INFO: task syz.1.902:9130 blocked for more than 143 seconds. Tainted: G L syzkaller #0 Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.902 state:D stack:25752 pid:9130 tgid:9130 ppid:5615 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x16ec/0x5620 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7564 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1662 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1739 [inline] __rt_mutex_slowlock_locked+0x1f28/0x2550 kernel/locking/rtmutex.c:1779 __rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1496 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1570 filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline] do_page_cache_ra mm/readahead.c:333 [inline] page_cache_ra_order+0x2a5/0x490 mm/readahead.c:538 do_sync_mmap_readahead+0x570/0x6a0 mm/filemap.c:3406 filemap_fault+0x70c/0x1310 mm/filemap.c:3555 __do_fault+0x138/0x2a0 mm/memory.c:5474 do_shared_fault mm/memory.c:5973 [inline] do_fault mm/memory.c:6047 [inline] do_pte_missing+0x65b/0x2950 mm/memory.c:4566 handle_pte_fault mm/memory.c:6427 [inline] __handle_mm_fault mm/memory.c:6565 [inline] handle_mm_fault+0xd30/0x1400 mm/memory.c:6734 do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7fe40d0fbd18 RSP: 002b:00007ffd8f796398 EFLAGS: 00010202 RAX: 0000200000000040 RBX: 0000000000000004 RCX: 0030626c6c756e2f RDX: 000000000000000c RSI: 6c756e2f7665642f RDI: 0000200000000040 RBP: fffffffffffffffe R08: 0000001b32320000 R09: 0000000000000001 R10: 7ffffffffffffff3 R11: 0000000000000009 R12: 00007ffd8f7964c0 R13: 00007fe40d3a5fac R14: 0000000000062b05 R15: 00007fe40d3a5fa0 Showing all locks held in the system: 5 locks held by kworker/0:1/10: #0: ffff88801d6f2538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88801d6f2538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc900000f7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc900000f7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffff88802a142210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88802a142210 (&dev->mutex){....}-{4:4}, at: hub_event+0x17c/0x4f60 drivers/usb/core/hub.c:5899 #3: ffff88802a4fc210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #3: ffff88802a4fc210 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xde/0x970 drivers/usb/core/hub.c:2336 #4: ffff888067e601d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #4: ffff888067e601d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1174 [inline] #4: ffff888067e601d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1372 4 locks held by pr/legacy/17: 9 locks held by ksoftirqd/1/30: #0: ffffffff8de5f1c0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #1: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #2: ffff8880b893af98 (&pool->cb_lock){+...}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffff8880b893af98 (&pool->cb_lock){+...}-{3:3}, at: worker_lock_callback kernel/workqueue.c:3136 [inline] #2: ffff8880b893af98 (&pool->cb_lock){+...}-{3:3}, at: bh_worker+0x7b/0x880 kernel/workqueue.c:3680 #3: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #3: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #4: ffff88801a035938 ((wq_completion)events_bh_highpri){+...}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #4: ffff88801a035938 ((wq_completion)events_bh_highpri){+...}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #5: ffffc90000a4fb80 ((work_completion)(&bh->bh)){+...}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #5: ffffc90000a4fb80 ((work_completion)(&bh->bh)){+...}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #6: ffff88802a0234a8 (&hub->irq_urb_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #6: ffff88802a0234a8 (&hub->irq_urb_lock){+.+.}-{3:3}, at: hub_resubmit_irq_urb+0x29/0x160 drivers/usb/core/hub.c:683 #7: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #7: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #7: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #7: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #8: ffffffff8ec0c0b8 (hcd_root_hub_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #8: ffffffff8ec0c0b8 (hcd_root_hub_lock){+.+.}-{3:3}, at: rh_queue_status drivers/usb/core/hcd.c:785 [inline] #8: ffffffff8ec0c0b8 (hcd_root_hub_lock){+.+.}-{3:3}, at: rh_urb_enqueue drivers/usb/core/hcd.c:813 [inline] #8: ffffffff8ec0c0b8 (hcd_root_hub_lock){+.+.}-{3:3}, at: usb_hcd_submit_urb+0x261/0x1b50 drivers/usb/core/hcd.c:1536 2 locks held by kdevtmpfs/33: #0: ffff88801c6d4480 (sb_writers){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88801b6b4e38 (&type->i_mutex_dir_key/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline] #1: ffff88801b6b4e38 (&type->i_mutex_dir_key/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2914 [inline] #1: ffff88801b6b4e38 (&type->i_mutex_dir_key/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2938 [inline] #1: ffff88801b6b4e38 (&type->i_mutex_dir_key/1){+.+.}-{4:4}, at: __start_removing_path+0x1bc/0x310 fs/namei.c:2973 1 lock held by khungtaskd/38: #0: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:3/56: 5 locks held by kworker/u8:4/67: 2 locks held by getty/5364: #0: ffff888036d300a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 7 locks held by kworker/1:3/5710: 1 lock held by udevd/5867: 4 locks held by udevd/6044: 2 locks held by syz.3.881/9054: 1 lock held by syz.1.902/9130: #0: ffff888026362598 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline] #0: ffff888026362598 (mapping.invalidate_lock){++++}-{4:4}, at: do_page_cache_ra mm/readahead.c:333 [inline] #0: ffff888026362598 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x2a5/0x490 mm/readahead.c:538 4 locks held by kworker/u8:5/9340: 1 lock held by syz.2.1115/9910: #0: ffff8880263623c8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #0: ffff8880263623c8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:907 1 lock held by syz.4.1117/9917: #0: ffff8880263623c8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #0: ffff8880263623c8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:907 1 lock held by syz.0.1118/9921: #0: ffff8880263623c8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #0: ffff8880263623c8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:907 4 locks held by syz-executor/10032: 1 lock held by syz-executor/10057: #0: ffff88806c34c480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 2 locks held by syz-executor/10063: 7 locks held by syz.6.1250/10516: 4 locks held by syz.5.1259/10545: #0: ffffffff8f3c05e0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8f3c03f8 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8f3c03f8 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8f3c03f8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 #2: ffff888036bfd178 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff888036bfd178 (&dev->mutex){....}-{4:4}, at: nfc_dev_up+0x3f/0x350 net/nfc/core.c:95 #3: ffff888029b70400 (&ndev->req_lock){+.+.}-{4:4}, at: nci_open_device net/nfc/nci/core.c:478 [inline] #3: ffff888029b70400 (&ndev->req_lock){+.+.}-{4:4}, at: nci_dev_up+0xa3/0xdd0 net/nfc/nci/core.c:643 3 locks held by syz-executor/10549: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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: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+0xfd3/0x1030 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 17 Comm: pr/legacy Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401 Code: e8 2e 1b 90 fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 4f 48 f7 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 0a 0a eb 05 cc 44 89 f9 80 e1 07 RSP: 0000:ffffc900001679d0 EFLAGS: 00000202 RAX: 1ffffffff3360d00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff99b06bb0 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff853451d0 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff99b06920 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888126187000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f326d5bdd58 CR3: 000000006f8f6000 CR4: 00000000003526f0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:128 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline] wait_for_lsr+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1973 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3210 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3275 [inline] serial8250_console_write+0x120d/0x1b90 drivers/tty/serial/8250/8250_port.c:3360 console_emit_next_record kernel/printk/printk.c:3163 [inline] console_flush_one_record+0x68b/0xb90 kernel/printk/printk.c:3269 legacy_kthread_func+0x1b6/0x250 kernel/printk/printk.c:3712 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