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BUG: KCSAN: data-race in mptcp_rcv_space_init / tcp_mstamp_refresh

write to 0xffff8881194f6d28 of 8 bytes by interrupt on cpu 0:
 tcp_mstamp_refresh+0x51/0x70 net/ipv4/tcp_output.c:60
 tcp_rcv_established+0x6a/0xf50 net/ipv4/tcp_input.c:6044
 tcp_v6_do_rcv+0x3be/0xac0 net/ipv6/tcp_ipv6.c:1649
 tcp_v6_rcv+0x1a54/0x1d60 net/ipv6/tcp_ipv6.c:1918
 ip6_protocol_deliver_rcu+0xa17/0x10d0 net/ipv6/ip6_input.c:438
 ip6_input_finish+0xf0/0x1d0 net/ipv6/ip6_input.c:489
 NF_HOOK include/linux/netfilter.h:318 [inline]
 ip6_input+0x5e/0x140 net/ipv6/ip6_input.c:500
 dst_input include/net/dst.h:471 [inline]
 ip6_rcv_finish+0x1fa/0x340 net/ipv6/ip6_input.c:79
 NF_HOOK include/linux/netfilter.h:318 [inline]
 ipv6_rcv+0x72/0x150 net/ipv6/ip6_input.c:311
 __netif_receive_skb_one_core net/core/dev.c:5979 [inline]
 __netif_receive_skb+0x9e/0x270 net/core/dev.c:6092
 process_backlog+0x229/0x420 net/core/dev.c:6444
 __napi_poll+0x63/0x310 net/core/dev.c:7497
 napi_poll net/core/dev.c:7560 [inline]
 net_rx_action+0x391/0x830 net/core/dev.c:7687
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 do_softirq+0x5d/0x90 kernel/softirq.c:480
 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:407
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:910 [inline]
 __dev_queue_xmit+0x1200/0x2000 net/core/dev.c:4740
 dev_queue_xmit include/linux/netdevice.h:3358 [inline]
 neigh_hh_output include/net/neighbour.h:531 [inline]
 neigh_output include/net/neighbour.h:545 [inline]
 ip6_finish_output2+0xa3c/0xd30 net/ipv6/ip6_output.c:141
 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline]
 ip6_finish_output+0x3a4/0x540 net/ipv6/ip6_output.c:226
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip6_output+0xfd/0x240 net/ipv6/ip6_output.c:248
 dst_output include/net/dst.h:461 [inline]
 NF_HOOK include/linux/netfilter.h:318 [inline]
 ip6_xmit+0x894/0xc00 net/ipv6/ip6_output.c:367
 inet6_csk_xmit+0x1d1/0x210 net/ipv6/inet6_connection_sock.c:120
 __tcp_transmit_skb+0x1312/0x1a60 net/ipv4/tcp_output.c:1479
 tcp_transmit_skb net/ipv4/tcp_output.c:1497 [inline]
 tcp_write_xmit+0x1210/0x2fd0 net/ipv4/tcp_output.c:2833
 __tcp_push_pending_frames+0x6d/0x1b0 net/ipv4/tcp_output.c:3016
 tcp_send_fin+0x533/0x6b0 net/ipv4/tcp_output.c:3632
 __tcp_close+0x607/0x10c0 net/ipv4/tcp.c:3183
 tcp_close+0x28/0xd0 net/ipv4/tcp.c:3274
 inet_release+0xce/0xf0 net/ipv4/af_inet.c:435
 inet6_release+0x3e/0x60 net/ipv6/af_inet6.c:487
 __sock_release net/socket.c:649 [inline]
 sock_release+0x4b/0xe0 net/socket.c:677
 rds_tcp_accept_one+0x4b7/0x5d0 net/rds/tcp_listen.c:214
 rds_tcp_accept_worker+0x25/0x70 net/rds/tcp.c:529
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3319
 worker_thread+0x582/0x770 kernel/workqueue.c:3400
 kthread+0x486/0x510 kernel/kthread.c:463
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff8881194f6d28 of 8 bytes by task 13302 on cpu 1:
 mptcp_rcv_space_init+0x9a/0x130 net/mptcp/protocol.c:3331
 __mptcp_sync_state+0x2fa/0x430 net/mptcp/subflow.c:466
 mptcp_release_cb+0x5c0/0x670 net/mptcp/protocol.c:3445
 release_sock+0x13b/0x150 net/core/sock.c:3751
 inet_wait_for_connect net/ipv4/af_inet.c:609 [inline]
 __inet_stream_connect+0x56a/0x7e0 net/ipv4/af_inet.c:703
 inet_stream_connect+0x44/0x70 net/ipv4/af_inet.c:748
 __sys_connect_file net/socket.c:2086 [inline]
 __sys_connect+0x1f2/0x2b0 net/socket.c:2105
 __do_sys_connect net/socket.c:2111 [inline]
 __se_sys_connect net/socket.c:2108 [inline]
 __x64_sys_connect+0x3f/0x50 net/socket.c:2108
 x64_sys_call+0x2c08/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:43
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x000000000f93bbfe -> 0x000000000f93bcca

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 13302 Comm: syz.1.3470 Not tainted 6.16.0-syzkaller-12016-gbec077162bd0 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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