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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: [RFC bpf-next v3 3/8] flow_dissector: fix clamping of BPF flow_keys for non-zero nhoff
Date: Fri, 22 Mar 2019 12:58:58 -0700	[thread overview]
Message-ID: <20190322195903.162516-4-sdf@google.com> (raw)
In-Reply-To: <20190322195903.162516-1-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 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 0dac3382e841..3b35fc35f583 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -716,7 +716,7 @@ bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
 
 	result = BPF_PROG_RUN(prog, ctx);
 
-	flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, 0, hlen);
+	flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, nhoff, hlen);
 	flow_keys->thoff = clamp_t(u16, flow_keys->thoff,
 				   flow_keys->nhoff, hlen);
 
-- 
2.21.0.392.gf8f6787159e-goog


  parent reply	other threads:[~2019-03-22 19:59 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-22 19:58 [RFC bpf-next v3 0/8] net: flow_dissector: trigger BPF hook when called from eth_get_headlen Stanislav Fomichev
2019-03-22 19:58 ` [RFC bpf-next v3 1/8] flow_dissector: allow access only to a subset of __sk_buff fields Stanislav Fomichev
2019-03-22 19:58 ` [RFC bpf-next v3 2/8] flow_dissector: switch kernel context to struct bpf_flow_dissector Stanislav Fomichev
2019-03-22 19:58 ` Stanislav Fomichev [this message]
2019-03-22 19:58 ` [RFC bpf-next v3 4/8] bpf: when doing BPF_PROG_TEST_RUN for flow dissector use no-skb mode Stanislav Fomichev
2019-03-22 19:59 ` [RFC bpf-next v3 5/8] net: plumb network namespace into __skb_flow_dissect Stanislav Fomichev
2019-03-22 19:59 ` [RFC bpf-next v3 6/8] flow_dissector: handle no-skb use case Stanislav Fomichev
2019-03-23  1:00   ` Alexei Starovoitov
2019-03-23  1:19     ` Stanislav Fomichev
2019-03-23  1:41       ` Alexei Starovoitov
2019-03-23 16:05         ` Stanislav Fomichev
2019-03-26  0:35           ` Alexei Starovoitov
2019-03-26 16:45             ` Stanislav Fomichev
2019-03-26 17:48               ` Alexei Starovoitov
2019-03-26 17:51                 ` Willem de Bruijn
2019-03-26 18:08                   ` Alexei Starovoitov
2019-03-26 18:17                     ` Stanislav Fomichev
2019-03-26 18:30                       ` Alexei Starovoitov
2019-03-26 18:54                         ` Stanislav Fomichev
2019-03-27  1:41                           ` Alexei Starovoitov
2019-03-27  2:44                             ` Stanislav Fomichev
2019-03-27 17:55                               ` Alexei Starovoitov
2019-03-27 19:58                                 ` Stanislav Fomichev
2019-03-28  1:26                                   ` Alexei Starovoitov
2019-03-28  3:14                                     ` Willem de Bruijn
2019-03-28  3:32                                       ` Alexei Starovoitov
2019-03-28  4:17                                         ` Stanislav Fomichev
2019-03-28 12:58                                           ` Willem de Bruijn
2019-04-01 16:30                                             ` Stanislav Fomichev
2019-03-22 19:59 ` [RFC bpf-next v3 7/8] net: pass net argument to the eth_get_headlen Stanislav Fomichev
2019-03-22 19:59 ` [RFC bpf-next v3 8/8] selftests/bpf: add flow dissector bpf_skb_load_bytes helper test Stanislav Fomichev

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