watchdog: BUG: soft lockup - CPU#0 stuck for 120s! [syz.0.1632:11781] Modules linked in: irq event stamp: 17981907 hardirqs last enabled at (17981906): [] irqentry_exit+0x59c/0x620 kernel/entry/common.c:219 hardirqs last disabled at (17981907): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1056 softirqs last enabled at (17927292): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last enabled at (17927292): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last enabled at (17927292): [] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 softirqs last disabled at (17927295): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last disabled at (17927295): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last disabled at (17927295): [] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 CPU: 0 UID: 0 PID: 11781 Comm: syz.0.1632 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:lock_acquire+0x221/0x330 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 f1 f8 fa 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 db 59 54 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 c0 dc fd 09 cc 48 8d 3d 18 7f 52 RSP: 0018:ffffc90000007298 EFLAGS: 00000282 RAX: 27ad4935407f8c00 RBX: 0000000000000000 RCX: 0000000000000101 RDX: 0000000082b5193f RSI: ffffffff8df3d941 RDI: ffffffff8c075280 RBP: ffffffff8175a195 R08: ffffffff8175a195 R09: ffffffff8e557fe0 R10: ffffc90000006f08 R11: ffffffff81af8c70 R12: 0000000000000002 R13: ffffffff8e557fe0 R14: 0000000000000000 R15: 0000000000000246 FS: 00007f2e339956c0(0000) GS:ffff8881256d3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2876200040 CR3: 000000007568e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:302 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] class_rcu_constructor include/linux/rcupdate.h:1166 [inline] unwind_next_frame+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x3d1/0x6e0 mm/slub.c:5780 kmalloc_noprof include/linux/slab.h:958 [inline] kzalloc_noprof include/linux/slab.h:1200 [inline] ref_tracker_alloc+0x161/0x4d0 lib/ref_tracker.c:271 __netdev_tracker_alloc include/linux/netdevice.h:4400 [inline] netdev_hold include/linux/netdevice.h:4429 [inline] dst_init+0xd9/0x480 net/core/dst.c:52 dst_alloc+0x12a/0x170 net/core/dst.c:94 ip6_dst_alloc net/ipv6/route.c:342 [inline] icmp6_dst_alloc+0x75/0x440 net/ipv6/route.c:3333 ndisc_send_skb+0x42d/0x14e0 net/ipv6/ndisc.c:491 addrconf_rs_timer+0x395/0x6d0 net/ipv6/addrconf.c:4037 call_timer_fn+0x192/0x5a0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:rcu_read_unlock_special+0x1d/0x480 kernel/rcu/tree_plugin.h:773 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 48 83 ec 10 65 8b 2d 8b 90 4a 11 f7 c5 00 00 f0 00 74 14 <48> 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 49 89 RSP: 0018:ffffc9000eaeeaa0 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000246 RCX: 0000000000000001 RDX: 0000000000000007 RSI: ffffffff8dccf6b3 RDI: ffffffff8c075280 RBP: ffff8881256d3000 R08: ffffffff8fefab77 R09: 1ffffffff1fdf56e R10: dffffc0000000000 R11: fffffbfff1fdf56f R12: ffffffff8e55db78 R13: dffffc0000000000 R14: ffff8880b863b958 R15: 1ffff110170c772b __rcu_read_unlock+0x83/0xe0 kernel/rcu/tree_plugin.h:438 rcu_read_unlock include/linux/rcupdate.h:870 [inline] class_rcu_destructor include/linux/rcupdate.h:1166 [inline] unwind_next_frame+0x1aaf/0x23c0 arch/x86/kernel/unwind_orc.c:695 __unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:773 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3131 [inline] call_rcu+0xee/0x890 kernel/rcu/tree.c:3251 context_switch kernel/sched/core.c:5263 [inline] __schedule+0x152a/0x51d0 kernel/sched/core.c:6867 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7194 irqentry_exit+0x597/0x620 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:put_cpu_partial+0x1db/0x280 mm/slub.c:3960 Code: 5b 41 5c 41 5d 41 5e 41 5f 5d e9 90 e9 ff ff 90 0f 0b 90 e9 15 ff ff ff e8 f2 a7 78 09 41 f7 c5 00 02 00 00 74 cf fb 4d 85 ff <75> ce 5b 41 5c 41 5d 41 5e 41 5f 5d e9 d4 8b 7b 09 cc e8 ce a7 78 RSP: 0018:ffffc9000eaef388 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff88813fe303c0 RCX: 0000000000000046 RDX: 0000000000000007 RSI: ffffffff8dccf6b3 RDI: ffffffff8c075280 RBP: 0000000000000001 R08: ffffffff8fefab77 R09: 1ffffffff1fdf56e R10: dffffc0000000000 R11: fffffbfff1fdf56f R12: 0000000000000000 R13: 0000000000000246 R14: ffff8880b8640010 R15: 0000000000000000 __slab_free+0x294/0x320 mm/slub.c:5956 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_node_noprof+0x427/0x6f0 mm/slub.c:5315 __alloc_skb+0x1d7/0x390 net/core/skbuff.c:679 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6715 sock_alloc_send_pskb+0x878/0x990 net/core/sock.c:2995 unix_dgram_sendmsg+0x460/0x18e0 net/unix/af_unix.c:2130 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa68/0xad0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 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+0x1bd/0x2a0 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2e32b9bf79 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:00007f2e33995028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f2e32e15fa0 RCX: 00007f2e32b9bf79 RDX: 0000000000000000 RSI: 0000200000001b00 RDI: 0000000000000009 RBP: 00007f2e32c327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2e32e16038 R14: 00007f2e32e15fa0 R15: 00007ffc39e38a68 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8982 Comm: kworker/u8:21 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xce5/0x1270 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 14 fa 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 bf f5 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 a3 f5 RSP: 0018:ffffc9000cd37720 EFLAGS: 00000293 RAX: ffffffff81b87a6d RBX: 1ffff110170c8579 RCX: ffff88802e5d3c80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000cd37860 R08: ffffffff8fefab77 R09: 1ffffffff1fdf56e R10: dffffc0000000000 R11: fffffbfff1fdf56f R12: ffff8880b8642bc8 R13: dffffc0000000000 R14: ffff8880b873bb40 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881257d3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2876615f40 CR3: 000000000e344000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000200000000300 DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2711 [inline] smp_text_poke_batch_finish+0x5f5/0x1160 arch/x86/kernel/alternative.c:2921 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:894 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340 worker_thread+0xda6/0x1360 kernel/workqueue.c:3421 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246