INFO: task kworker/u8:7:167 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:7 state:D stack:21280 pid:167 tgid:167 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-btrfs-39) Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 wait_extent_bit fs/btrfs/extent-io-tree.c:811 [inline] btrfs_lock_extent_bits+0x59c/0x700 fs/btrfs/extent-io-tree.c:1914 btrfs_lock_extent fs/btrfs/extent-io-tree.h:152 [inline] btrfs_invalidate_folio+0x43d/0xc40 fs/btrfs/inode.c:7718 extent_writepage fs/btrfs/extent_io.c:1852 [inline] extent_write_cache_pages fs/btrfs/extent_io.c:2580 [inline] btrfs_writepages+0x12ff/0x2440 fs/btrfs/extent_io.c:2713 do_writepages+0x32e/0x550 mm/page-writeback.c:2554 __writeback_single_inode+0x133/0x11a0 fs/fs-writeback.c:1762 writeback_sb_inodes+0x995/0x19d0 fs/fs-writeback.c:2054 wb_writeback+0x456/0xb70 fs/fs-writeback.c:2239 wb_do_writeback fs/fs-writeback.c:2386 [inline] wb_workfn+0x41a/0xf60 fs/fs-writeback.c:2426 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.5.866:10350 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.866 state:D stack:22560 pid:10350 tgid:10343 ppid:9004 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 wait_current_trans+0x39f/0x590 fs/btrfs/transaction.c:535 start_transaction+0x6a7/0x1650 fs/btrfs/transaction.c:705 clone_copy_inline_extent fs/btrfs/reflink.c:299 [inline] btrfs_clone+0x128a/0x24d0 fs/btrfs/reflink.c:529 btrfs_clone_files+0x271/0x3f0 fs/btrfs/reflink.c:750 btrfs_remap_file_range+0x76b/0x1320 fs/btrfs/reflink.c:903 vfs_clone_file_range+0x435/0x7b0 fs/remap_range.c:403 ioctl_file_clone fs/ioctl.c:239 [inline] ioctl_file_clone_range fs/ioctl.c:257 [inline] do_vfs_ioctl+0xe15/0x1540 fs/ioctl.c:544 __do_sys_ioctl fs/ioctl.c:595 [inline] __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff0dd0cc819 RSP: 002b:00007ff0db326028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff0dd345fa0 RCX: 00007ff0dd0cc819 RDX: 00002000000000c0 RSI: 000000004020940d RDI: 0000000000000008 RBP: 00007ff0dd162c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff0dd346038 R14: 00007ff0dd345fa0 R15: 00007fff0036b168 INFO: task syz.5.866:10437 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.866 state:D stack:24952 pid:10437 tgid:10343 ppid:9004 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 wb_wait_for_completion+0x3e8/0x790 fs/fs-writeback.c:227 __writeback_inodes_sb_nr+0x24c/0x2d0 fs/fs-writeback.c:2845 try_to_writeback_inodes_sb+0x9a/0xc0 fs/fs-writeback.c:2893 btrfs_start_delalloc_flush fs/btrfs/transaction.c:2175 [inline] btrfs_commit_transaction+0x82e/0x31a0 fs/btrfs/transaction.c:2364 btrfs_sync_file+0xdf2/0x1280 fs/btrfs/file.c:1817 vfs_fsync_range fs/sync.c:186 [inline] vfs_fsync fs/sync.c:200 [inline] do_fsync fs/sync.c:211 [inline] __do_sys_fdatasync fs/sync.c:221 [inline] __se_sys_fdatasync fs/sync.c:219 [inline] __x64_sys_fdatasync+0xbc/0x110 fs/sync.c:219 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff0dd0cc819 RSP: 002b:00007ff0d2ee4028 EFLAGS: 00000246 ORIG_RAX: 000000000000004b RAX: ffffffffffffffda RBX: 00007ff0dd346180 RCX: 00007ff0dd0cc819 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007ff0dd162c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff0dd346218 R14: 00007ff0dd346180 R15: 00007fff0036b168 Showing all locks held in the system: 8 locks held by ktimers/0/16: 1 lock held by khungtaskd/38: #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:7/167: #0: ffff88801f29d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801f29d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc900039f7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc900039f7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 3 locks held by kworker/u8:9/1104: #0: ffff88803240d938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88803240d938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc9000540fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc9000540fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f15cc78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f15cc78 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4198 3 locks held by kworker/u8:10/1170: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc900055efc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc900055efc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f15cc78 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 2 locks held by kworker/u8:11/1498: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc9000632fc40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc9000632fc40 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 2 locks held by udevd/5165: 1 lock held by dhcpcd/5460: #0: ffffffff8f15cc78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f15cc78 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x32b/0x1b30 net/ipv4/devinet.c:1120 2 locks held by getty/5553: #0: ffff888028cb60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 5 locks held by udevd/7669: 4 locks held by syz.5.866/10350: #0: ffff88801abec480 (sb_writers#25){.+.+}-{0:0}, at: ioctl_file_clone fs/ioctl.c:239 [inline] #0: ffff88801abec480 (sb_writers#25){.+.+}-{0:0}, at: ioctl_file_clone_range fs/ioctl.c:257 [inline] #0: ffff88801abec480 (sb_writers#25){.+.+}-{0:0}, at: do_vfs_ioctl+0xe15/0x1540 fs/ioctl.c:544 #1: ffff88805ff0ce78 (&sb->s_type->i_mutex_key#35){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff88805ff0ce78 (&sb->s_type->i_mutex_key#35){++++}-{4:4}, at: btrfs_inode_lock+0x51/0xe0 fs/btrfs/inode.c:369 #2: ffff88805ff0ccd8 (&ei->i_mmap_lock){++++}-{4:4}, at: btrfs_inode_lock+0xcb/0xe0 fs/btrfs/inode.c:372 #3: ffff88801abec770 (sb_internal#7){.+.+}-{0:0}, at: clone_copy_inline_extent fs/btrfs/reflink.c:299 [inline] #3: ffff88801abec770 (sb_internal#7){.+.+}-{0:0}, at: btrfs_clone+0x128a/0x24d0 fs/btrfs/reflink.c:529 3 locks held by syz.5.866/10437: #0: ffff888056ad7118 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x41b/0xc90 fs/btrfs/transaction.c:298 #1: ffff888056ad7140 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x41b/0xc90 fs/btrfs/transaction.c:298 #2: ffff88801abec0d0 (&type->s_umount_key#77){++++}-{4:4}, at: try_to_writeback_inodes_sb+0x22/0xc0 fs/fs-writeback.c:2890 1 lock held by udevd/10404: 1 lock held by btrfs-transacti/10418: #0: ffff888056ad4d98 (&fs_info->transaction_kthread_mutex){+.+.}-{4:4}, at: transaction_kthread+0xe4/0x450 fs/btrfs/disk-io.c:1515 4 locks held by kworker/u8:2/10955: 1 lock held by syz-executor/12199: #0: ffffffff8f15cc78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f15cc78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f15cc78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4093 7 locks held by syz-executor/12336: #0: ffff888037bd8480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #0: ffff888037bd8480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff88805e5b0878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff888028e25788 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888028e25788 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e9c9e18 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 #4: ffff88803eb09160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #4: ffff88803eb09160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1166 [inline] #4: ffff88803eb09160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1364 #5: ffff888026a54300 (&devlink->lock_key#21){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1778 #6: ffffffff8f15cc78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8f15cc78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2162 8 locks held by syz.7.1148/12508: 2 locks held by syz.6.1149/12510: 2 locks held by syz.9.1150/12512: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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:161 [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:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 1815 Comm: kworker/0:3 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: events_power_efficient wg_ratelimiter_gc_entries RIP: 0010:__lock_acquire+0x30c/0x2cf0 kernel/locking/lockdep.c:5176 Code: 10 31 f6 85 d2 40 0f 95 c6 31 d2 41 83 be 9c 0b 00 00 00 0f 95 c2 c1 e2 0d c1 e6 0e 09 d6 8b 54 24 20 c1 e2 0f 0f b7 d2 09 f2 <41> 83 e5 03 41 c1 e5 10 41 09 d5 8b 54 24 10 83 e2 01 c1 e2 12 44 RSP: 0018:ffffc9000688f800 EFLAGS: 00000046 RAX: 000000000000000f RBX: 0000000000000000 RCX: 000000000000000b RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000003 R08: ffffffff8b2611d0 R09: ffffffff8ddcb9c0 R10: dffffc0000000000 R11: fffffbfff1ed4d77 R12: 0000000000000000 R13: 0000000000000002 R14: ffff88802a6f3d00 R15: ffff88802a6f48b8 FS: 0000000000000000(0000) GS:ffff888126336000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f948929c000 CR3: 000000005cf3e000 CR4: 00000000003526f0 Call Trace: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] rt_spin_lock+0x1fc/0x400 kernel/locking/spinlock_rt.c:57 spin_lock include/linux/spinlock_rt.h:45 [inline] wg_ratelimiter_gc_entries+0x5d/0x480 drivers/net/wireguard/ratelimiter.c:63 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245