diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/core.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 8b791e9e9f67..3cc6fb1d2054 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -10909,8 +10909,19 @@ static void mm_cid_fixup_cpus_to_tasks(struct mm_struct *mm) } else if (rq->curr->mm == mm && rq->curr->mm_cid.active) { unsigned int cid = rq->curr->mm_cid.cid; - /* Ensure it has the transition bit set */ - if (!cid_in_transit(cid)) { + /* + * Set the transition bit only on a genuine task-owned + * CID. A running active task can legitimately have + * MM_CID_UNSET here: in per-CPU mode CIDs are assigned + * lazily on schedule-in, so the fork()/execve() window + * leaves the task active with no owned CID. Setting the + * transition bit on MM_CID_UNSET would later feed + * clear_bit() an out-of-bounds bit number via + * mm_cid_schedout(), so exclude it. A CPU-owned + * (MM_CID_ONCPU) CID is handled by the cid_on_cpu() + * branch above and never reaches here. + */ + if (cid != MM_CID_UNSET && !cid_in_transit(cid)) { cid = cid_to_transit_cid(cid); rq->curr->mm_cid.cid = cid; pcp->cid = cid; |