[moderation] [net?] [nfc?] KCSAN: data-race in nci_dev_up / nci_req_complete (5)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: aacb0a6d604a Merge tag 'pmdomain-v6.19-rc3' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14f0b69a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b319ff1b6a2797ca
dashboard link: https://syzkaller.appspot.com/bug?extid=43e35be410f8b1d6a72d
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
CC: [da...@davemloft.net edum...@google.com ho...@kernel.org kr...@kernel.org ku...@kernel.org linux-...@vger.kernel.org net...@vger.kernel.org pab...@redhat.com]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/fb50ebef3bc0/disk-aacb0a6d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3c357a711af6/vmlinux-aacb0a6d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/926530a78dea/bzImage-aacb0a6d.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+43e35b...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in nci_dev_up / nci_req_complete

write to 0xffff88811bfb69a0 of 4 bytes by task 6091 on cpu 1:
__nci_request net/nfc/nci/core.c:136 [inline]
nci_open_device net/nfc/nci/core.c:503 [inline]
nci_dev_up+0x272/0x8f0 net/nfc/nci/core.c:632
nfc_dev_up+0x103/0x1b0 net/nfc/core.c:118
nfc_genl_dev_up+0x53/0x90 net/nfc/netlink.c:775
genl_family_rcv_msg_doit+0x143/0x1b0 net/netlink/genetlink.c:1115
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0x422/0x460 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x123/0x220 net/netlink/af_netlink.c:2550
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x5c0/0x690 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x58b/0x6b0 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x145/0x180 net/socket.c:742
____sys_sendmsg+0x31e/0x4a0 net/socket.c:2592
___sys_sendmsg+0x17b/0x1d0 net/socket.c:2646
__sys_sendmsg net/socket.c:2678 [inline]
__do_sys_sendmsg net/socket.c:2683 [inline]
__se_sys_sendmsg net/socket.c:2681 [inline]
__x64_sys_sendmsg+0xd4/0x160 net/socket.c:2681
x64_sys_call+0x17ba/0x3000 arch/x86/include/generated/asm/syscalls_64.h:47
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xca/0x2b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811bfb69a0 of 4 bytes by task 2331 on cpu 0:
nci_req_complete+0x23/0x90 net/nfc/nci/core.c:80
nci_rsp_packet+0xc6f/0xe30 net/nfc/nci/rsp.c:-1
nci_rx_work+0x16f/0x2c0 net/nfc/nci/core.c:1551
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3340
worker_thread+0x582/0x770 kernel/workqueue.c:3421
kthread+0x489/0x510 kernel/kthread.c:463
ret_from_fork+0x149/0x290 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 2331 Comm: kworker/u8:13 Not tainted syzkaller #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: nfc2_nci_rx_wq nci_rx_work
==================================================================


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