Merge tag 'bitmap-for-6.17-rc5' of https://github.com/norov/linux

Pull bitmap fix from Yury Norov:
 "Fix sched_numa_find_nth_cpu() if mask offline

  sched_numa_find_nth_cpu() uses a bsearch to look for the 'closest' CPU
  in sched_domains_numa_masks and given cpus mask. However they might
  not intersect if all CPUs in the cpus mask are offline.

  bsearch will return NULL in that case, bail out instead of
  dereferencing a bogus pointer"

* tag 'bitmap-for-6.17-rc5' of https://github.com/norov/linux:
  sched: Fix sched_numa_find_nth_cpu() if mask offline

Author: torvalds

kernel/sched/topology.c

@@ -2201,6 +2201,8 @@ int sched_numa_find_nth_cpu(const struct cpumask *cpus, int cpu, int node)
 		goto unlock;
 
 	hop_masks = bsearch(&k, k.masks, sched_domains_numa_levels, sizeof(k.masks[0]), hop_cmp);
+	if (!hop_masks)
+		goto unlock;
 	hop = hop_masks	- k.masks;
 
 	ret = hop ?