INFO: task kworker/u8:10:1444 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:10 state:D stack:21304 pid:1444 tgid:1444 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-7:6) Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7228 __schedule_loop kernel/sched/core.c:7307 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7603 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1670 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline] __rt_mutex_slowlock_locked+0x1f84/0x25b0 kernel/locking/rtmutex.c:1787 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1827 __rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline] rwbase_write_lock+0x14c/0x720 kernel/locking/rwbase_rt.c:251 f2fs_down_write fs/f2fs/f2fs.h:2411 [inline] f2fs_down_write_trace fs/f2fs/checkpoint.c:180 [inline] f2fs_issue_checkpoint+0x407/0x770 fs/f2fs/checkpoint.c:2095 f2fs_write_node_pages+0x158/0x700 fs/f2fs/node.c:2257 do_writepages+0x338/0x560 mm/page-writeback.c:2571 __writeback_single_inode+0x12e/0xf90 fs/fs-writeback.c:1787 writeback_sb_inodes+0x9db/0x1ab0 fs/fs-writeback.c:2079 __writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2155 wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2266 wb_check_old_data_flush fs/fs-writeback.c:2370 [inline] wb_do_writeback fs/fs-writeback.c:2449 [inline] wb_workfn+0xc98/0x10f0 fs/fs-writeback.c:2477 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: lockdep is turned off. NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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: 19606 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:arch_try_cmpxchg128 arch/x86/include/asm/cmpxchg_64.h:83 [inline] RIP: 0010:__update_freelist_fast mm/slub.c:652 [inline] RIP: 0010:slab_update_freelist mm/slub.c:718 [inline] RIP: 0010:__slab_free+0xbc/0x2a0 mm/slub.c:5623 Code: 4d 85 e4 89 44 24 1c 74 3c 85 c0 74 38 45 31 ed f6 43 0a 20 74 5a 48 8b 44 24 40 48 8b 54 24 48 48 8b 5c 24 30 48 8b 4c 24 38 49 0f c7 4e 20 0f 84 d0 00 00 00 48 89 44 24 40 48 89 54 24 48 RSP: 0018:ffffc9000668f3f0 EFLAGS: 00000202 RAX: ffff88803b5a5c00 RBX: ffff88803b5a5a00 RCX: 000000080010000e RDX: 000000080010000f RSI: ffff88803b5a5a00 RDI: ffff88801a027c80 RBP: ffffc9000668f478 R08: 0000000000000001 R09: ffffffff822dfefe R10: dffffc0000000000 R11: fffffbfff1f125df R12: ffff88803b5a5c00 R13: 0000000000000000 R14: ffffea0000ed6900 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812625c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb1485f0a10 CR3: 0000000052226000 CR4: 00000000003526f0 Call Trace: qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4610 [inline] slab_alloc_node mm/slub.c:4939 [inline] kmem_cache_alloc_noprof+0x337/0x680 mm/slub.c:4946 vm_area_alloc+0x24/0x140 mm/vma_init.c:32 __mmap_new_vma mm/vma.c:2547 [inline] __mmap_region mm/vma.c:2771 [inline] mmap_region+0x11e7/0x2340 mm/vma.c:2857 do_mmap+0xc1e/0x10b0 mm/mmap.c:560 vm_mmap_pgoff+0x275/0x4e0 mm/util.c:581 ksys_mmap_pgoff+0x4a6/0x720 mm/mmap.c:606 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb14891d242 Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00 RSP: 002b:00007ffc47a95c48 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fb14858b000 RCX: 00007fb14891d242 RDX: 0000000000000005 RSI: 0000000000037000 RDI: 00007fb14858b000 RBP: 0000000000000812 R08: 0000000000000003 R09: 0000000000003000 R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffc47a95c98 R13: 00007fb1485f46b0 R14: 00007ffc47a96080 R15: 00000fff88f52b8c