From: Stanislav Fomichev <sdf@google.com>
To: netdev@vger.kernel.org, bpf@vger.kernel.org
Cc: davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net,
simon.horman@netronome.com, willemb@google.com,
peterpenkov96@gmail.com, Stanislav Fomichev <sdf@google.com>
Subject: [PATCH bpf 3/5] flow_dissector: fix clamping of BPF flow_keys for non-zero nhoff
Date: Mon, 1 Apr 2019 13:57:32 -0700 [thread overview]
Message-ID: <20190401205734.4400-4-sdf@google.com> (raw)
In-Reply-To: <20190401205734.4400-1-sdf@google.com>
Don't allow BPF program to set flow_keys->nhoff to less than initial
value. We currently don't read the value afterwards in anything but
the tests, but it's still a good practice to return consistent
values to the test programs.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
net/core/flow_dissector.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 9b84250039df..94a450b2191a 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -717,7 +717,8 @@ bool __skb_flow_bpf_dissect(struct bpf_prog *prog,
/* Restore state */
memcpy(cb, &cb_saved, sizeof(cb_saved));
- flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, 0, skb->len);
+ flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff,
+ skb_network_offset(skb), skb->len);
flow_keys->thoff = clamp_t(u16, flow_keys->thoff,
flow_keys->nhoff, skb->len);
--
2.21.0.392.gf8f6787159e-goog
next prev parent reply other threads:[~2019-04-01 20:57 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-01 20:57 [PATCH bpf 0/5] flow_dissector: lay groundwork for calling BPF hook from eth_get_headlen Stanislav Fomichev
2019-04-01 20:57 ` [PATCH bpf 1/5] selftests/bpf: fix vlan handling in flow dissector program Stanislav Fomichev
2019-04-01 20:57 ` [PATCH bpf 2/5] net/flow_dissector: pass flow_keys->n_proto to BPF programs Stanislav Fomichev
2019-04-01 20:57 ` Stanislav Fomichev [this message]
2019-04-01 20:57 ` [PATCH bpf 4/5] flow_dissector: allow access only to a subset of __sk_buff fields Stanislav Fomichev
2019-04-01 20:57 ` [PATCH bpf 5/5] flow_dissector: document BPF flow dissector environment Stanislav Fomichev
2019-04-02 20:54 ` Petar Penkov
2019-04-02 21:00 ` Stanislav Fomichev
2019-04-03 18:34 ` Jesper Dangaard Brouer
2019-04-03 18:50 ` Stanislav Fomichev
2019-04-02 20:17 ` [PATCH bpf 0/5] flow_dissector: lay groundwork for calling BPF hook from eth_get_headlen Willem de Bruijn
2019-04-02 20:52 ` Petar Penkov
2019-04-03 14:54 ` Daniel Borkmann
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