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| author | Jakub Sitnicki <jakub@cloudflare.com> | 2022-02-09 19:43:32 +0100 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-02-09 11:40:45 -0800 |
| commit | 9a69e2b385f443f244a7e8b8bcafe5ccfb0866b4 (patch) | |
| tree | 22d7aa445e1664fd4ecbd2a0ad3c8eaef0cf84af /net/core/filter.c | |
| parent | dc37dc617fabfb1c3a16d49f5d8cc20e9e3608ca (diff) | |
| download | linux-9a69e2b385f443f244a7e8b8bcafe5ccfb0866b4.tar.gz linux-9a69e2b385f443f244a7e8b8bcafe5ccfb0866b4.tar.bz2 linux-9a69e2b385f443f244a7e8b8bcafe5ccfb0866b4.zip | |
bpf: Make remote_port field in struct bpf_sk_lookup 16-bit wide
remote_port is another case of a BPF context field documented as a 32-bit
value in network byte order for which the BPF context access converter
generates a load of a zero-padded 16-bit integer in network byte order.
First such case was dst_port in bpf_sock which got addressed in commit
4421a582718a ("bpf: Make dst_port field in struct bpf_sock 16-bit wide").
Loading 4-bytes from the remote_port offset and converting the value with
bpf_ntohl() leads to surprising results, as the expected value is shifted
by 16 bits.
Reduce the confusion by splitting the field in two - a 16-bit field holding
a big-endian integer, and a 16-bit zero-padding anonymous field that
follows it.
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220209184333.654927-2-jakub@cloudflare.com
Diffstat (limited to 'net/core/filter.c')
| -rw-r--r-- | net/core/filter.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 99a05199a806..83f06d3b2c52 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -10843,7 +10843,8 @@ static bool sk_lookup_is_valid_access(int off, int size, case bpf_ctx_range(struct bpf_sk_lookup, local_ip4): case bpf_ctx_range_till(struct bpf_sk_lookup, remote_ip6[0], remote_ip6[3]): case bpf_ctx_range_till(struct bpf_sk_lookup, local_ip6[0], local_ip6[3]): - case bpf_ctx_range(struct bpf_sk_lookup, remote_port): + case offsetof(struct bpf_sk_lookup, remote_port) ... + offsetof(struct bpf_sk_lookup, local_ip4) - 1: case bpf_ctx_range(struct bpf_sk_lookup, local_port): case bpf_ctx_range(struct bpf_sk_lookup, ingress_ifindex): bpf_ctx_record_field_size(info, sizeof(__u32)); |