diff options
author | Jason Baron <jbaron@akamai.com> | 2020-08-10 20:38:39 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2020-08-10 22:12:35 +0300 |
commit | f19008e676366c44e9241af57f331b6c6edf9552 (patch) | |
tree | 692c3ded574632b92eba694b3b08f7cf503f53b1 /net/ipv4/tcp.c | |
parent | 56e287b3daa20a95e0756e016362f2e96158e1a3 (diff) | |
download | linux-f19008e676366c44e9241af57f331b6c6edf9552.tar.xz |
tcp: correct read of TFO keys on big endian systems
When TFO keys are read back on big endian systems either via the global
sysctl interface or via getsockopt() using TCP_FASTOPEN_KEY, the values
don't match what was written.
For example, on s390x:
# echo "1-2-3-4" > /proc/sys/net/ipv4/tcp_fastopen_key
# cat /proc/sys/net/ipv4/tcp_fastopen_key
02000000-01000000-04000000-03000000
Instead of:
# cat /proc/sys/net/ipv4/tcp_fastopen_key
00000001-00000002-00000003-00000004
Fix this by converting to the correct endianness on read. This was
reported by Colin Ian King when running the 'tcp_fastopen_backup_key' net
selftest on s390x, which depends on the read value matching what was
written. I've confirmed that the test now passes on big and little endian
systems.
Signed-off-by: Jason Baron <jbaron@akamai.com>
Fixes: 438ac88009bc ("net: fastopen: robustness and endianness fixes for SipHash")
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Eric Dumazet <edumazet@google.com>
Reported-and-tested-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp.c')
-rw-r--r-- | net/ipv4/tcp.c | 16 |
1 files changed, 4 insertions, 12 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index c06d2bfd2ec4..31f3b858db81 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3685,22 +3685,14 @@ static int do_tcp_getsockopt(struct sock *sk, int level, return 0; case TCP_FASTOPEN_KEY: { - __u8 key[TCP_FASTOPEN_KEY_BUF_LENGTH]; - struct tcp_fastopen_context *ctx; - unsigned int key_len = 0; + u64 key[TCP_FASTOPEN_KEY_BUF_LENGTH / sizeof(u64)]; + unsigned int key_len; if (get_user(len, optlen)) return -EFAULT; - rcu_read_lock(); - ctx = rcu_dereference(icsk->icsk_accept_queue.fastopenq.ctx); - if (ctx) { - key_len = tcp_fastopen_context_len(ctx) * - TCP_FASTOPEN_KEY_LENGTH; - memcpy(&key[0], &ctx->key[0], key_len); - } - rcu_read_unlock(); - + key_len = tcp_fastopen_get_cipher(net, icsk, key) * + TCP_FASTOPEN_KEY_LENGTH; len = min_t(unsigned int, len, key_len); if (put_user(len, optlen)) return -EFAULT; |