tcp: initialize send sequence numbers before deferring TFO

TCP_FASTOPEN_CONNECT can return from connect() before tcp_connect_init()
when a cached cookie or cookieless Fast Open allows deferring the SYN.
At this point write_seq contains the initial sequence number, while
snd_una and snd_nxt have not been initialized to that sequence number.

Consequently, inet_diag and /proc/net/tcp{,6} report the initial
sequence number as the send queue length despite no SYN or payload being
queued.

Initialize snd_una and snd_nxt to write_seq before marking the
connection as deferred. Both sequence-based queue lengths then remain
zero until the first write starts the connection and runs
tcp_connect_init().

Fixes: 19f6d3f3c842 ("net/tcp-fastopen: Add new API support")
Signed-off-by: Qingfang Deng <qingfang.deng@linux.dev>
Reviewed-by: Eric Dumazet <edumazet@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Link: https://patch.msgid.link/20261102035943.9700-1-qingfang.deng@linux.dev
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

0 files changed, 0 insertions, 0 deletions