================================================================== BUG: KCSAN: data-race in inet_csk_complete_hashdance / sk_clone write to 0xffff88811a49c880 of 8 bytes by interrupt on cpu 1: inet_csk_reqsk_queue_add net/ipv4/inet_connection_sock.c:1413 [inline] inet_csk_complete_hashdance+0x52a/0x740 net/ipv4/inet_connection_sock.c:1455 tcp_check_req+0x1099/0x1150 net/ipv4/tcp_minisocks.c:945 tcp_v4_rcv+0xeda/0x1db0 net/ipv4/tcp_ipv4.c:2242 ip_protocol_deliver_rcu+0x395/0x790 net/ipv4/ip_input.c:207 ip_local_deliver_finish+0x1fc/0x2f0 net/ipv4/ip_input.c:241 NF_HOOK include/linux/netfilter.h:318 [inline] ip_local_deliver+0xe8/0x1e0 net/ipv4/ip_input.c:262 dst_input include/net/dst.h:480 [inline] ip_rcv_finish+0x188/0x1a0 net/ipv4/ip_input.c:453 NF_HOOK include/linux/netfilter.h:318 [inline] ip_rcv+0x62/0x160 net/ipv4/ip_input.c:573 __netif_receive_skb_one_core net/core/dev.c:6164 [inline] __netif_receive_skb net/core/dev.c:6277 [inline] process_backlog+0x341/0x670 net/core/dev.c:6628 __napi_poll+0x61/0x330 net/core/dev.c:7692 napi_poll net/core/dev.c:7755 [inline] net_rx_action+0x452/0x930 net/core/dev.c:7912 handle_softirqs+0xb9/0x2a0 kernel/softirq.c:622 do_softirq+0x45/0x60 kernel/softirq.c:523 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:924 [inline] __dev_queue_xmit+0x136c/0x1f20 net/core/dev.c:4873 dev_queue_xmit include/linux/netdevice.h:3385 [inline] neigh_hh_output include/net/neighbour.h:540 [inline] neigh_output include/net/neighbour.h:554 [inline] ip_finish_output2+0x705/0x8c0 net/ipv4/ip_output.c:237 __ip_finish_output net/ipv4/ip_output.c:-1 [inline] ip_finish_output+0x112/0x290 net/ipv4/ip_output.c:325 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0xbd/0x1c0 net/ipv4/ip_output.c:438 dst_output include/net/dst.h:470 [inline] ip_local_out net/ipv4/ip_output.c:131 [inline] __ip_queue_xmit+0xb68/0xba0 net/ipv4/ip_output.c:534 ip_queue_xmit+0x39/0x50 net/ipv4/ip_output.c:548 __tcp_transmit_skb+0x1af2/0x1f10 net/ipv4/tcp_output.c:1693 __tcp_send_ack+0x288/0x3b0 net/ipv4/tcp_output.c:4503 tcp_send_ack+0x29/0x30 net/ipv4/tcp_output.c:4509 tcp_fin+0x118/0x350 net/ipv4/tcp_input.c:4984 tcp_data_queue+0x8ea/0x3060 net/ipv4/tcp_input.c:5694 tcp_rcv_state_process+0x1bf6/0x21a0 net/ipv4/tcp_input.c:7419 tcp_v4_do_rcv+0x5fe/0xa30 net/ipv4/tcp_ipv4.c:1907 sk_backlog_rcv include/net/sock.h:1185 [inline] __release_sock+0x15e/0x2f0 net/core/sock.c:3213 __tcp_close+0x7c8/0x1130 net/ipv4/tcp.c:3272 tcp_close+0x28/0xd0 net/ipv4/tcp.c:3350 inet_release+0xcd/0xf0 net/ipv4/af_inet.c:443 inet6_release+0x3e/0x60 net/ipv6/af_inet6.c:479 __sock_release net/socket.c:662 [inline] sock_release+0x4b/0xe0 net/socket.c:690 rds_tcp_accept_one+0x334/0x8a0 net/rds/tcp_listen.c:341 rds_tcp_accept_worker+0x1a/0x60 net/rds/tcp.c:530 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0x513/0xa10 kernel/workqueue.c:3359 worker_thread+0x58a/0x780 kernel/workqueue.c:3440 kthread+0x22a/0x280 kernel/kthread.c:436 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 read to 0xffff88811a49c4c4 of 2364 bytes by interrupt on cpu 0: sock_copy net/core/sock.c:2221 [inline] sk_clone+0xce/0xa30 net/core/sock.c:2485 sk_clone_lock include/net/sock.h:1845 [inline] inet_csk_clone_lock+0x28/0x270 net/ipv4/inet_connection_sock.c:1210 tcp_create_openreq_child+0x32/0x12c0 net/ipv4/tcp_minisocks.c:553 tcp_v4_syn_recv_sock+0xbf/0xab0 net/ipv4/tcp_ipv4.c:1725 tcp_v6_syn_recv_sock+0xa8/0xbf0 net/ipv6/tcp_ipv6.c:1371 tcp_check_req+0xddf/0x1150 net/ipv4/tcp_minisocks.c:927 tcp_v4_rcv+0xeda/0x1db0 net/ipv4/tcp_ipv4.c:2242 ip_protocol_deliver_rcu+0x395/0x790 net/ipv4/ip_input.c:207 ip_local_deliver_finish+0x1fc/0x2f0 net/ipv4/ip_input.c:241 NF_HOOK include/linux/netfilter.h:318 [inline] ip_local_deliver+0xe8/0x1e0 net/ipv4/ip_input.c:262 dst_input include/net/dst.h:480 [inline] ip_rcv_finish+0x188/0x1a0 net/ipv4/ip_input.c:453 NF_HOOK include/linux/netfilter.h:318 [inline] ip_rcv+0x62/0x160 net/ipv4/ip_input.c:573 __netif_receive_skb_one_core net/core/dev.c:6164 [inline] __netif_receive_skb net/core/dev.c:6277 [inline] process_backlog+0x341/0x670 net/core/dev.c:6628 __napi_poll+0x61/0x330 net/core/dev.c:7692 napi_poll net/core/dev.c:7755 [inline] net_rx_action+0x452/0x930 net/core/dev.c:7912 handle_softirqs+0xb9/0x2a0 kernel/softirq.c:622 do_softirq+0x45/0x60 kernel/softirq.c:523 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:924 [inline] __dev_queue_xmit+0x136c/0x1f20 net/core/dev.c:4873 dev_queue_xmit include/linux/netdevice.h:3385 [inline] neigh_hh_output include/net/neighbour.h:540 [inline] neigh_output include/net/neighbour.h:554 [inline] ip_finish_output2+0x705/0x8c0 net/ipv4/ip_output.c:237 __ip_finish_output net/ipv4/ip_output.c:-1 [inline] ip_finish_output+0x112/0x290 net/ipv4/ip_output.c:325 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0xbd/0x1c0 net/ipv4/ip_output.c:438 dst_output include/net/dst.h:470 [inline] ip_local_out net/ipv4/ip_output.c:131 [inline] __ip_queue_xmit+0xb68/0xba0 net/ipv4/ip_output.c:534 ip_queue_xmit+0x39/0x50 net/ipv4/ip_output.c:548 __tcp_transmit_skb+0x1af2/0x1f10 net/ipv4/tcp_output.c:1693 __tcp_send_ack+0x288/0x3b0 net/ipv4/tcp_output.c:4503 tcp_send_ack_reflect_ect net/ipv4/tcp_input.c:4038 [inline] tcp_send_challenge_ack+0x267/0x290 net/ipv4/tcp_input.c:4072 tcp_validate_incoming+0xc6d/0x1200 net/ipv4/tcp_input.c:6476 tcp_rcv_established+0x48f/0x12f0 net/ipv4/tcp_input.c:6691 tcp_v4_do_rcv+0x91d/0xa30 net/ipv4/tcp_ipv4.c:1884 sk_backlog_rcv include/net/sock.h:1185 [inline] __release_sock+0x15e/0x2f0 net/core/sock.c:3213 release_sock+0x44/0x150 net/core/sock.c:3795 tcp_sendmsg+0x39/0x50 net/ipv4/tcp.c:1466 inet_sendmsg+0x76/0xd0 net/ipv4/af_inet.c:865 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] sock_sendmsg+0x1db/0x240 net/socket.c:765 kernel_sendmsg+0x44/0x60 net/socket.c:789 rds_tcp_sendmsg net/rds/tcp_send.c:66 [inline] rds_tcp_xmit+0x28b/0x670 net/rds/tcp_send.c:105 rds_send_xmit+0x7b8/0x16f0 net/rds/send.c:425 rds_send_worker+0x44/0x1b0 net/rds/threads.c:200 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0x513/0xa10 kernel/workqueue.c:3359 worker_thread+0x58a/0x780 kernel/workqueue.c:3440 kthread+0x22a/0x280 kernel/kthread.c:436 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 36 Comm: kworker/u8:2 Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: krds_cp_wq#4/0 rds_send_worker 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