INFO: task syz.3.11:4425 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.11 state:D stack:22112 pid:4425 ppid:4273 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 wait_on_state fs/btrfs/extent-io-tree.c:709 [inline] wait_extent_bit+0x3f1/0x550 fs/btrfs/extent-io-tree.c:742 lock_extent+0xcc/0x140 fs/btrfs/extent-io-tree.c:1657 find_lock_delalloc_range+0x371/0x680 fs/btrfs/extent_io.c:464 writepage_delalloc+0x107/0x370 fs/btrfs/extent_io.c:1965 __extent_writepage+0x596/0x15b0 fs/btrfs/extent_io.c:2276 extent_write_cache_pages fs/btrfs/extent_io.c:3191 [inline] extent_writepages+0x8f9/0x1410 fs/btrfs/extent_io.c:3313 do_writepages+0x3b7/0x610 mm/page-writeback.c:2491 filemap_fdatawrite_wbc+0x11e/0x180 mm/filemap.c:388 __filemap_fdatawrite_range mm/filemap.c:421 [inline] filemap_fdatawrite_range+0xca/0x120 mm/filemap.c:439 btrfs_fdatawrite_range fs/btrfs/file.c:3880 [inline] start_ordered_ops+0xe6/0x210 fs/btrfs/file.c:1742 btrfs_sync_file+0x420/0x11a0 fs/btrfs/file.c:1825 generic_write_sync include/linux/fs.h:2962 [inline] btrfs_do_write_iter+0xdd0/0x14e0 fs/btrfs/file.c:1691 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x44c/0x960 fs/read_write.c:584 ksys_write+0x143/0x240 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fcb1a58eec9 RSP: 002b:00007fcb1b458038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fcb1a7e5fa0 RCX: 00007fcb1a58eec9 RDX: 0000000000000003 RSI: 00002000000001c0 RDI: 0000000000000005 RBP: 00007fcb1a611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcb1a7e6038 R14: 00007fcb1a7e5fa0 R15: 00007ffe5e737bd8 INFO: task syz.3.11:4462 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.11 state:D stack:23848 pid:4462 ppid:4273 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 io_schedule+0x7c/0xd0 kernel/sched/core.c:8797 folio_wait_bit_common+0x6e1/0xf60 mm/filemap.c:1324 folio_wait_writeback+0xe9/0x1f0 mm/page-writeback.c:3058 btrfs_page_mkwrite+0x4fc/0xbf0 fs/btrfs/inode.c:8623 do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3011 wp_page_shared+0x167/0x370 mm/memory.c:3360 handle_pte_fault mm/memory.c:5049 [inline] __handle_mm_fault mm/memory.c:5173 [inline] handle_mm_fault+0x1ca6/0x3e70 mm/memory.c:5294 do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340 handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0010:copy_user_short_string+0xd/0x40 arch/x86/lib/copy_user_64.S:233 Code: 74 0a 89 d1 f3 a4 89 c8 0f 01 ca c3 89 d0 0f 01 ca c3 01 ca eb e7 90 90 90 90 90 90 90 89 d1 83 e2 07 c1 e9 03 74 12 4c 8b 06 <4c> 89 07 48 8d 76 08 48 8d 7f 08 ff c9 75 ee 21 d2 74 10 89 d1 8a RSP: 0018:ffffc9000508f428 EFLAGS: 00050202 RAX: ffffffff84071201 RBX: 0000000000000038 RCX: 0000000000000007 RDX: 0000000000000000 RSI: ffffc9000508f4c0 RDI: 00002000000002a0 RBP: 0000000000000000 R08: 0000000000000000 R09: fffff52000a11e9f R10: fffff52000a11e9f R11: 1ffff92000a11e98 R12: 00007fffffffefc8 R13: 1ffff92000a11e94 R14: 00002000000002a0 R15: ffffc9000508f4c0 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline] _copy_to_user+0xea/0x130 lib/usercopy.c:41 copy_to_user include/linux/uaccess.h:169 [inline] fiemap_fill_next_extent+0x19d/0x360 fs/ioctl.c:144 emit_fiemap_extent fs/btrfs/extent_io.c:3561 [inline] fiemap_process_hole+0x52c/0x1100 fs/btrfs/extent_io.c:3773 extent_fiemap+0xd1a/0x19b0 fs/btrfs/extent_io.c:-1 btrfs_fiemap+0x152/0x1b0 fs/btrfs/inode.c:8297 ioctl_fiemap fs/ioctl.c:219 [inline] do_vfs_ioctl+0x1425/0x1d10 fs/ioctl.c:810 __do_sys_ioctl fs/ioctl.c:868 [inline] __se_sys_ioctl+0x83/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fcb1a58eec9 RSP: 002b:00007fcb1b437038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fcb1a7e6090 RCX: 00007fcb1a58eec9 RDX: 0000200000000280 RSI: 00000000c020660b RDI: 0000000000000004 RBP: 00007fcb1a611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcb1a7e6128 R14: 00007fcb1a7e6090 R15: 00007ffe5e737bd8 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b570 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2bd90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 3 locks held by kworker/1:1/26: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90000a1fd00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:104 1 lock held by khungtaskd/28: #0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 3 locks held by kworker/1:2/126: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90002db7d00 (key_gc_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8cb308b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #2: ffffffff8cb308b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 3 locks held by klogd/3627: #0: ffff8880b8f3aad8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 #1: ffff8880b8f27848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: fs_reclaim_acquire+0x78/0x100 mm/page_alloc.c:4736 #2: ffff88807d4d0a18 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x5c/0x1080 kernel/sched/core.c:4111 1 lock held by dhcpcd/3933: #0: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x11f/0x6f0 net/netlink/af_netlink.c:2305 2 locks held by getty/4031: #0: ffff88814c9af098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 3 locks held by kworker/1:6/4334: #0: ffff88802f37f538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004827d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131 3 locks held by kworker/u4:6/4361: 3 locks held by kworker/u4:7/4374: #0: ffff888140e55138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900049dfd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff888078a180e0 (&type->s_umount_key#52){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:415 3 locks held by kworker/u4:10/4409: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004bdfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263 2 locks held by syz.3.11/4425: #0: ffff88807cf05768 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888078a18460 (sb_writers#14){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580 4 locks held by syz.3.11/4462: #0: ffff8880556c1920 (&sb->s_type->i_mutex_key#21){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline] #0: ffff8880556c1920 (&sb->s_type->i_mutex_key#21){++++}-{3:3}, at: btrfs_inode_lock+0x61/0xe0 fs/btrfs/inode.c:147 #1: ffff888076977958 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #1: ffff888076977958 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5322 [inline] #1: ffff888076977958 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5384 #2: ffff888078a18558 (sb_pagefaults#3){.+.+}-{0:0}, at: do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3011 #3: ffff8880556c17a8 (&ei->i_mmap_lock){++++}-{3:3}, at: btrfs_page_mkwrite+0x3f1/0xbf0 fs/btrfs/inode.c:8614 3 locks held by kworker/0:13/4497: #0: ffff88802f37f538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900053bfd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131 5 locks held by kworker/u4:14/5027: #0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900035e7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd34590 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594 #3: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe5/0xa50 net/core/dev.c:11489 #4: ffffffff8cb308b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #4: ffffffff8cb308b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962 4 locks held by udevd/5117: #0: ffff88804cca6d58 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182 #1: ffff888056105888 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x58/0x410 fs/kernfs/file.c:172 #2: ffff88804f2a92c0 (kn->active#5){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88804f2a92c0 (kn->active#5){.+.+}-{0:0}, at: kernfs_seq_start+0xae/0x410 fs/kernfs/file.c:173 #3: ffff88807cacc0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline] #3: ffff88807cacc0e8 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16c/0x320 drivers/base/core.c:2669 2 locks held by kworker/1:19/5452: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900049efd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 1 lock held by syz-executor/6673: #0: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x288/0x1af0 net/ipv4/devinet.c:1080 1 lock held by syz-executor/6781: #0: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6150 7 locks held by syz-executor/6821: #0: ffff88807ed6c460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580 #1: ffff888054d0c088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343 #2: ffff888144b7e490 (kn->active#54){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888144b7e490 (kn->active#54){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344 #3: ffffffff8d64c5e8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: new_device_store+0x129/0x670 drivers/net/netdevsim/bus.c:160 #4: ffff88807cacc0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline] #4: ffff88807cacc0e8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:990 #5: ffff88807cacd2f8 (&devlink->lock_key#17){+.+.}-{3:3}, at: nsim_drv_probe+0xc0/0xaf0 drivers/net/netdevsim/dev.c:1542 #6: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: register_nexthop_notifier+0x7d/0x210 net/ipv4/nexthop.c:3613 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4256 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:finish_task_switch+0x63/0x8f0 kernel/sched/core.c:5084 Code: 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 a4 84 78 00 4c 8b 23 49 8d 9c 24 f8 b4 03 00 49 89 df 49 c1 ef 03 43 80 3c 2f 00 <74> 08 48 89 df e8 83 84 78 00 48 8b 03 48 89 45 b8 65 8b 05 ad f7 RSP: 0018:ffffc90003bd7a18 EFLAGS: 00000046 RAX: 1ffffffff18bc931 RBX: ffff8880b8f3b4f8 RCX: 18c49e34058c5100 RDX: 0000000000000001 RSI: ffffffff8adefd00 RDI: ffffffff8adefcc0 RBP: ffffc90003bd7a70 R08: dffffc0000000000 R09: ffffed10053b6771 R10: ffffed10053b6771 R11: 1ffff110053b6770 R12: ffff8880b8f00000 R13: dffffc0000000000 R14: ffff888029db3b80 R15: 1ffff110171e769f FS: 000055558f56d500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564522192138 CR3: 000000002f281000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: context_switch kernel/sched/core.c:5247 [inline] __schedule+0x10f4/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 do_nanosleep+0x1a9/0x5f0 kernel/time/hrtimer.c:2088 hrtimer_nanosleep+0x15b/0x340 kernel/time/hrtimer.c:2136 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1314 [inline] __se_sys_clock_nanosleep+0x2e6/0x370 kernel/time/posix-timers.c:1291 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fbe9adc1743 Code: 1f 84 00 00 00 00 00 83 ff 03 74 7b 83 ff 02 b8 fa ff ff ff 49 89 ca 0f 44 f8 80 3d 1e 6e 1f 00 00 74 14 b8 e6 00 00 00 0f 05 d8 c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec 28 48 89 54 24 10 RSP: 002b:00007fff90ac7758 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbe9adc1743 RDX: 00007fff90ac7770 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00000000000000f4 R09: 001724af91efdcc4 R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff90ac7bc0 R13: 0000000000000004 R14: 00007fff90ac77ac R15: 00007fff90ac7840