch,
+    but that patch is being reverted.
+ 
+  - Remove a needless mount option initialization in fuse.
+ 
+  - Fix a resource leak for an error path in sget_userns().

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1566505

Title:
  User namespace mount updates

Status in linux package in Ubuntu:
  In Progress
Status in linux source package in Xenial:
  In Progress

Bug description:
  
  These commits bring xenial up to date wrt my branch for upstream. Most
  of the changes here are in response to upstream feedback. At a high
  level the changes are:

   - A small improvement to the quota code, then disallow enabling quota
     for mounts from non-init user namespaces. Since quota in non-init
     namespaces isn't a requirement in 16.04 we're better off disabling it
     until we know for sure how it will be handled upstream. However ext4
     might temporarily enable quota during mount if recovering from an
     unclean unmount, so the kernel needs to be able to handle it.

   - Revert the way capabilities are determined for inodes in userns
     mounts back to how it is upstream, i.e. based on both capabilities
     and inode ownership, but allow a privileged user in s_user_ns to
     chown if the id being changed is invalid and the other id is either
     invalid or an id mapped into s_user_ns. This gives the mounter
     control over inodes with unmappable ids while making it safe to have
     s_user_ns != &init_user_ns for proc and kernfs-based mounts.

   - Fix an incompatibility between cgroup namespaces and user namespace
     mounts. Previously this was fixed as a side effect of another patch,
     but that patch is being reverted.

   - Remove a needless mount option initialization in fuse.

   - Fix a resource leak for an error path in sget_userns().

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1566505/+subscriptions


References