INFO: task syz.7.3909:20112 blocked for more than 143 seconds. Not tainted 6.16.0-rc3-syzkaller-00116-ge34a79b96ab9 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.3909 state:D stack:25800 pid:20112 tgid:20104 ppid:15729 task_flags:0x400040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 io_schedule+0xbf/0x130 kernel/sched/core.c:7723 folio_wait_bit_common+0x3d6/0x9e0 mm/filemap.c:1317 folio_lock include/linux/pagemap.h:1114 [inline] migrate_folio_unmap mm/migrate.c:1183 [inline] migrate_pages_batch+0x14d0/0x31a0 mm/migrate.c:1807 migrate_pages_sync+0x4c5/0x8a0 mm/migrate.c:1957 migrate_pages+0x1b67/0x23b0 mm/migrate.c:2039 compact_zone+0x2023/0x4760 mm/compaction.c:2683 compact_node+0x1a4/0x2d0 mm/compaction.c:2952 compact_nodes mm/compaction.c:2974 [inline] sysctl_compaction_handler mm/compaction.c:3025 [inline] sysctl_compaction_handler+0x141/0x210 mm/compaction.c:3012 proc_sys_call_handler+0x3c2/0x5c0 fs/proc/proc_sysctl.c:601 iter_file_splice_write+0x91f/0x1150 fs/splice.c:738 do_splice_from fs/splice.c:935 [inline] direct_splice_actor+0x192/0x6c0 fs/splice.c:1158 splice_direct_to_actor+0x342/0xa30 fs/splice.c:1102 do_splice_direct_actor fs/splice.c:1201 [inline] do_splice_direct+0x174/0x240 fs/splice.c:1227 do_sendfile+0xb06/0xe50 fs/read_write.c:1370 __do_sys_sendfile64 fs/read_write.c:1425 [inline] __se_sys_sendfile64 fs/read_write.c:1417 [inline] __x64_sys_sendfile64+0x154/0x220 fs/read_write.c:1417 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: 0033:0x7f60fbb8e929 RSP: 002b:00007f60f99b4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f60fbdb6160 RCX: 00007f60fbb8e929 RDX: 00002000000000c0 RSI: 0000000000000007 RDI: 0000000000000008 RBP: 00007f60fbc10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f60fbdb6160 R15: 00007ffcf81eb558 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5c4940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c4940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c4940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 2 locks held by getty/5573: #0: ffff8880374ea0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 6 locks held by kworker/1:6/5930: #0: ffff8880222b8948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000469fd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff8881463e7198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #2: ffff8881463e7198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fa0 drivers/usb/core/hub.c:5863 #3: ffff8881463fa510 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3220 [inline] #3: ffff8881463fa510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5432 [inline] #3: ffff8881463fa510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5675 [inline] #3: ffff8881463fa510 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5835 [inline] #3: ffff8881463fa510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2906/0x4fa0 drivers/usb/core/hub.c:5917 #4: ffff888145bbd068 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5433 [inline] #4: ffff888145bbd068 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5675 [inline] #4: ffff888145bbd068 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5835 [inline] #4: ffff888145bbd068 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x292b/0x4fa0 drivers/usb/core/hub.c:5917 #5: ffffffff8f930ab0 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x1a1/0x1cb0 drivers/usb/core/hub.c:3035 4 locks held by kworker/u8:29/13236: #0: ffff8880b843a2d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:614 [inline] #0: ffff8880b843a2d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:599 #1: ffffc9000437fd10 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff8880b8425b18 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x6b8/0xd30 kernel/time/timer.c:1117 #3: ffffffff9afee338 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x14c/0x4c0 lib/debugobjects.c:818 1 lock held by udevd/19652: #0: ffff888026ad7358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 1 lock held by syz.7.3909/20112: #0: ffff88805664a428 (sb_writers#3){.+.+}-{0:0}, at: splice_direct_to_actor+0x342/0xa30 fs/splice.c:1102 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc3-syzkaller-00116-ge34a79b96ab9 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 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: 13244 Comm: kworker/u8:37 Not tainted 6.16.0-rc3-syzkaller-00116-ge34a79b96ab9 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:__local_bh_enable_ip+0x87/0x120 kernel/softirq.c:402 Code: c0 74 57 9c 58 fa f6 c4 02 75 60 65 8b 05 01 f7 4f 12 25 00 ff 00 00 3d 00 02 00 00 74 54 83 eb 01 f7 db 65 01 1d e9 f6 4f 12 <65> 8b 05 e2 f6 4f 12 a9 00 ff ff 00 74 4d bf 01 00 00 00 e8 d1 00 RSP: 0018:ffffc9000425fa98 EFLAGS: 00000083 RAX: 0000000000000001 RBX: 00000000fffffe00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8ddf4bc3 RDI: ffffffff8c157ba0 RBP: ffffffff8b4db284 R08: 0000000000000001 R09: fffffbfff215026a R10: ffffffff90a81357 R11: 0000000000000001 R12: ffffffff8b4db630 R13: ffff888028f89640 R14: ffff888023744d80 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124752000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7a1a581178 CR3: 000000007f197000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000097 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_nc_purge_paths+0x1d4/0x3a0 net/batman-adv/network-coding.c:471 batadv_nc_worker+0x921/0x1030 net/batman-adv/network-coding.c:720 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245