From b8fff748521c7178b9a7d32b5a34a81cec8396f3 Mon Sep 17 00:00:00 2001 From: Paul Chaignon Date: Mon, 25 Jul 2022 16:32:34 +0200 Subject: bpf: Set flow flag to allow any source IP in bpf_tunnel_key Commit 26101f5ab6bd ("bpf: Add source ip in "struct bpf_tunnel_key"") added support for getting and setting the outer source IP of encapsulated packets via the bpf_skb_{get,set}_tunnel_key BPF helper. This change allows BPF programs to set any IP address as the source, including for example the IP address of a container running on the same host. In that last case, however, the encapsulated packets are dropped when looking up the route because the source IP address isn't assigned to any interface on the host. To avoid this, we need to set the FLOWI_FLAG_ANYSRC flag. Fixes: 26101f5ab6bd ("bpf: Add source ip in "struct bpf_tunnel_key"") Signed-off-by: Paul Chaignon Signed-off-by: Daniel Borkmann Reviewed-by: Nikolay Aleksandrov Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/76873d384e21288abe5767551a0799ac93ec07fb.1658759380.git.paul@isovalent.com --- net/core/filter.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net') diff --git a/net/core/filter.c b/net/core/filter.c index 57c5e4c4efd2..dffc7dcda96a 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4653,6 +4653,7 @@ BPF_CALL_4(bpf_skb_set_tunnel_key, struct sk_buff *, skb, } else { info->key.u.ipv4.dst = cpu_to_be32(from->remote_ipv4); info->key.u.ipv4.src = cpu_to_be32(from->local_ipv4); + info->key.flow_flags = FLOWI_FLAG_ANYSRC; } return 0; -- cgit v1.2.3-70-g09d2 From bbd52178e249fe893ef4a9b87cde5b6c473b0a7c Mon Sep 17 00:00:00 2001 From: Joanne Koong Date: Fri, 22 Jul 2022 15:01:05 -0700 Subject: bpf: Fix bpf_xdp_pointer return pointer For the case where offset + len == size, bpf_xdp_pointer should return a valid pointer to the addr because that access is permitted. We should only return NULL in the case where offset + len exceeds size. Fixes: 3f364222d032 ("net: xdp: introduce bpf_xdp_pointer utility routine") Signed-off-by: Joanne Koong Signed-off-by: Daniel Borkmann Acked-by: Martin KaFai Lau Acked-by: Lorenzo Bianconi Link: https://lore.kernel.org/bpf/20220722220105.2065466-1-joannelkoong@gmail.com --- net/core/filter.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net') diff --git a/net/core/filter.c b/net/core/filter.c index dffc7dcda96a..5669248aff25 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3918,7 +3918,7 @@ static void *bpf_xdp_pointer(struct xdp_buff *xdp, u32 offset, u32 len) offset -= frag_size; } out: - return offset + len < size ? addr + offset : NULL; + return offset + len <= size ? addr + offset : NULL; } BPF_CALL_4(bpf_xdp_load_bytes, struct xdp_buff *, xdp, u32, offset, -- cgit v1.2.3-70-g09d2