kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 watchdog: BUG: soft lockup - CPU#0 stuck for 222s! [kworker/u4:6:438] Modules linked in: CPU: 0 PID: 438 Comm: kworker/u4:6 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_many_cond+0x8e3/0xa10 kernel/smp.c:969 Code: 84 c0 0f 85 9d 00 00 00 41 8b 1f 89 de 83 e6 01 31 ff e8 30 50 0a 00 83 e3 01 48 8b 5c 24 10 75 07 e8 71 4c 0a 00 eb 42 f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 10 41 f7 RSP: 0018:ffffc90007757860 EFLAGS: 00000293 RAX: ffffffff815f7d95 RBX: ffff8881f7038e80 RCX: ffff888113d693c0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90007757978 R08: ffff8881f7038e97 R09: 1ffff1103ee071d2 R10: dffffc0000000000 R11: ffffed103ee071d3 R12: 1ffff1103ee071d0 R13: 1ffff1103ee2784d R14: 0000000000000001 R15: ffff8881f713c268 FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd48055bff8 CR3: 000000000660f000 CR4: 00000000003506b0 Call Trace: on_each_cpu_cond_mask+0x43/0x80 kernel/smp.c:1134 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1442 [inline] text_poke_bp_batch+0x1d4/0x600 arch/x86/kernel/alternative.c:1642 text_poke_flush arch/x86/kernel/alternative.c:1833 [inline] text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:1840 arch_jump_label_transform_apply+0x15/0x30 arch/x86/kernel/jump_label.c:146 __jump_label_update+0x37c/0x3a0 kernel/jump_label.c:459 jump_label_update+0x39b/0x450 kernel/jump_label.c:830 static_key_enable_cpuslocked+0x126/0x240 kernel/jump_label.c:177 static_key_enable+0x1a/0x30 kernel/jump_label.c:190 toggle_allocation_gate+0xba/0x440 mm/kfence/core.c:783 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 11117 Comm: syz.9.3011 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:write_comp_data kernel/kcov.c:227 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x36/0x90 kernel/kcov.c:293 Code: e0 9f 98 7e 65 8b 15 e1 9f 98 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 5b 83 b9 5c 0b 00 00 00 74 52 8b 91 38 0b 00 00 <83> fa 03 75 47 48 8b 91 40 0b 00 00 44 8b 89 3c 0b 00 00 49 c1 e1 RSP: 0018:ffffc90000a87a00 EFLAGS: 00000046 RAX: ffffffff82c46c60 RBX: 0000000000000000 RCX: ffff88811147bb40 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000a87a00 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000150f2c R12: 1ffff11020b7bae4 R13: ffff888105bdd724 R14: ffff888105bdd700 R15: dffffc0000000000 FS: 00007f98923cd6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd47c15c000 CR3: 0000000155562000 CR4: 00000000003506a0 Call Trace: __vga_put drivers/gpu/vga/vgaarb.c:391 [inline] vga_put drivers/gpu/vga/vgaarb.c:562 [inline] vga_arb_release+0x2c0/0x930 drivers/gpu/vga/vgaarb.c:1350 __fput+0x20b/0x8b0 fs/file_table.c:311 ____fput+0x15/0x20 fs/file_table.c:339 task_work_run+0x127/0x190 kernel/task_work.c:188 get_signal+0x13fb/0x1480 kernel/signal.c:2679 arch_do_signal_or_restart+0xdf/0x11c0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0xa7/0xe0 kernel/entry/common.c:178 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f9893972dd9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f98923cd028 EFLAGS: 00000246 ORIG_RAX: 000000000000010f RAX: 0000000000000001 RBX: 00007f9893bebfa0 RCX: 00007f9893972dd9 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00002000000000c0 RBP: 00007f9893a08d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9893bec038 R14: 00007f9893bebfa0 R15: 00007ffc39eb9758