The __per_cpu_offset[] array has "nr_cpu_ids" elements so change the > >= to prevent a read one element beyond the end of the array. Fixes: 0504bc41a62c ("kernel/smp: Provide CSD lock timeout diagnostics") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> --- kernel/smp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/smp.c b/kernel/smp.c index 78b602cae6c2..f49966713ac3 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -171,7 +171,7 @@ static __always_inline bool csd_lock_wait_toolong(call_single_data_t *csd, u64 t *bug_id = atomic_inc_return(&csd_bug_count); cpu = csd_lock_wait_getcpu(csd); smp_mb(); // No stale cur_csd values! - if (WARN_ONCE(cpu < 0 || cpu > nr_cpu_ids, "%s: cpu = %d\n", __func__, cpu)) + if (WARN_ONCE(cpu < 0 || cpu >= nr_cpu_ids, "%s: cpu = %d\n", __func__, cpu)) cpu_cur_csd = READ_ONCE(per_cpu(cur_csd, 0)); else cpu_cur_csd = READ_ONCE(per_cpu(cur_csd, cpu)); -- 2.27.0