From 87cebd0f198b3f1153e5aa8d63acf18c4d61af87 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Thu, 25 May 2017 01:05:08 +0200 Subject: [PATCH] bpf: fix wrong exposure of map_flags into fdinfo for lpm [ Upstream commit a316338cb71a3260201490e615f2f6d5c0d8fb2c ] trie_alloc() always needs to have BPF_F_NO_PREALLOC passed in via attr->map_flags, since it does not support preallocation yet. We check the flag, but we never copy the flag into trie->map.map_flags, which is later on exposed into fdinfo and used by loaders such as iproute2. Latter uses this in bpf_map_selfcheck_pinned() to test whether a pinned map has the same spec as the one from the BPF obj file and if not, bails out, which is currently the case for lpm since it exposes always 0 as flags. Also copy over flags in array_map_alloc() and stack_map_alloc(). They always have to be 0 right now, but we should make sure to not miss to copy them over at a later point in time when we add actual flags for them to use. Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation") Reported-by: Jarno Rajahalme Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- kernel/bpf/arraymap.c | 1 + kernel/bpf/lpm_trie.c | 1 + kernel/bpf/stackmap.c | 1 + 3 files changed, 3 insertions(+) diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 6b6f41f0b2116..892f47c283776 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -83,6 +83,7 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr) array->map.key_size = attr->key_size; array->map.value_size = attr->value_size; array->map.max_entries = attr->max_entries; + array->map.map_flags = attr->map_flags; array->elem_size = elem_size; if (!percpu) diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c index b37bd9ab7f574..7ab9e42180abb 100644 --- a/kernel/bpf/lpm_trie.c +++ b/kernel/bpf/lpm_trie.c @@ -432,6 +432,7 @@ static struct bpf_map *trie_alloc(union bpf_attr *attr) trie->map.key_size = attr->key_size; trie->map.value_size = attr->value_size; trie->map.max_entries = attr->max_entries; + trie->map.map_flags = attr->map_flags; trie->data_size = attr->key_size - offsetof(struct bpf_lpm_trie_key, data); trie->max_prefixlen = trie->data_size * 8; diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 22aa45cd0324e..96f6043176856 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -88,6 +88,7 @@ static struct bpf_map *stack_map_alloc(union bpf_attr *attr) smap->map.key_size = attr->key_size; smap->map.value_size = value_size; smap->map.max_entries = attr->max_entries; + smap->map.map_flags = attr->map_flags; smap->n_buckets = n_buckets; smap->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT; -- 2.47.2