watchdog: BUG: soft lockup - CPU#0 stuck for 144s! [syz.2.12343:10650] Modules linked in: irq event stamp: 12941377 hardirqs last enabled at (12941376): [] irqentry_exit+0x59e/0x620 kernel/entry/common.c:242 hardirqs last disabled at (12941377): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1056 softirqs last enabled at (12784426): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last enabled at (12784426): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last enabled at (12784426): [] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 softirqs last disabled at (12784429): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last disabled at (12784429): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last disabled at (12784429): [] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 CPU: 0 UID: 0 PID: 10650 Comm: syz.2.12343 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:do_perf_trace_lock include/trace/events/lock.h:-1 [inline] RIP: 0010:perf_trace_lock+0x135/0x410 include/trace/events/lock.h:50 Code: 8d 1c dd 90 d7 1a 8e 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 38 10 8f 00 48 8b 44 24 18 48 03 03 48 89 44 24 18 <4c> 89 74 24 38 49 8d 5e 68 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 RSP: 0018:ffffc90000006a80 EFLAGS: 00000282 RAX: ffffe8ffffc2a1f8 RBX: ffffffff8e1ad790 RCX: 0000000000000102 RDX: ffffffff81767de5 RSI: ffffffff8c27b360 RDI: ffffffff8c27b320 RBP: ffffc90000006b80 R08: ffffc900000070d8 R09: 0000000000000000 R10: ffffc90000006d18 R11: fffff52000000da5 R12: dffffc0000000000 R13: 000000000000000d R14: ffffffff8e62a480 R15: 1ffff92000000d58 FS: 00007f56d1fb96c0(0000) GS:ffff888125463000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000004 CR3: 000000004abea000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __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:4542 [inline] slab_alloc_node mm/slub.c:4869 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4876 skb_ext_maybe_cow net/core/skbuff.c:7092 [inline] skb_ext_add+0x1b6/0x8f0 net/core/skbuff.c:7167 nf_bridge_unshare net/bridge/br_netfilter_hooks.c:169 [inline] br_nf_forward_ip+0xc3/0xa30 net/bridge/br_netfilter_hooks.c:681 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:316 __br_forward+0x397/0x540 net/bridge/br_forward.c:115 br_handle_frame_finish+0x14a3/0x1b70 net/bridge/br_input.c:229 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0xa3a/0xd70 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x374/0x6f0 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0x1277/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x98f/0x31a0 net/core/dev.c:6051 __netif_receive_skb_one_core net/core/dev.c:6162 [inline] __netif_receive_skb net/core/dev.c:6277 [inline] process_backlog+0x76d/0x1950 net/core/dev.c:6628 __napi_poll+0xae/0x340 net/core/dev.c:7692 napi_poll net/core/dev.c:7755 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7912 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+0x57/0x70 kernel/kcov.c:233 Code: 00 74 2c 8b 91 70 16 00 00 83 fa 02 75 21 48 8b 91 78 16 00 00 48 8b 32 48 8d 7e 01 8b 89 74 16 00 00 48 39 cf 73 08 48 89 3a <48> 89 44 f2 08 e9 8f 2a eb 09 cc 66 66 66 66 66 2e 0f 1f 84 00 00 RSP: 0018:ffffc9001032f3b8 EFLAGS: 00000287 RAX: ffffffff81f8f068 RBX: 0000000000000000 RCX: 0000000000080000 RDX: ffffc9001e547000 RSI: 00000000000003d1 RDI: 00000000000003d2 RBP: ffffc9001032f688 R08: ffffc9001032f497 R09: 0000000000000000 R10: ffffc9001032f488 R11: fffff52002065e93 R12: ffff88805c384608 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b86333d8 perf_tp_event+0x708/0x2a90 kernel/events/core.c:11406 perf_trace_run_bpf_submit+0xee/0x170 kernel/events/core.c:11337 do_perf_trace_lock_acquire include/trace/events/lock.h:24 [inline] perf_trace_lock_acquire+0x345/0x440 include/trace/events/lock.h:24 __do_trace_lock_acquire include/trace/events/lock.h:24 [inline] trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x2a4/0x2e0 kernel/locking/lockdep.c:5831 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [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 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:4542 [inline] slab_alloc_node mm/slub.c:4869 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4876 alloc_filename fs/namei.c:142 [inline] do_getname+0x2e/0x250 fs/namei.c:182 getname_flags fs/namei.c:225 [inline] class_filename_flags_constructor include/linux/fs.h:2541 [inline] user_path_at+0x2a/0x160 fs/namei.c:3611 do_mount fs/namespace.c:4169 [inline] __do_sys_mount fs/namespace.c:4361 [inline] __se_sys_mount+0x2dc/0x420 fs/namespace.c:4338 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: 0033:0x7f56d119c799 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:00007f56d1fb9028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f56d1415fa0 RCX: 00007f56d119c799 RDX: 0000200000000100 RSI: 0000200000000080 RDI: 0000000000000000 RBP: 00007f56d1232bd9 R08: 00002000000002c0 R09: 0000000000000000 R10: 0000000000010000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f56d1416038 R14: 00007f56d1415fa0 R15: 00007ffc7ab48cf8 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 10658 Comm: syz.6.12346 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 e6 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 cf e1 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 e1 RSP: 0018:ffffc900101ef440 EFLAGS: 00000293 RAX: ffffffff81b9bbfd RBX: 1ffff110170c8515 RCX: ffff88808a2a5b80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900101ef580 R08: ffffffff90118bb7 R09: 1ffffffff2023176 R10: dffffc0000000000 R11: fffffbfff2023177 R12: ffff8880b86428a8 R13: dffffc0000000000 R14: ffff8880b873bf80 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125563000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555853859e8 CR3: 000000000e54c000 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 __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+0x6a2/0x23c0 kernel/exit.c:964 do_group_exit+0x21b/0x2d0 kernel/exit.c:1118 get_signal+0x1284/0x1330 kernel/signal.c:3034 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f09d419c799 Code: Unable to access opcode bytes at 0x7f09d419c76f. RSP: 002b:00007f09d4fb5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: 0000000000000009 RBX: 00007f09d4415fa0 RCX: 00007f09d419c799 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000010 RBP: 00007f09d4232bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f09d4416038 R14: 00007f09d4415fa0 R15: 00007ffd9e41ddc8