watchdog: BUG: soft lockup - CPU#0 stuck for 143s! [syz.4.668:7902] Modules linked in: irq event stamp: 17531491 hardirqs last enabled at (17531490): [] irqentry_exit+0x74/0x90 kernel/entry/common.c:310 hardirqs last disabled at (17531491): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1050 softirqs last enabled at (15240596): [] __do_softirq kernel/softirq.c:613 [inline] softirqs last enabled at (15240596): [] invoke_softirq kernel/softirq.c:453 [inline] softirqs last enabled at (15240596): [] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 softirqs last disabled at (15240599): [] __do_softirq kernel/softirq.c:613 [inline] softirqs last disabled at (15240599): [] invoke_softirq kernel/softirq.c:453 [inline] softirqs last disabled at (15240599): [] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 CPU: 0 UID: 0 PID: 7902 Comm: syz.4.668 Not tainted 6.15.0-syzkaller-gcd7312a78f36 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:rcu_read_unlock_special+0x87/0x4c0 kernel/rcu/tree_plugin.h:694 Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 c2 e2 f4 10 41 f7 c6 00 00 f0 00 74 49 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b RSP: 0000:ffffc900000073a0 EFLAGS: 00000206 RAX: 6150de5f24787500 RBX: 1ffff92000000e7c RCX: 6150de5f24787500 RDX: 0000000000000002 RSI: ffffffff8d97cf77 RDI: ffffffff8be28800 RBP: ffffc90000007498 R08: ffffffff8fa101f7 R09: 1ffffffff1f4203e R10: dffffc0000000000 R11: fffffbfff1f4203f R12: ffffffff8e144400 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 FS: 00007fdcfd7f66c0(0000) GS:ffff888125c54000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2245f7e2d8 CR3: 0000000076b6a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __rcu_read_unlock+0x84/0xe0 kernel/rcu/tree_plugin.h:438 rcu_read_unlock include/linux/rcupdate.h:873 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19ae/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_node_noprof+0x1bb/0x3c0 mm/slub.c:4249 kmalloc_reserve+0xbd/0x290 net/core/skbuff.c:579 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1336 [inline] ndisc_alloc_skb+0x9f/0x480 net/ipv6/ndisc.c:423 ndisc_send_rs+0x2b5/0x630 net/ipv6/ndisc.c:707 addrconf_rs_timer+0x369/0x670 net/ipv6/addrconf.c:4041 call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403 handle_softirqs+0x286/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0xa3/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:738 RIP: 0010:preempt_schedule_irq+0xb0/0x150 kernel/sched/core.c:7108 Code: 24 20 f6 44 24 21 02 74 0c 90 0f 0b 48 f7 03 08 00 00 00 74 64 bf 01 00 00 00 e8 4b ab 29 f6 e8 26 c3 60 f6 fb bf 01 00 00 00 1b ab ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24 RSP: 0000:ffffc90005367dc0 EFLAGS: 00000282 RAX: 6150de5f24787500 RBX: 0000000000000000 RCX: 6150de5f24787500 RDX: 0000000000000000 RSI: ffffffff8d97cf77 RDI: 0000000000000001 RBP: ffffc90005367e70 R08: ffffffff8fa101f7 R09: 1ffffffff1f4203e R10: dffffc0000000000 R11: fffffbfff1f4203f R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000a6cfb8 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:exit_to_user_mode_loop kernel/entry/common.c:-1 [inline] RIP: 0010:exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] RIP: 0010:irqentry_exit_to_user_mode+0x51/0x120 kernel/entry/common.c:184 Code: 07 85 c0 0f 85 c3 00 00 00 e8 5b f9 44 f6 65 4c 8b 34 25 08 c0 9c 92 49 8b 3e f7 c7 1e 30 02 00 74 53 49 89 ff e8 4f f8 44 f6 <4c> 89 f8 a8 18 74 08 e8 23 10 01 00 4c 89 f8 a9 00 10 00 00 74 0b RSP: 0000:ffffc90005367f38 EFLAGS: 00000286 RAX: 6150de5f24787500 RBX: ffffc90005367f58 RCX: 6150de5f24787500 RDX: 0000000000000000 RSI: ffffffff8d97cf77 RDI: ffffffff8be28800 RBP: 0000000000000000 R08: ffffffff8fa101f7 R09: 1ffffffff1f4203e R10: dffffc0000000000 R11: fffffbfff1f4203f R12: 0000000000000000 R13: 0000000000000000 R14: ffff888026fd3c00 R15: 000000000000000a asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0033:0x7fdcff85eb2b Code: 45 0c 85 c0 75 38 b9 40 42 0f 00 ba 81 00 00 00 4c 89 e6 41 c7 04 24 01 00 00 00 bf ca 00 00 00 31 c0 45 31 ed e8 e5 fd 12 00 8c 0f 1f 00 8b bd 98 00 00 00 31 d2 e8 a3 55 ff ff eb b9 48 8d RSP: 002b:00007fdcfd7f60f0 EFLAGS: 00000217 RAX: 0000000000000000 RBX: 00007fdcffbb5fa8 RCX: 00007fdcff98e929 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fdcffbb5fac RBP: 00007fdcffbb5fa0 R08: 7fffffffffffffff R09: 0000000000000000 R10: 0000000000000007 R11: 0000000000000246 R12: 00007fdcffbb5fac R13: 0000000000000000 R14: 00007ffffbad80b0 R15: 00007ffffbad8198 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 7914 Comm: kworker/u8:9 Not tainted 6.15.0-syzkaller-gcd7312a78f36 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x18/0x70 kernel/kcov.c:217 Code: cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 c0 9c 92 65 8b 15 c8 5e dc 10 <81> e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 3c 16 00 00 RSP: 0018:ffffc90005237698 EFLAGS: 00000202 RAX: ffffffff81b4e7e0 RBX: ffff8880b873cb40 RCX: ffff888026a41e00 RDX: 0000000000000001 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90005237800 R08: ffffffff8fa101f7 R09: 1ffffffff1f4203e R10: dffffc0000000000 R11: fffffbfff1f4203f R12: 1ffff110170c86b5 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b86435a8 FS: 0000000000000000(0000) GS:ffff888125d54000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd28746f19 CR3: 000000000df38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: csd_lock_wait kernel/smp.c:340 [inline] smp_call_function_many_cond+0xf80/0x12d0 kernel/smp.c:885 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2660 [inline] smp_text_poke_batch_finish+0x5e0/0x1100 arch/x86/kernel/alternative.c:2870 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_disable_cpuslocked+0xc5/0x1b0 kernel/jump_label.c:240 static_key_disable+0x1a/0x20 kernel/jump_label.c:248 toggle_allocation_gate+0x1a1/0x240 mm/kfence/core.c:855 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245