------------[ cut here ]------------
mptcp_pm_is_kernel(msk)
WARNING: net/mptcp/pm.c:446 at mptcp_pm_alloc_anno_list+0x8bc/0x980 net/mptcp/pm.c:446, CPU#1: kworker/1:9/9281
Modules linked in:
CPU: 1 UID: 0 PID: 9281 Comm: kworker/1:9 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events mptcp_worker
RIP: 0010:mptcp_pm_alloc_anno_list+0x8bc/0x980 net/mptcp/pm.c:446
Code: a9 35 f6 e9 bf fd ff ff e8 81 a9 35 f6 90 0f 0b 90 e9 de f7 ff ff e8 73 a9 35 f6 90 0f 0b 90 e9 34 f8 ff ff e8 65 a9 35 f6 90 <0f> 0b 90 31 c0 e9 76 ff ff ff 48 c7 c1 00 26 30 90 80 e1 07 80 c1
RSP: 0018:ffffc900035af3a0 EFLAGS: 00010293
RAX: ffffffff8b905acb RBX: 0000000000000000 RCX: ffff888026c88000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888028b0ec50 R08: 0000000000020003 R09: 00000000aa1414ac
R10: 00000000aa1414ac R11: 0000000000000000 R12: ffff888028b0e200
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff888098841300
FS:  0000000000000000(0000) GS:ffff8881253aa000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34a09ff8 CR3: 000000009716c000 CR4: 00000000003526f0
DR0: 0000000000000008 DR1: 0000000000000002 DR2: 0000000000000404
DR3: ffffffffefffff14 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 mptcp_pm_create_subflow_or_signal_addr+0x1363/0x1850 net/mptcp/pm_kernel.c:373
 mptcp_pm_nl_subflow_established net/mptcp/pm_kernel.c:443 [inline]
 __mptcp_pm_kernel_worker+0x194e/0x2050 net/mptcp/pm_kernel.c:1573
 mptcp_pm_worker+0x1bb/0x300 net/mptcp/pm.c:1098
 mptcp_worker+0xd3/0x1430 net/mptcp/protocol.c:2998
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3397
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3478
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>