[GIT PULL] cgroup: Fixes for v7.3-rc6

[GIT PULL] cgroup: Fixes for v7.3-rc6

[Tejun Heo]

Hello,

The following changes since commit 31c88350b7dd1522792f726f79607f31bb55c50f:

  cgroup/cpuset: Return PERR_NOCPUS in remote_partition_enable() on subpartitions_cpus conflict (2026-09-26 08:07:26 -1000)

are available in the Git repository at:

  https://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git tags/cgroup-for-7.3-rc6-fixes

for you to fetch changes up to b8eb5fd5bdb4c03758b056c70e5e1d962ca89757:

  cgroup/cpuset: Call is_in_v2_mode() after acquiring cpuset_mutex in cpuset_handle_hotplug() (2026-10-06 06:36:51 -1000)

----------------------------------------------------------------
cgroup: Fixes for v7.3-rc6

- During CPU offline, the active mask drops the CPU before cpuset updates
  the effective CPUs, so a task placement in that window could find no
  active CPU in the top cpuset and dereference NULL. Restore the NULL check.

- The cpuset v2-mode test read the subsystem's root pointer, which is stale
  during a cgroup filesystem rebind, and the hotplug handler evaluated it
  before taking the cpuset mutex. Record the mode in a flag and test it
  under the mutex.

----------------------------------------------------------------
Waiman Long (3):
      cgroup/cpuset: Don't access cpuset_cgrp_subsys.root in is_in_v2_mode()
      cgroup/cpuset: Handle cpu hotplug race in guarantee_active_cpus()
      cgroup/cpuset: Call is_in_v2_mode() after acquiring cpuset_mutex in cpuset_handle_hotplug()

 kernel/cgroup/cpuset.c | 40 ++++++++++++++++++++++++++++++++--------
 1 file changed, 32 insertions(+), 8 deletions(-)

-- 
tejun