watchdog: BUG: soft lockup - CPU#0 stuck for 120s! [syz-executor:4791] Modules linked in: irq event stamp: 169110 hardirqs last enabled at (169109): [] asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 hardirqs last disabled at (169110): [] sysvec_apic_timer_interrupt+0xa/0xc0 arch/x86/kernel/apic/apic.c:1108 softirqs last enabled at (169108): [] __do_softirq kernel/softirq.c:610 [inline] softirqs last enabled at (169108): [] invoke_softirq kernel/softirq.c:450 [inline] softirqs last enabled at (169108): [] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659 softirqs last disabled at (163127): [] __do_softirq kernel/softirq.c:610 [inline] softirqs last disabled at (163127): [] invoke_softirq kernel/softirq.c:450 [inline] softirqs last disabled at (163127): [] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659 CPU: 0 PID: 4791 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_many_cond+0xb88/0xd70 kernel/smp.c:969 Code: b6 44 05 00 84 c0 0f 85 9d 00 00 00 41 8b 1c 24 89 de 83 e6 01 31 ff e8 66 49 0b 00 83 e3 01 75 07 e8 fc 45 0b 00 eb 43 f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 11 41 f7 RSP: 0018:ffffc90002fbf4e0 EFLAGS: 00000293 RAX: ffffffff816c84bb RBX: 0000000000000001 RCX: ffff8880183d3b80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90002fbf620 R08: dffffc0000000000 R09: fffffbfff183bff8 R10: fffffbfff183bff8 R11: 1ffffffff183bff7 R12: ffff8880b91405c8 R13: 1ffff110172280b9 R14: ffff8880b903b3c0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f514162fff8 CR3: 000000000be8e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1134 __flush_tlb_multi arch/x86/include/asm/paravirt.h:87 [inline] flush_tlb_multi arch/x86/mm/tlb.c:946 [inline] flush_tlb_mm_range+0x360/0x560 arch/x86/mm/tlb.c:1034 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly+0x1b1/0x3f0 include/asm-generic/tlb.h:430 tlb_flush_mmu mm/mmu_gather.c:246 [inline] tlb_finish_mmu+0xc5/0x2e0 mm/mmu_gather.c:338 exit_mmap+0x3a6/0x5f0 mm/mmap.c:3218 __mmput+0x115/0x3b0 kernel/fork.c:1127 exit_mm+0x567/0x6c0 kernel/exit.c:550 do_exit+0x5a1/0x20a0 kernel/exit.c:870 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fa25a9c1a3c Code: Unable to access opcode bytes at RIP 0x7fa25a9c1a12. RSP: 002b:00007ffde503c950 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: fffffffffffffe00 RBX: 0000000000000003 RCX: 00007fa25a9c1a3c RDX: 0000000000000028 RSI: 00007ffde503ca00 RDI: 00000000000000f9 RBP: 00007ffde503c9ac R08: 0000000000000000 R09: 0079746972756365 R10: 00007fa25ab4d7e0 R11: 0000000000000246 R12: 0000000000000061 R13: 000000000001985a R14: 000000000001950d R15: 00007ffde503ca00 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 144 Comm: kworker/u4:1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: writeback wb_workfn (flush-8:0) RIP: 0010:__preempt_count_add arch/x86/include/asm/preempt.h:80 [inline] RIP: 0010:rcu_is_watching+0x5/0xa0 kernel/rcu/tree.c:1122 Code: 65 e8 5b 41 5e 41 5f 5d c3 e8 47 9e 45 08 41 f7 c7 00 02 00 00 75 b8 eb b7 e8 27 9e 45 08 0f 1f 80 00 00 00 00 41 57 41 56 53 <65> ff 05 0c c0 9e 7e e8 1f ae 45 08 89 c3 83 f8 08 73 5c 49 bf 00 RSP: 0018:ffffc90000dd0c60 EFLAGS: 00000002 RAX: ffffffff88095c6a RBX: 0000000000000001 RCX: ffff88801b60d940 RDX: 0000000000010000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff888020553360 R08: dffffc0000000000 R09: fffffbfff1ff7a19 R10: fffffbfff1ff7a19 R11: 1ffffffff1ff7a18 R12: ffff8880205532e8 R13: dffffc0000000000 R14: ffff888020553000 R15: 000000254f6a6a20 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000600 CR3: 000000007b4fd000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock include/linux/rcupdate.h:741 [inline] advance_sched+0x6e3/0x940 net/sched/sch_taprio.c:769 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:clear_page_dirty_for_io+0x785/0x9e0 mm/page-writeback.c:2762 Code: 41 73 d8 ff 49 ff ce e9 5b fe ff ff e8 34 73 d8 ff e8 7f f6 09 08 48 85 db 0f 84 53 ff ff ff e8 21 73 d8 ff fb 48 8b 7c 24 10 06 00 00 00 e8 e1 de 06 00 48 c7 c0 70 9c 69 8d 48 c1 e8 03 42 RSP: 0018:ffffc9000167ec40 EFLAGS: 00000293 RAX: ffffffff819f576f RBX: 0000000000000200 RCX: ffff88801b60d940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea0001c76e40 RBP: ffffc9000167ed28 R08: dffffc0000000000 R09: fffffbfff1ff7a31 R10: fffffbfff1ff7a31 R11: 1ffffffff1ff7a30 R12: ffff8880237b0060 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000 mpage_submit_page+0x8a/0x210 fs/ext4/inode.c:2093 mpage_process_page_bufs+0x6d8/0x8b0 fs/ext4/inode.c:2227 mpage_prepare_extent_to_map+0xb7d/0xf70 fs/ext4/inode.c:2655 ext4_writepages+0xa09/0x2d20 fs/ext4/inode.c:2783 do_writepages+0x48d/0x6d0 mm/page-writeback.c:2386 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657 writeback_sb_inodes+0x9fe/0x1610 fs/fs-writeback.c:1940 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:2011 wb_writeback+0x455/0xb90 fs/fs-writeback.c:2116 wb_check_old_data_flush fs/fs-writeback.c:2216 [inline] wb_do_writeback fs/fs-writeback.c:2269 [inline] wb_workfn+0xaaa/0xe60 fs/fs-writeback.c:2298 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287