syzbot

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BUG: KCSAN: data-race in nci_add_new_protocol / nci_start_poll

write to 0xffff88816bd7a1b0 of 4 bytes by task 402 on cpu 0:
 nci_start_poll+0xb23/0xca0 net/nfc/nci/core.c:858
 nfc_start_poll+0x109/0x160 net/nfc/core.c:225
 nfc_genl_start_poll+0x12b/0x1b0 net/nfc/netlink.c:828
 genl_family_rcv_msg_doit net/netlink/genetlink.c:968 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:1048 [inline]
 genl_rcv_msg+0x65b/0x700 net/netlink/genetlink.c:1065
 netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2546
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1076
 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
 netlink_unicast+0x56f/0x640 net/netlink/af_netlink.c:1365
 netlink_sendmsg+0x665/0x770 net/netlink/af_netlink.c:1913
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg net/socket.c:747 [inline]
 ____sys_sendmsg+0x375/0x4c0 net/socket.c:2503
 ___sys_sendmsg net/socket.c:2557 [inline]
 __sys_sendmsg+0x1e3/0x270 net/socket.c:2586
 __do_sys_sendmsg net/socket.c:2595 [inline]
 __se_sys_sendmsg net/socket.c:2593 [inline]
 __x64_sys_sendmsg+0x46/0x50 net/socket.c:2593
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88816bd7a1b0 of 4 bytes by task 17883 on cpu 1:
 nci_add_new_protocol+0x100/0x370 net/nfc/nci/ntf.c:232
 nci_add_new_target net/nfc/nci/ntf.c:312 [inline]
 nci_rf_discover_ntf_packet net/nfc/nci/ntf.c:384 [inline]
 nci_ntf_packet+0xe90/0x14a0 net/nfc/nci/ntf.c:798
 nci_rx_work+0x108/0x200 net/nfc/nci/core.c:1517
 process_one_work+0x3e6/0x750 kernel/workqueue.c:2408
 worker_thread+0x5f2/0xa10 kernel/workqueue.c:2555
 kthread+0x1d7/0x210 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

value changed: 0x00000000 -> 0xffffffff

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17883 Comm: kworker/u4:0 Not tainted 6.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Workqueue: nfc2_nci_rx_wq nci_rx_work
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nci: nci_add_new_protocol: the target found does not have the desired protocol
nci: nci_add_new_protocol: the target found does not have the desired protocol