diff options
| author | Sechang Lim <rhkrqnwk98@gmail.com> | 2026-06-11 09:29:18 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-06-12 16:18:39 -0700 |
| commit | 990348e5bb457697c2f1f7f7b65154a3334d9d2b (patch) | |
| tree | 91513936806986a8ed15dd7f954a3c43ef3a8f43 /include | |
| parent | e26657fe3b85c068b01f42bb0c602f242d643ba9 (diff) | |
tcp: clear sock_ops cb flags before force-closing a child socket
A child socket inherits the listener's bpf_sock_ops_cb_flags via
sk_clone_lock(). If its setup fails in tcp_v4_syn_recv_sock() /
tcp_v6_syn_recv_sock(), the child is freed through put_and_exit, where
inet_csk_prepare_forced_close() drops the socket lock and tcp_done() runs
without it.
If BPF_SOCK_OPS_STATE_CB_FLAG was inherited, tcp_done() -> tcp_set_state()
calls tcp_call_bpf(), which expects the lock and trips sock_owned_by_me():
WARNING: include/net/sock.h:1799 at tcp_set_state+0x433/0x550
RIP: 0010:tcp_set_state+0x433/0x550 include/net/sock.h:1799
Call Trace:
<IRQ>
tcp_done+0xba/0x250 net/ipv4/tcp.c:5095
tcp_v4_syn_recv_sock+0x850/0xa50 net/ipv4/tcp_ipv4.c:1787
tcp_check_req+0xf30/0x1360 net/ipv4/tcp_minisocks.c:926
tcp_v4_rcv+0x1047/0x1b50 net/ipv4/tcp_ipv4.c:2164
</IRQ>
The child is freed before it is ever established, so it should run no
sock_ops callback. Clear its cb flags in inet_csk_prepare_for_destroy_sock(),
the common point for the IPv4, IPv6 and chtls forced-close paths and for the
MPTCP ->syn_recv_sock() failure path (dispose_child), which reaches tcp_done()
on a child that was never established too.
Suggested-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Fixes: d44874910a26 ("bpf: Add BPF_SOCK_OPS_STATE_CB")
Signed-off-by: Sechang Lim <rhkrqnwk98@gmail.com>
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260611092923.1895982-1-rhkrqnwk98@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/tcp.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index 98848db62894..607298501e12 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -2942,6 +2942,11 @@ static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, return tcp_call_bpf(sk, op, 3, args); } +static inline void tcp_clear_sock_ops_cb_flags(struct sock *sk) +{ + tcp_sk(sk)->bpf_sock_ops_cb_flags = 0; +} + #else static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) { @@ -2959,6 +2964,10 @@ static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, return -EPERM; } +static inline void tcp_clear_sock_ops_cb_flags(struct sock *sk) +{ +} + #endif static inline u32 tcp_timeout_init(struct sock *sk) |