ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 watchdog: BUG: soft lockup - CPU#0 stuck for 246s! [kworker/u8:27:8002] Modules linked in: irq event stamp: 14989268 hardirqs last enabled at (14989267): [] irqentry_exit+0x3b/0x90 kernel/entry/common.c:310 hardirqs last disabled at (14989268): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1050 softirqs last enabled at (14989266): [] softirq_handle_end kernel/softirq.c:425 [inline] softirqs last enabled at (14989266): [] handle_softirqs+0x5be/0x8e0 kernel/softirq.c:607 softirqs last disabled at (14989241): [] __do_softirq kernel/softirq.c:613 [inline] softirqs last disabled at (14989241): [] invoke_softirq kernel/softirq.c:453 [inline] softirqs last disabled at (14989241): [] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 CPU: 0 UID: 0 PID: 8002 Comm: kworker/u8:27 Not tainted 6.16.0-rc2-syzkaller-00082-gfb4d33ab452e #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+0xd7f/0x1510 kernel/smp.c:885 Code: 00 45 85 ed 74 46 48 8b 14 24 49 89 d6 49 89 d5 49 c1 ee 03 41 83 e5 07 4d 01 e6 41 83 c5 03 e8 57 1c 0c 00 f3 90 41 0f b6 06 <41> 38 c5 7c 08 84 c0 0f 85 6f 05 00 00 8b 43 08 31 ff 83 e0 01 89 RSP: 0018:ffffc90003a5e880 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b8541920 RCX: ffffffff81afff4d RDX: ffff888031e55a00 RSI: ffffffff81afff29 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000 R13: 0000000000000003 R14: ffffed10170a8325 R15: ffff8880b843d080 FS: 0000000000000000(0000) GS:ffff88812475a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000297030 CR3: 0000000068e08000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x4a0/0x1790 arch/x86/mm/tlb.c:1451 flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline] ptep_clear_flush+0x136/0x180 mm/pgtable-generic.c:101 page_vma_mkclean_one.constprop.0+0x3b4/0x7e0 mm/rmap.c:1059 page_mkclean_one+0x196/0x260 mm/rmap.c:1100 __rmap_walk_file+0x359/0x620 mm/rmap.c:2897 rmap_walk_file+0x174/0x1f0 mm/rmap.c:2930 rmap_walk mm/rmap.c:2941 [inline] folio_mkclean+0x251/0x3f0 mm/rmap.c:1132 folio_clear_dirty_for_io+0x153/0x810 mm/page-writeback.c:2964 mpage_submit_folio+0x80/0x3f0 fs/ext4/inode.c:2038 mpage_process_page_bufs+0x47c/0x9a0 fs/ext4/inode.c:2170 mpage_prepare_extent_to_map+0x756/0x1520 fs/ext4/inode.c:2675 ext4_do_writepages+0x9af/0x3490 fs/ext4/inode.c:2816 ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:2953 do_writepages+0x27a/0x600 mm/page-writeback.c:2636 __writeback_single_inode+0x160/0xfb0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x601/0xf90 fs/fs-writeback.c:1976 __writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2047 wb_writeback+0x7f3/0xb70 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+0x8ca/0xbe0 fs/fs-writeback.c:2343 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 24853 Comm: syz.3.5558 Not tainted 6.16.0-rc2-syzkaller-00082-gfb4d33ab452e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__timerqueue_less lib/timerqueue.c:22 [inline] RIP: 0010:rb_add_cached include/linux/rbtree.h:174 [inline] RIP: 0010:timerqueue_add+0xf0/0x330 lib/timerqueue.c:40 Code: 86 71 42 f6 4c 89 fa 48 c1 ea 03 42 80 3c 22 00 0f 85 ca 01 00 00 49 8b 17 48 85 d2 74 40 48 89 d3 e8 64 71 42 f6 48 8d 7b 18 <48> 89 f8 48 c1 e8 03 42 80 3c 20 00 0f 85 b1 01 00 00 4c 8b 7b 18 RSP: 0018:ffffc90000a08e00 EFLAGS: 00000046 RAX: 0000000000010001 RBX: ffff88804843b340 RCX: ffffffff8b79a978 RDX: ffff888032260000 RSI: ffffffff8b79aa1c RDI: ffff88804843b358 RBP: ffff88805a7fc340 R08: 0000000000000006 R09: ffff88805a7fc340 R10: ffff88805a7fc340 R11: ffffffff9af9d8e8 R12: dffffc0000000000 R13: 0000021f3f522ff2 R14: 0000000000000001 R15: 0000000000000001 FS: 00007fbd9d9c76c0(0000) GS:ffff88812485a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000281000 CR3: 0000000076623000 CR4: 0000000000350ef0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1778 [inline] __hrtimer_run_queues+0x8ff/0xad0 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5948 Code: 00 00 b8 ff ff ff ff 65 0f c1 05 ec 20 4f 08 83 f8 01 75 2d 9c 58 f6 c4 02 75 43 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f e9 02 c0 92 f5 45 31 ed eb RSP: 0018:ffffc9000ef9fc08 EFLAGS: 00000282 RAX: 0000000000000046 RBX: 1ffff92001df3f8a RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8ddf04fb RDI: ffffffff8c156620 RBP: ffffffff8e5c47c0 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff888032260000 R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000000 lock_is_held include/linux/lockdep.h:249 [inline] __might_resched+0x4ca/0x5e0 kernel/sched/core.c:8762 do_recvmmsg+0x51f/0x750 net/socket.c:2957 __sys_recvmmsg net/socket.c:2997 [inline] __do_sys_recvmmsg net/socket.c:3020 [inline] __se_sys_recvmmsg net/socket.c:3013 [inline] __x64_sys_recvmmsg+0x22a/0x280 net/socket.c:3013 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbd9cb8e929 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:00007fbd9d9c7038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fbd9cdb5fa0 RCX: 00007fbd9cb8e929 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007fbd9cc10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fbd9cdb5fa0 R15: 00007ffff13e9ca8