From: Toke Høiland-Jørgensen Date: Tue, 16 Jun 2020 14:28:29 +0000 (+0200) Subject: devmap: Use bpf_map_area_alloc() for allocating hash buckets X-Git-Tag: v5.8-rc3~34^2~77^2~3 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=99c51064fb06146b3d494b745c947e438a10aaa7;p=users%2Fjedix%2Flinux-maple.git devmap: Use bpf_map_area_alloc() for allocating hash buckets Syzkaller discovered that creating a hash of type devmap_hash with a large number of entries can hit the memory allocator limit for allocating contiguous memory regions. There's really no reason to use kmalloc_array() directly in the devmap code, so just switch it to the existing bpf_map_area_alloc() function that is used elsewhere. Fixes: 6f9d451ab1a3 ("xdp: Add devmap_hash map type for looking up devices by hashed index") Reported-by: Xiumei Mu Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Alexei Starovoitov Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20200616142829.114173-1-toke@redhat.com --- diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index 0cbb72cdaf63..5fdbc776a760 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -86,12 +86,13 @@ static DEFINE_PER_CPU(struct list_head, dev_flush_list); static DEFINE_SPINLOCK(dev_map_lock); static LIST_HEAD(dev_map_list); -static struct hlist_head *dev_map_create_hash(unsigned int entries) +static struct hlist_head *dev_map_create_hash(unsigned int entries, + int numa_node) { int i; struct hlist_head *hash; - hash = kmalloc_array(entries, sizeof(*hash), GFP_KERNEL); + hash = bpf_map_area_alloc(entries * sizeof(*hash), numa_node); if (hash != NULL) for (i = 0; i < entries; i++) INIT_HLIST_HEAD(&hash[i]); @@ -145,7 +146,8 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr) return -EINVAL; if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) { - dtab->dev_index_head = dev_map_create_hash(dtab->n_buckets); + dtab->dev_index_head = dev_map_create_hash(dtab->n_buckets, + dtab->map.numa_node); if (!dtab->dev_index_head) goto free_charge; @@ -232,7 +234,7 @@ static void dev_map_free(struct bpf_map *map) } } - kfree(dtab->dev_index_head); + bpf_map_area_free(dtab->dev_index_head); } else { for (i = 0; i < dtab->map.max_entries; i++) { struct bpf_dtab_netdev *dev;