diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c index cc9597a877707f3de6e7bbfdec3d3c7ae9f56fbc..d1c4e1f3be2c71385e5c4414b8c831e4b2e4a91d 100644 --- a/net/core/bpf_sk_storage.c +++ b/net/core/bpf_sk_storage.c @@ -633,7 +633,8 @@ static struct bpf_map *bpf_sk_storage_map_alloc(union bpf_attr *attr) return ERR_PTR(-ENOMEM); bpf_map_init_from_attr(&smap->map, attr); - smap->bucket_log = ilog2(roundup_pow_of_two(num_possible_cpus())); + /* Use at least 2 buckets, select_bucket() is undefined behavior with 1 bucket */ + smap->bucket_log = max_t(u32, 1, ilog2(roundup_pow_of_two(num_possible_cpus()))); nbuckets = 1U << smap->bucket_log; smap->buckets = kvcalloc(sizeof(*smap->buckets), nbuckets, GFP_USER | __GFP_NOWARN);