From: Toke Høiland-Jørgensen toke@redhat.com
[ Upstream commit 99c51064fb06146b3d494b745c947e438a10aaa7 ]
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 xmu@redhat.com Signed-off-by: Toke Høiland-Jørgensen toke@redhat.com Signed-off-by: Alexei Starovoitov ast@kernel.org Acked-by: John Fastabend john.fastabend@gmail.com Link: https://lore.kernel.org/bpf/20200616142829.114173-1-toke@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/bpf/devmap.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index b4b6b77f309c6..6684696fa4571 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -88,12 +88,13 @@ struct bpf_dtab { 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]); @@ -151,7 +152,8 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr) INIT_LIST_HEAD(per_cpu_ptr(dtab->flush_list, cpu));
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_percpu;
@@ -249,7 +251,7 @@ 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;