From bdab18633a302c82b5e5d5dbc4e38b0baf9c0837 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 20 Sep 2026 08:15:23 -0700 Subject: Merge tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull futex fix from Ingo Molnar: - Also allocate a default private futex hash on vfork() as well, to avoid races with (private) futex waiters (Peter Zijlstra) * tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Also allocate private hash on vfork() --- .../admin-guide/namespaces/resource-control.rst | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) create mode 100644 Documentation/admin-guide/namespaces/resource-control.rst (limited to 'Documentation/admin-guide/namespaces/resource-control.rst') diff --git a/Documentation/admin-guide/namespaces/resource-control.rst b/Documentation/admin-guide/namespaces/resource-control.rst new file mode 100644 index 000000000..553a44803 --- /dev/null +++ b/Documentation/admin-guide/namespaces/resource-control.rst @@ -0,0 +1,18 @@ +==================================== +User namespaces and resource control +==================================== + +The kernel contains many kinds of objects that either don't have +individual limits or that have limits which are ineffective when +a set of processes is allowed to switch their UID. On a system +where the admins don't trust their users or their users' programs, +user namespaces expose the system to potential misuse of resources. + +In order to mitigate this, we recommend that admins enable memory +control groups on any system that enables user namespaces. +Furthermore, we recommend that admins configure the memory control +groups to limit the maximum memory usable by any untrusted user. + +Memory control groups can be configured by installing the libcgroup +package present on most distros editing /etc/cgrules.conf, +/etc/cgconfig.conf and setting up libpam-cgroup. -- cgit v1.3.1