watchdog: BUG: soft lockup - CPU#1 stuck for 205s! [kworker/u4:13:2294]
Modules linked in:
CPU: 1 PID: 2294 Comm: kworker/u4:13 Tainted: G        W          syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:csd_lock_wait kernel/smp.c:453 [inline]
RIP: 0010:smp_call_function_many_cond+0x854/0x940 kernel/smp.c:998
Code: 41 8b 1f 89 de 83 e6 01 31 ff e8 77 72 09 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 0a e8 43 6e 09 00 e9 38 ff ff ff f3 90 <41> 0f b6 44 1d 00 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 1a ff ff
RSP: 0018:ffffc90000a065e0 EFLAGS: 00000293
RAX: ffffffff8167f820 RBX: dffffc0000000000 RCX: ffff888113799440
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000a06720 R08: ffffc90000a06567 R09: 1ffff92000140cac
R10: dffffc0000000000 R11: fffff52000140cad R12: 1ffff1103ede7218
R13: 1ffff1103edc7ae1 R14: 0000000000000000 R15: ffff8881f6e3d708
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f19d12146f8 CR3: 000000000700f000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x43/0x80 kernel/smp.c:1165
 native_flush_tlb_multi+0x144/0x210 arch/x86/mm/tlb.c:-1
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:87 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:970 [inline]
 flush_tlb_mm_range+0x36a/0x470 arch/x86/mm/tlb.c:1058
 flush_tlb_page arch/x86/include/asm/tlbflush.h:241 [inline]
 ptep_clear_flush+0x111/0x150 mm/pgtable-generic.c:99
 page_vma_mkclean_one+0x3bf/0x580 mm/rmap.c:976
 page_mkclean_one+0x18d/0x240 mm/rmap.c:1024
 rmap_walk_file+0x5ab/0x8b0 mm/rmap.c:2529
 rmap_walk mm/rmap.c:2547 [inline]
 folio_mkclean+0x182/0x210 mm/rmap.c:1056
 folio_clear_dirty_for_io+0x130/0x5b0 mm/page-writeback.c:2889
 clear_page_dirty_for_io+0x55/0x70 mm/folio-compat.c:74
 mpage_submit_page+0x8a/0x220 fs/ext4/inode.c:2125
 mpage_process_page_bufs+0x6dd/0x8d0 fs/ext4/inode.c:2259
 mpage_prepare_extent_to_map+0x936/0xc50 fs/ext4/inode.c:2684
 ext4_writepages+0xbfb/0x30a0 fs/ext4/inode.c:2812
 do_writepages+0x3ab/0x600 mm/page-writeback.c:2494
 __writeback_single_inode+0xd9/0xb10 fs/fs-writeback.c:1622
 writeback_sb_inodes+0x9fd/0x1610 fs/fs-writeback.c:1913
 __writeback_inodes_wb+0x127/0x400 fs/fs-writeback.c:1984
 wb_writeback+0x3ff/0x990 fs/fs-writeback.c:2091
 wb_check_background_flush fs/fs-writeback.c:2161 [inline]
 wb_do_writeback fs/fs-writeback.c:2249 [inline]
 wb_workfn+0xae6/0xeb0 fs/fs-writeback.c:2276
 process_one_work+0x717/0xc30 kernel/workqueue.c:2302
 worker_thread+0xa4d/0x11d0 kernel/workqueue.c:2449
 kthread+0x281/0x320 kernel/kthread.c:386
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4544 Comm: syz.0.1053 Tainted: G        W          syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:native_halt arch/x86/include/asm/irqflags.h:57 [inline]
RIP: 0010:halt arch/x86/include/asm/irqflags.h:98 [inline]
RIP: 0010:kvm_wait+0xdf/0x150 arch/x86/kernel/kvm.c:1058
Code: 43 c6 44 37 04 f8 75 24 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 48 0f b6 07 40 38 f0 75 93 66 90 0f 00 2d f2 1b 33 04 f4 <eb> 87 fa 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 3f 0f b6 07
RSP: 0018:ffffc900029b7480 EFLAGS: 00000046
RAX: 0000000000000003 RBX: ffff888112961220 RCX: ffffffff85012029
RDX: dffffc0000000000 RSI: 0000000000000003 RDI: ffff888112961220
RBP: ffffc900029b7510 R08: ffff888112961220 R09: 1ffff1102252c244
R10: dffffc0000000000 R11: ffffed102252c245 R12: 1ffff1102252c244
R13: ffff8881f6e38cd4 R14: dffffc0000000000 R15: 1ffff92000536e90
FS:  00007f99a694f6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c31ac88 CR3: 000000012ab38000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 pv_wait arch/x86/include/asm/paravirt.h:603 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
 __pv_queued_spin_lock_slowpath+0x687/0xc40 kernel/locking/qspinlock.c:511
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline]
 queued_spin_lock_slowpath+0x47/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock include/linux/spinlock.h:187 [inline]
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0x120/0x130 kernel/locking/spinlock.c:162
 __wake_up_common_lock kernel/sched/wait.c:138 [inline]
 __wake_up+0x107/0x1a0 kernel/sched/wait.c:161
 __io_cqring_wake io_uring/io_uring.h:225 [inline]
 io_req_local_work_add io_uring/io_uring.c:1133 [inline]
 __io_req_task_work_add+0x4a9/0x8a0 io_uring/io_uring.c:1144
 io_req_task_work_add io_uring/io_uring.h:87 [inline]
 __io_poll_execute+0xd1/0x210 io_uring/poll.c:391
 io_poll_wake+0x369/0x460 io_uring/poll.c:466
 __wake_up_common+0x261/0x470 kernel/sched/wait.c:108
 __wake_up_common_lock kernel/sched/wait.c:139 [inline]
 __wake_up+0x121/0x1a0 kernel/sched/wait.c:161
 __io_cqring_wake io_uring/io_uring.h:225 [inline]
 io_cqring_wake io_uring/io_uring.h:232 [inline]
 io_cqring_ev_posted io_uring/io_uring.c:563 [inline]
 __io_cq_unlock_post io_uring/io_uring.c:571 [inline]
 io_cq_unlock_post io_uring/io_uring.c:588 [inline]
 io_req_complete_post+0x732/0xb00 io_uring/io_uring.c:862
 io_req_complete_failed io_uring/io_uring.c:881 [inline]
 io_queue_async+0x23e/0x800 io_uring/io_uring.c:1904
 io_queue_sqe io_uring/io_uring.c:1934 [inline]
 io_submit_sqe io_uring/io_uring.c:2193 [inline]
 io_submit_sqes+0xdff/0x1ba0 io_uring/io_uring.c:2306
 __do_sys_io_uring_enter io_uring/io_uring.c:3430 [inline]
 __se_sys_io_uring_enter+0x32c/0x1f50 io_uring/io_uring.c:3362
 __x64_sys_io_uring_enter+0xe5/0x100 io_uring/io_uring.c:3362
 x64_sys_call+0x4b2/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:427
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f99a599e019
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:00007f99a694ef38 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 0000200000000340 RCX: 00007f99a599e019
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000003
RBP: 0000000000000159 R08: 0000000000000000 R09: 0000000000000008
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000000a0
R13: 00000000000000a8 R14: 0000000000000e26 R15: 0000000000000001
 </TASK>