diff options
| author | Jussi Maki <joamaki@gmail.com> | 2021-05-19 15:47:42 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-06-03 08:38:12 +0200 |
| commit | 3a0363bf507dfd8a7c3cb8904561f2d20da66d76 (patch) | |
| tree | 66be3d5726f0a7e25d96afd7442bcda58d23c280 /net/core | |
| parent | 0f6e6872a7d819da81d2f92dd513ca7eae55369e (diff) | |
bpf: Set mac_len in bpf_skb_change_head
[ Upstream commit 84316ca4e100d8cbfccd9f774e23817cb2059868 ]
The skb_change_head() helper did not set "skb->mac_len", which is
problematic when it's used in combination with skb_redirect_peer().
Without it, redirecting a packet from a L3 device such as wireguard to
the veth peer device will cause skb->data to point to the middle of the
IP header on entry to tcp_v4_rcv() since the L2 header is not pulled
correctly due to mac_len=0.
Fixes: 3a0af8fd61f9 ("bpf: BPF for lightweight tunnel infrastructure")
Signed-off-by: Jussi Maki <joamaki@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210519154743.2554771-2-joamaki@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/filter.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 6272570fe139..01561268d216 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3020,6 +3020,7 @@ static inline int __bpf_skb_change_head(struct sk_buff *skb, u32 head_room, __skb_push(skb, head_room); memset(skb->data, 0, head_room); skb_reset_mac_header(skb); + skb_reset_mac_len(skb); } return ret; |