[moderation] [smc?] KCSAN: data-race in smc_connect_work / smc_poll

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: da32d155f4a8 Merge tag 'gpio-fixes-for-v6.18-rc5' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10e32a92580000
kernel config: https://syzkaller.appspot.com/x/.config?x=d2e0bc0ae94545f7
dashboard link: https://syzkaller.appspot.com/bug?extid=d117875e286a8282c351
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
CC: [ali...@linux.alibaba.com da...@davemloft.net dus...@linux.alibaba.com edum...@google.com gu...@linux.alibaba.com ho...@kernel.org ku...@kernel.org linux-...@vger.kernel.org linux...@vger.kernel.org linux...@vger.kernel.org mjam...@linux.ibm.com net...@vger.kernel.org pab...@redhat.com sid...@linux.ibm.com ton...@linux.alibaba.com wen...@linux.ibm.com]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/eab8998f7324/disk-da32d155.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/11583c251b43/vmlinux-da32d155.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ee5cf1f37532/bzImage-da32d155.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d11787...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in smc_connect_work / smc_poll

write to 0xffff88811a82089c of 4 bytes by task 3413 on cpu 0:
smc_connect_work+0xef/0x4e0 net/smc/af_smc.c:1606
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3346
worker_thread+0x582/0x770 kernel/workqueue.c:3427
kthread+0x489/0x510 kernel/kthread.c:463
ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff88811a82089c of 4 bytes by task 24721 on cpu 1:
smc_poll+0x188/0x530 net/smc/af_smc.c:2890
sock_poll+0x20d/0x230 net/socket.c:1443
vfs_poll include/linux/poll.h:82 [inline]
select_poll_one fs/select.c:480 [inline]
do_select+0x8f1/0xf40 fs/select.c:536
core_sys_select+0x3dc/0x6e0 fs/select.c:677
do_pselect fs/select.c:759 [inline]
__do_sys_pselect6 fs/select.c:802 [inline]
__se_sys_pselect6+0x216/0x280 fs/select.c:793
__x64_sys_pselect6+0x78/0x90 fs/select.c:793
x64_sys_call+0x28bd/0x3000 arch/x86/include/generated/asm/syscalls_64.h:271
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: 0x00000000 -> 0x0000006f

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 24721 Comm: syz.1.7092 Tainted: G W syzkaller #0 PREEMPT(voluntary)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
==================================================================


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