------------[ cut here ]------------
mptcp_pm_is_kernel(msk)
WARNING: net/mptcp/pm.c:446 at mptcp_pm_alloc_anno_list+0x408/0x4d0 net/mptcp/pm.c:446, CPU#0: kworker/0:4/5757
Modules linked in:
CPU: 0 UID: 0 PID: 5757 Comm: kworker/0:4 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events mptcp_worker
RIP: 0010:mptcp_pm_alloc_anno_list+0x408/0x4d0 net/mptcp/pm.c:446
Code: 8d 7b 30 49 c7 c0 40 ab 62 9b 48 c7 c1 40 d1 28 8d 31 d2 48 c7 c6 30 be 75 8b e8 e3 3a 7e f6 e9 c6 fc ff ff e8 49 e3 92 f6 90 <0f> 0b 90 31 db e9 09 fd ff ff 48 c7 c7 c4 7d d7 90 e8 02 d3 ff f6
RSP: 0018:ffffc90003b2f818 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888036e02800 RCX: ffffffff8b75a94f
RDX: ffff8880348a9f00 RSI: ffffffff8b75ac97 RDI: ffff8880348a9f00
RBP: ffff88803de5c980 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88803de5c980 R15: ffff8880abf22180
FS:  0000000000000000(0000) GS:ffff888124387000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31a1cff8 CR3: 0000000095488000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 mptcp_pm_create_subflow_or_signal_addr+0xa7a/0x18a0 net/mptcp/pm_kernel.c:373
 mptcp_pm_nl_subflow_established net/mptcp/pm_kernel.c:443 [inline]
 __mptcp_pm_kernel_worker+0xe5/0x1f0 net/mptcp/pm_kernel.c:1573
 mptcp_pm_worker+0x12b/0x320 net/mptcp/pm.c:1098
 mptcp_worker+0x15d/0x1420 net/mptcp/protocol.c:2998
 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314
 process_scheduled_works kernel/workqueue.c:3397 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>