From 851a723e45d1c4c8f6f7b0d2cfbc5f53690bb4e9 Mon Sep 17 00:00:00 2001 From: Waiman Long Date: Thu, 22 Sep 2022 14:00:41 -0400 Subject: [PATCH] sched: Always clear user_cpus_ptr in do_set_cpus_allowed() The do_set_cpus_allowed() function is used by either kthread_bind() or select_fallback_rq(). In both cases the user affinity (if any) should be destroyed too. Suggested-by: Peter Zijlstra Signed-off-by: Waiman Long Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20220922180041.1768141-6-longman@redhat.com --- kernel/sched/core.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 283bdbd8c3c1..87c9cdf37a26 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2593,14 +2593,20 @@ __do_set_cpus_allowed(struct task_struct *p, struct affinity_context *ctx) set_next_task(rq, p); } +/* + * Used for kthread_bind() and select_fallback_rq(), in both cases the user + * affinity (if any) should be destroyed too. + */ void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) { struct affinity_context ac = { .new_mask = new_mask, - .flags = 0, + .user_mask = NULL, + .flags = SCA_USER, /* clear the user requested mask */ }; __do_set_cpus_allowed(p, &ac); + kfree(ac.user_mask); } int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, -- 2.42.0