watchdog: BUG: soft lockup - CPU#1 stuck for 143s! [syz.8.3987:20473] Modules linked in: irq event stamp: 14354375 hardirqs last enabled at (14354374): [] irqentry_exit+0x59e/0x620 kernel/entry/common.c:242 hardirqs last disabled at (14354375): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1056 softirqs last enabled at (14252664): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last enabled at (14252664): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last enabled at (14252664): [] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 softirqs last disabled at (14252667): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last disabled at (14252667): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last disabled at (14252667): [] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 CPU: 1 UID: 0 PID: 20473 Comm: syz.8.3987 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:perf_trace_buf_alloc+0x1c7/0x280 kernel/trace/trace_event_perf.c:421 Code: 4c 89 ff e8 ab 35 60 00 4d 03 37 48 63 c3 4a 8d 3c 30 48 83 c7 f8 ba 08 00 00 00 31 f6 e8 61 38 60 00 4c 89 f0 48 83 c4 08 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 15 12 f6 ff 48 8d RSP: 0018:ffffc90000a08450 EFLAGS: 00000286 RAX: ffffe8ffffdb2000 RBX: ffffffff8e62c3e8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffe8ffffdb202c RBP: 0000000000000001 R08: 0000000000000004 R09: 0000000000000004 R10: ffffe8ffffdb2024 R11: fffff91ffffb6406 R12: ffffffff8e1a9798 R13: dffffc0000000000 R14: ffffe8ffffdb2000 R15: ffffffff8e1a9798 FS: 00007f29e93ee6c0(0000) GS:ffff888125566000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3d2de00020 CR3: 0000000028cb0000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: do_perf_trace_lock include/trace/events/lock.h:50 [inline] perf_trace_lock+0x1a0/0x410 include/trace/events/lock.h:50 __do_trace_lock_release include/trace/events/lock.h:69 [inline] trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x392/0x3d0 kernel/locking/lockdep.c:5879 rcu_lock_release include/linux/rcupdate.h:322 [inline] rcu_read_unlock include/linux/rcupdate.h:881 [inline] class_rcu_destructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0x1aaa/0x23c0 arch/x86/kernel/unwind_orc.c:695 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 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4501 [inline] slab_alloc_node mm/slub.c:4830 [inline] kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4882 __alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702 alloc_skb include/linux/skbuff.h:1383 [inline] ndisc_alloc_skb+0x9f/0x480 net/ipv6/ndisc.c:420 ndisc_send_rs+0x2b5/0x630 net/ipv6/ndisc.c:706 addrconf_rs_timer+0x395/0x6d0 net/ipv6/addrconf.c:4042 call_timer_fn+0x192/0x640 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/0x870 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:__sanitizer_cov_trace_pc+0x45/0x70 kernel/kcov.c:222 Code: ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 54 16 00 00 00 74 2c 8b 91 30 16 00 00 83 fa 02 75 21 48 8b 91 38 16 00 00 48 8b 32 <48> 8d 7e 01 8b 89 34 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 RSP: 0018:ffffc9000438f2e8 EFLAGS: 00000246 RAX: ffffffff8216c477 RBX: ffff888034e60c40 RCX: ffff88801d760000 RDX: ffffc9001e7f4000 RSI: 000000000007ffff RDI: 0000000000000000 RBP: ffffc9000438f5f0 R08: ffffffff901172b7 R09: 1ffffffff2022e56 R10: dffffc0000000000 R11: fffffbfff2022e57 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffffc9000438f540 R15: 0000000000000000 add_mm_rss_vec+0xf7/0x320 mm/memory.c:504 zap_pte_range mm/memory.c:1951 [inline] zap_pmd_range mm/memory.c:2021 [inline] zap_pud_range mm/memory.c:2049 [inline] zap_p4d_range mm/memory.c:2070 [inline] unmap_page_range+0x35d4/0x48f0 mm/memory.c:2091 unmap_single_vma mm/memory.c:2133 [inline] unmap_vmas+0x48f/0x6a0 mm/memory.c:2171 exit_mmap+0x280/0xa10 mm/mmap.c:1302 __mmput+0x118/0x430 kernel/fork.c:1174 copy_process+0x29a7/0x3cf0 kernel/fork.c:2503 kernel_clone+0x248/0x8e0 kernel/fork.c:2654 __do_sys_clone kernel/fork.c:2795 [inline] __se_sys_clone kernel/fork.c:2779 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2779 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f29eb19c629 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:00007f29e93edfd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f29eb415fa0 RCX: 00007f29eb19c629 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f29eb232b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f29eb416038 R14: 00007f29eb415fa0 R15: 00007ffc3f61f228 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 20631 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xce5/0x12c0 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 24 e3 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 cf de 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 b3 de RSP: 0018:ffffc90005337680 EFLAGS: 00000293 RAX: ffffffff81b9addd RBX: 1ffff110170e812d RCX: ffff88803674bc80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900053377c0 R08: ffffffff901172b7 R09: 1ffffffff2022e56 R10: dffffc0000000000 R11: fffffbfff2022e57 R12: ffff8880b8740968 R13: dffffc0000000000 R14: ffff8880b863bf80 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125466000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055cc67ff8a38 CR3: 000000000e54c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 __flush_tlb_multi arch/x86/include/asm/paravirt.h:57 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline] flush_tlb_mm_range+0x5c3/0x10c0 arch/x86/mm/tlb.c:1472 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:505 [inline] tlb_flush_mmu+0x1af/0xa30 mm/mmu_gather.c:404 tlb_finish_mmu+0xf9/0x230 mm/mmu_gather.c:530 free_ldt_pgtables+0x19d/0x350 arch/x86/kernel/ldt.c:411 arch_exit_mmap arch/x86/include/asm/mmu_context.h:232 [inline] exit_mmap+0x1af/0xa10 mm/mmap.c:1287 __mmput+0x118/0x430 kernel/fork.c:1174 exit_mm+0x168/0x220 kernel/exit.c:581 do_exit+0x62e/0x2320 kernel/exit.c:959 do_group_exit+0x21b/0x2d0 kernel/exit.c:1112 __do_sys_exit_group kernel/exit.c:1123 [inline] __se_sys_exit_group kernel/exit.c:1121 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fefa1cf16c5 Code: Unable to access opcode bytes at 0x7fefa1cf169b. RSP: 002b:00007ffc4fac30a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000055cc680318f0 RCX: 00007fefa1cf16c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000055cc67fef910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc4fac30f0 R14: 0000000000000000 R15: 0000000000000000