From: Sechang Lim [ Upstream commit 990348e5bb457697c2f1f7f7b65154a3334d9d2b ] 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: 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 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 Fixes: d44874910a26 ("bpf: Add BPF_SOCK_OPS_STATE_CB") Signed-off-by: Sechang Lim Reviewed-by: Jiayuan Chen Reviewed-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260611092923.1895982-1-rhkrqnwk98@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin [ Moved inet_csk_prepare_for_destroy_sock() to inet_connection_sock.c due to header dependency, Added a guard arount the call to tcp_clear_sock_ops_cb_flags to avoid calling it for DDCP sockets.] Signed-off-by: Miguel Gazquez (Schneider Electric) --- include/net/inet_connection_sock.h | 8 +------- include/net/tcp.h | 9 +++++++++ net/ipv4/inet_connection_sock.c | 9 +++++++++ 3 files changed, 19 insertions(+), 7 deletions(-) diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h index 3eb715f66cbf..cf391f72c270 100644 --- a/include/net/inet_connection_sock.h +++ b/include/net/inet_connection_sock.h @@ -296,14 +296,8 @@ reqsk_timeout(struct request_sock *req, unsigned long max_timeout) return (unsigned long)min_t(u64, timeout, max_timeout); } -static inline void inet_csk_prepare_for_destroy_sock(struct sock *sk) -{ - /* The below has to be done to allow calling inet_csk_destroy_sock */ - sock_set_flag(sk, SOCK_DEAD); - this_cpu_inc(*sk->sk_prot->orphan_count); -} - void inet_csk_destroy_sock(struct sock *sk); +void inet_csk_prepare_for_destroy_sock(struct sock *sk); void inet_csk_prepare_forced_close(struct sock *sk); /* diff --git a/include/net/tcp.h b/include/net/tcp.h index 23d830a7a6c8..b07429da6bae 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -2513,6 +2513,11 @@ 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) { @@ -2530,6 +2535,10 @@ 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) diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 208f8b173a05..530d495ff7d2 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -1252,6 +1252,15 @@ void inet_csk_destroy_sock(struct sock *sk) } EXPORT_SYMBOL(inet_csk_destroy_sock); +void inet_csk_prepare_for_destroy_sock(struct sock *sk) +{ + /* The below has to be done to allow calling inet_csk_destroy_sock */ + if (sk->sk_protocol == IPPROTO_TCP) + tcp_clear_sock_ops_cb_flags(sk); + sock_set_flag(sk, SOCK_DEAD); + this_cpu_inc(*sk->sk_prot->orphan_count); +} + /* This function allows to force a closure of a socket after the call to * tcp/dccp_create_openreq_child(). */ --- base-commit: a4a971135a2ff64382ae4235b3ae60503bb1036a change-id: 20260908-cve-2026-74268-6-6-91de7f0721cd Best regards, -- Miguel Gazquez (Schneider Electric)