From: Waiman Long Date: Sat, 21 Feb 2026 18:54:12 +0000 (-0500) Subject: cgroup/cpuset: Fix incorrect use of cpuset_update_tasks_cpumask() in update_cpumasks_... X-Git-Tag: v7.0-rc3~46^2~7 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=68230aac8b9aad243626fbaf3ca170012c17fec5;p=thirdparty%2Fkernel%2Flinux.git cgroup/cpuset: Fix incorrect use of cpuset_update_tasks_cpumask() in update_cpumasks_hier() Commit e2ffe502ba45 ("cgroup/cpuset: Add cpuset.cpus.exclusive for v2") incorrectly changed the 2nd parameter of cpuset_update_tasks_cpumask() from tmp->new_cpus to cp->effective_cpus. This second parameter is just a temporary cpumask for internal use. The cpuset_update_tasks_cpumask() function was originally called update_tasks_cpumask() before commit 381b53c3b549 ("cgroup/cpuset: rename functions shared between v1 and v2"). This mistake can incorrectly change the effective_cpus of the cpuset when it is the top_cpuset or in arm64 architecture where task_cpu_possible_mask() may differ from cpu_possible_mask. So far top_cpuset hasn't been passed to update_cpumasks_hier() yet, but arm64 arch can still be impacted. Fix it by reverting the incorrect change. Fixes: e2ffe502ba45 ("cgroup/cpuset: Add cpuset.cpus.exclusive for v2") Signed-off-by: Waiman Long Signed-off-by: Tejun Heo --- diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index a366ef84f982..8dfffe2dc9ed 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -2157,7 +2157,7 @@ get_css: WARN_ON(!is_in_v2_mode() && !cpumask_equal(cp->cpus_allowed, cp->effective_cpus)); - cpuset_update_tasks_cpumask(cp, cp->effective_cpus); + cpuset_update_tasks_cpumask(cp, tmp->new_cpus); /* * On default hierarchy, inherit the CS_SCHED_LOAD_BALANCE