diff options
| author | Florian Lehner <dev@der-flo.net> | 2024-06-15 12:11:58 +0200 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2024-07-02 19:05:25 +0200 |
| commit | fd8db07705c55a995c42b1e71afc42faad675b0b (patch) | |
| tree | 4d34c44961bff74ce51e3f587b2a680d958eb6dd | |
| parent | 69716e44a74af464060faa68fa2b54f3af03c16a (diff) | |
bpf, devmap: Add .map_alloc_check
Use the .map_allock_check callback to perform allocation checks before
allocating memory for the devmap.
Signed-off-by: Florian Lehner <dev@der-flo.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240615101158.57889-1-dev@der-flo.net
| -rw-r--r-- | kernel/bpf/devmap.c | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index 7f3b34452243..da1fec906b96 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -107,7 +107,7 @@ static inline struct hlist_head *dev_map_index_hash(struct bpf_dtab *dtab, return &dtab->dev_index_head[idx & (dtab->n_buckets - 1)]; } -static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr) +static int dev_map_alloc_check(union bpf_attr *attr) { u32 valsize = attr->value_size; @@ -121,23 +121,28 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr) attr->map_flags & ~DEV_CREATE_FLAG_MASK) return -EINVAL; + if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) { + /* Hash table size must be power of 2; roundup_pow_of_two() + * can overflow into UB on 32-bit arches + */ + if (attr->max_entries > 1UL << 31) + return -EINVAL; + } + + return 0; +} + +static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr) +{ /* Lookup returns a pointer straight to dev->ifindex, so make sure the * verifier prevents writes from the BPF side */ attr->map_flags |= BPF_F_RDONLY_PROG; - - bpf_map_init_from_attr(&dtab->map, attr); if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) { - /* hash table size must be power of 2; roundup_pow_of_two() can - * overflow into UB on 32-bit arches, so check that first - */ - if (dtab->map.max_entries > 1UL << 31) - return -EINVAL; - + /* Hash table size must be power of 2 */ dtab->n_buckets = roundup_pow_of_two(dtab->map.max_entries); - dtab->dev_index_head = dev_map_create_hash(dtab->n_buckets, dtab->map.numa_node); if (!dtab->dev_index_head) @@ -1040,6 +1045,7 @@ static u64 dev_map_mem_usage(const struct bpf_map *map) BTF_ID_LIST_SINGLE(dev_map_btf_ids, struct, bpf_dtab) const struct bpf_map_ops dev_map_ops = { .map_meta_equal = bpf_map_meta_equal, + .map_alloc_check = dev_map_alloc_check, .map_alloc = dev_map_alloc, .map_free = dev_map_free, .map_get_next_key = dev_map_get_next_key, @@ -1054,6 +1060,7 @@ const struct bpf_map_ops dev_map_ops = { const struct bpf_map_ops dev_map_hash_ops = { .map_meta_equal = bpf_map_meta_equal, + .map_alloc_check = dev_map_alloc_check, .map_alloc = dev_map_alloc, .map_free = dev_map_free, .map_get_next_key = dev_map_hash_get_next_key, |