devmap: Use bpf_map_area_alloc() for allocating hash buckets
[ Upstream commit5.4-rM2-2.2.x-imx-squashed99c51064fb
] 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:6f9d451ab1
("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>
parent
b93df0f6d7
commit
0f3aa6c6d6
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@ -88,12 +88,13 @@ struct bpf_dtab {
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static DEFINE_SPINLOCK(dev_map_lock);
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static DEFINE_SPINLOCK(dev_map_lock);
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static LIST_HEAD(dev_map_list);
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static LIST_HEAD(dev_map_list);
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static struct hlist_head *dev_map_create_hash(unsigned int entries)
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static struct hlist_head *dev_map_create_hash(unsigned int entries,
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int numa_node)
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{
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{
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int i;
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int i;
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struct hlist_head *hash;
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struct hlist_head *hash;
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hash = kmalloc_array(entries, sizeof(*hash), GFP_KERNEL);
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hash = bpf_map_area_alloc(entries * sizeof(*hash), numa_node);
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if (hash != NULL)
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if (hash != NULL)
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for (i = 0; i < entries; i++)
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for (i = 0; i < entries; i++)
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INIT_HLIST_HEAD(&hash[i]);
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INIT_HLIST_HEAD(&hash[i]);
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@ -151,7 +152,8 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
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INIT_LIST_HEAD(per_cpu_ptr(dtab->flush_list, cpu));
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INIT_LIST_HEAD(per_cpu_ptr(dtab->flush_list, cpu));
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if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
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if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
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dtab->dev_index_head = dev_map_create_hash(dtab->n_buckets);
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dtab->dev_index_head = dev_map_create_hash(dtab->n_buckets,
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dtab->map.numa_node);
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if (!dtab->dev_index_head)
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if (!dtab->dev_index_head)
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goto free_percpu;
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goto free_percpu;
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@ -249,7 +251,7 @@ static void dev_map_free(struct bpf_map *map)
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}
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}
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}
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}
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kfree(dtab->dev_index_head);
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bpf_map_area_free(dtab->dev_index_head);
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} else {
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} else {
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for (i = 0; i < dtab->map.max_entries; i++) {
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for (i = 0; i < dtab->map.max_entries; i++) {
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struct bpf_dtab_netdev *dev;
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struct bpf_dtab_netdev *dev;
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