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| author | Stanislav Fomichev <sdf@google.com> | 2019-04-01 23:57:32 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2019-04-03 17:49:48 +0300 |
| commit | b9e9c8599f0f23e3d2051befc9966a84b639f64f (patch) | |
| tree | b602fe9bf2d1826282b3a9467d401d41d3ae5c61 | |
| parent | 822fe61795018265ae14731d4e5399e5bde36864 (diff) | |
| download | linux-b9e9c8599f0f23e3d2051befc9966a84b639f64f.tar.xz | |
flow_dissector: fix clamping of BPF flow_keys for non-zero nhoff
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>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| -rw-r--r-- | net/core/flow_dissector.c | 3 |
1 files changed, 2 insertions, 1 deletions
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); |