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authorJohn Fastabend <john.r.fastabend@gmail.com>2017-10-19 09:03:52 -0700
committerDavid S. Miller <davem@davemloft.net>2017-10-22 00:54:09 +0100
commit8695a5395661fbb4a4f26c97f801f3800ae4754e (patch)
treed7f30a46a501e695325675205354a69c29bad81e
parent43ebf97fa40fc49242110d2bd50334fc6e95c802 (diff)
downloadlinux-sh-8695a5395661fbb4a4f26c97f801f3800ae4754e.tar.gz
bpf: devmap fix arithmetic overflow in bitmap_size calculation
An integer overflow is possible in dev_map_bitmap_size() when calculating the BITS_TO_LONG logic which becomes, after macro replacement, (((n) + (d) - 1)/ (d)) where 'n' is a __u32 and 'd' is (8 * sizeof(long)). To avoid overflow cast to u64 before arithmetic. Reported-by: Richard Weinberger <richard@nod.at> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--kernel/bpf/devmap.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 52e0548ba548..e745d6a88224 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -69,7 +69,7 @@ static LIST_HEAD(dev_map_list);
static u64 dev_map_bitmap_size(const union bpf_attr *attr)
{
- return BITS_TO_LONGS(attr->max_entries) * sizeof(unsigned long);
+ return BITS_TO_LONGS((u64) attr->max_entries) * sizeof(unsigned long);
}
static struct bpf_map *dev_map_alloc(union bpf_attr *attr)