diff options
| author | Jakub Kicinski <kuba@kernel.org> | 2025-09-17 16:01:54 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-09-17 16:01:54 -0700 |
| commit | d7995c2b91a5709a959f689b33655029814149b3 (patch) | |
| tree | 81c0200188f277a08e2c3acc928c69fe3ba95a6f | |
| parent | a72175c985132885573593222a7b088cf49b07ae (diff) | |
| parent | 1fd0362262baff9381615a5b346298abbc165ba3 (diff) | |
Merge branch 'tcp-clear-tcp_sk-sk-fastopen_rsk-in-tcp_disconnect'
Kuniyuki Iwashima says:
====================
tcp: Clear tcp_sk(sk)->fastopen_rsk in tcp_disconnect().
syzbot reported a warning in tcp_retransmit_timer() for TCP Fast
Open socket.
Patch 1 fixes the issue and Patch 2 adds a test for the scenario.
====================
Link: https://patch.msgid.link/20250915175800.118793-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/ipv4/tcp.c | 5 | ||||
| -rw-r--r-- | tools/testing/selftests/net/packetdrill/tcp_fastopen_server_reset-after-disconnect.pkt | 26 |
2 files changed, 31 insertions, 0 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 71a956fbfc55..ad76556800f2 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3327,6 +3327,7 @@ int tcp_disconnect(struct sock *sk, int flags) struct inet_connection_sock *icsk = inet_csk(sk); struct tcp_sock *tp = tcp_sk(sk); int old_state = sk->sk_state; + struct request_sock *req; u32 seq; if (old_state != TCP_CLOSE) @@ -3442,6 +3443,10 @@ int tcp_disconnect(struct sock *sk, int flags) /* Clean up fastopen related fields */ + req = rcu_dereference_protected(tp->fastopen_rsk, + lockdep_sock_is_held(sk)); + if (req) + reqsk_fastopen_remove(sk, req, false); tcp_free_fastopen_req(tp); inet_clear_bit(DEFER_CONNECT, sk); tp->fastopen_client_fail = 0; diff --git a/tools/testing/selftests/net/packetdrill/tcp_fastopen_server_reset-after-disconnect.pkt b/tools/testing/selftests/net/packetdrill/tcp_fastopen_server_reset-after-disconnect.pkt new file mode 100644 index 000000000000..26794e7ddfd5 --- /dev/null +++ b/tools/testing/selftests/net/packetdrill/tcp_fastopen_server_reset-after-disconnect.pkt @@ -0,0 +1,26 @@ +// SPDX-License-Identifier: GPL-2.0 +`./defaults.sh + ./set_sysctls.py /proc/sys/net/ipv4/tcp_fastopen=0x602 /proc/sys/net/ipv4/tcp_timestamps=0` + + 0 socket(..., SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 3 + +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 + +0 bind(3, ..., ...) = 0 + +0 listen(3, 1) = 0 + + +0 < S 0:10(10) win 32792 <mss 1460,nop,nop,sackOK> + +0 > S. 0:0(0) ack 11 win 65535 <mss 1460,nop,nop,sackOK> + +// sk->sk_state is TCP_SYN_RECV + +.1 accept(3, ..., ...) = 4 + +// tcp_disconnect() sets sk->sk_state to TCP_CLOSE + +0 connect(4, AF_UNSPEC, ...) = 0 + +0 > R. 1:1(0) ack 11 win 65535 + +// connect() sets sk->sk_state to TCP_SYN_SENT + +0 fcntl(4, F_SETFL, O_RDWR|O_NONBLOCK) = 0 + +0 connect(4, ..., ...) = -1 EINPROGRESS (Operation is now in progress) + +0 > S 0:0(0) win 65535 <mss 1460,nop,nop,sackOK,nop,wscale 8> + +// tp->fastopen_rsk must be NULL + +1 > S 0:0(0) win 65535 <mss 1460,nop,nop,sackOK,nop,wscale 8> |