watchdog: BUG: soft lockup - CPU#1 stuck for 143s! [syz.8.1080:10611] Modules linked in: irq event stamp: 11194281 hardirqs last enabled at (11194280): [] irqentry_exit+0x74/0x90 kernel/entry/common.c:357 hardirqs last disabled at (11194281): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1049 softirqs last enabled at (10264948): [] __do_softirq kernel/softirq.c:613 [inline] softirqs last enabled at (10264948): [] invoke_softirq kernel/softirq.c:453 [inline] softirqs last enabled at (10264948): [] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 softirqs last disabled at (10264951): [] __do_softirq kernel/softirq.c:613 [inline] softirqs last disabled at (10264951): [] invoke_softirq kernel/softirq.c:453 [inline] softirqs last disabled at (10264951): [] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 CPU: 1 UID: 0 PID: 10611 Comm: syz.8.1080 Not tainted 6.15.0-rc4-syzkaller-g9325d53fe9ad #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:arch_stack_walk+0x123/0x150 arch/x86/kernel/stacktrace.c:24 Code: 00 09 00 48 85 c0 74 24 48 89 df 48 89 c6 4d 89 f3 41 ff d3 0f 1f 00 84 c0 74 11 4c 89 ff e8 74 01 09 00 83 bd 78 ff ff ff 00 <75> cf 65 48 8b 05 33 c8 0c 11 48 3b 45 d8 75 12 48 83 c4 68 5b 41 RSP: 0018:ffffc90000a07d08 EFLAGS: 00000202 RAX: 0000000004edfa01 RBX: ffffc90000a07dc0 RCX: e18569ff2ca82100 RDX: 0000000000000004 RSI: ffffffff8d93592f RDI: ffff88801bf05a00 RBP: ffffc90000a07d90 R08: ffffc90000a079ef R09: 0000000000000000 R10: ffffc90000a079e0 R11: ffffffffa000085c R12: ffff88801bf05a00 R13: 1ffff92000141020 R14: ffffffff81acaa70 R15: ffffc90000a07d08 FS: 00007f57ae3e76c0(0000) GS:ffff8881261ca000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32adb000 CR3: 000000005346a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000200000000300 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:548 __call_rcu_common kernel/rcu/tree.c:3082 [inline] call_rcu+0x142/0x990 kernel/rcu/tree.c:3202 refdst_drop include/net/dst.h:263 [inline] skb_dst_drop include/net/dst.h:275 [inline] skb_release_head_state+0x71/0x250 net/core/skbuff.c:1146 skb_release_all net/core/skbuff.c:1160 [inline] __kfree_skb net/core/skbuff.c:1176 [inline] sk_skb_reason_drop+0xe9/0x170 net/core/skbuff.c:1214 kfree_skb_reason include/linux/skbuff.h:1279 [inline] kfree_skb include/linux/skbuff.h:1288 [inline] ip6_tnl_start_xmit+0xafd/0x1150 net/ipv6/ip6_tunnel.c:1458 __netdev_start_xmit include/linux/netdevice.h:5203 [inline] netdev_start_xmit include/linux/netdevice.h:5212 [inline] xmit_one net/core/dev.c:3776 [inline] dev_hard_start_xmit+0x2ff/0x880 net/core/dev.c:3792 __dev_queue_xmit+0x1adf/0x3a70 net/core/dev.c:4629 neigh_output include/net/neighbour.h:539 [inline] ip6_finish_output2+0x11fb/0x16a0 net/ipv6/ip6_output.c:141 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline] ip6_finish_output+0x234/0x7d0 net/ipv6/ip6_output.c:226 NF_HOOK include/linux/netfilter.h:314 [inline] ndisc_send_skb+0xb47/0x1400 net/ipv6/ndisc.c:513 addrconf_rs_timer+0x369/0x670 net/ipv6/addrconf.c:4038 call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1789 expire_timers kernel/time/timer.c:1840 [inline] __run_timers kernel/time/timer.c:2414 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2426 run_timer_base kernel/time/timer.c:2435 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2445 handle_softirqs+0x283/0x870 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 8b b1 6e f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 73 33 38 f6 65 8b 05 5c d5 1c 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc90004edf980 EFLAGS: 00000206 RAX: e18569ff2ca82100 RBX: 0000000000000a06 RCX: e18569ff2ca82100 RDX: 0000000000000000 RSI: ffffffff8d74a79b RDI: 0000000000000001 RBP: ffffc90004edfa10 R08: ffffffff8f7ed277 R09: 1ffffffff1efda4e R10: dffffc0000000000 R11: fffffbfff1efda4f R12: dffffc0000000000 R13: ffff88802dde6e38 R14: ffffffff99a3d680 R15: 1ffff920009dbf30 debug_object_activate+0x2e2/0x420 lib/debugobjects.c:836 debug_rcu_head_queue kernel/rcu/rcu.h:224 [inline] __call_rcu_common kernel/rcu/tree.c:3067 [inline] call_rcu+0x95/0x990 kernel/rcu/tree.c:3202 bpf_prog_put_deferred+0x2d8/0x3c0 kernel/bpf/syscall.c:2360 __bpf_prog_put kernel/bpf/syscall.c:2372 [inline] bpf_prog_put+0x25a/0x270 kernel/bpf/syscall.c:2379 bpf_prog_test_run+0x2e9/0x340 kernel/bpf/syscall.c:4431 __sys_bpf+0x4a4/0x860 kernel/bpf/syscall.c:5854 __do_sys_bpf kernel/bpf/syscall.c:5943 [inline] __se_sys_bpf kernel/bpf/syscall.c:5941 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5941 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f57ad58e969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f57ae3e7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f57ad7b5fa0 RCX: 00007f57ad58e969 RDX: 0000000000000048 RSI: 0000200000000600 RDI: 000000000000000a RBP: 00007f57ad610ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f57ad7b5fa0 R15: 00007fff5673c7c8 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8847 Comm: kworker/u8:16 Not tainted 6.15.0-rc4-syzkaller-g9325d53fe9ad #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: writeback wb_workfn (flush-8:0) RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xe69/0x11c0 kernel/smp.c:885 Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 20 6d 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 cb 68 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 b0 68 0b RSP: 0018:ffffc90003a4e0a0 EFLAGS: 00000293 RAX: ffffffff81b45620 RBX: ffff8880b883ad40 RCX: ffff88807f9b8000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003a4e200 R08: ffffffff8f7ed277 R09: 1ffffffff1efda4e R10: dffffc0000000000 R11: ffffffff816f3eb0 R12: 1ffff11017127e99 R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b893f4c8 FS: 0000000000000000(0000) GS:ffff8881260ca000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555557a9f5c8 CR3: 000000007b5ca000 CR4: 00000000003526f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff1 DR7: 0000000000000600 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1275 [inline] flush_tlb_mm_range+0x6ae/0x12b0 arch/x86/mm/tlb.c:1365 flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline] ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:101 page_vma_mkclean_one+0x406/0x740 mm/rmap.c:1059 page_mkclean_one+0x1a5/0x260 mm/rmap.c:1100 __rmap_walk_file+0x464/0x620 mm/rmap.c:2897 rmap_walk mm/rmap.c:2941 [inline] folio_mkclean+0x297/0x390 mm/rmap.c:1132 folio_clear_dirty_for_io+0x1fa/0x8c0 mm/page-writeback.c:2987 mpage_submit_folio+0x7d/0x2f0 fs/ext4/inode.c:1918 mpage_process_page_bufs+0x6d1/0xa00 fs/ext4/inode.c:2050 mpage_prepare_extent_to_map+0xe6e/0x16d0 fs/ext4/inode.c:2551 ext4_do_writepages+0x112e/0x3e50 fs/ext4/inode.c:2737 ext4_writepages+0x203/0x350 fs/ext4/inode.c:2829 do_writepages+0x3ae/0x7b0 mm/page-writeback.c:2656 __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x6b5/0x1000 fs/fs-writeback.c:1976 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047 wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158 wb_check_old_data_flush fs/fs-writeback.c:2262 [inline] wb_do_writeback fs/fs-writeback.c:2315 [inline] wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245