[GIT PULL] cgroup: Fixes for v6.17-rc6

From: Tejun Heo

Date: Wed Sep 17 2025 - 15:23:00 EST


The following changes since commit 6563623e604e3e235b2cee71190a4972be8f986b:

docs: cgroup: fixed spelling mistakes in documentation (2025-08-12 10:52:28 -1000)

are available in the Git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git/ tags/cgroup-for-6.17-rc6-fixes

for you to fetch changes up to 94a4acfec14615e971eb2c9e1fa6c992c85ff6c6:

cgroup/psi: Set of->priv to NULL upon file release (2025-08-22 07:47:43 -1000)

----------------------------------------------------------------
cgroup: Fixes for v6.17-rc6

This contains two cgroup changes. Both are pretty low risk.

- Fix deadlock in cgroup destruction when repeatedly mounting/unmounting
perf_event and net_prio controllers. The issue occurs because
cgroup_destroy_wq has max_active=1, causing root destruction to wait for
CSS offline operations that are queued behind it. The fix splits
cgroup_destroy_wq into three separate workqueues to eliminate the
blocking.

- Set of->priv to NULL upon file release to make potential bugs to manifest
as NULL pointer dereferences rather than use-after-free errors.

----------------------------------------------------------------
Chen Ridong (2):
cgroup: split cgroup_destroy_wq into 3 workqueues
cgroup/psi: Set of->priv to NULL upon file release

kernel/cgroup/cgroup.c | 44 +++++++++++++++++++++++++++++++++++++-------
1 file changed, 37 insertions(+), 7 deletions(-)

--
tejun