INFO: task syz.5.135:5467 blo INFO: task syz.5.135:5467 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.135 state:D stack:0 pid:5467 tgid:5466 ppid:5191 task_flags:0x400040 flags:0x00000011 Call trace: __switch_to+0x2b0/0x6e0 arch/arm64/kernel/process.c:810 (T) context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1c04/0x2db8 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x13c/0x20c kernel/sched/core.c:7283 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x4fc/0xed0 kernel/locking/mutex.c:820 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:873 sync_bdevs+0x214/0x3d4 block/bdev.c:1296 ksys_sync+0xc4/0x118 fs/sync.c:105 __arm64_sys_sync+0x14/0x24 fs/sync.c:111 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 INFO: task syz.5.135:5469 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.135 state:D stack:0 pid:5469 tgid:5466 ppid:5191 task_flags:0x400040 flags:0x00800011 Call trace: __switch_to+0x2b0/0x6e0 arch/arm64/kernel/process.c:810 (T) context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1c04/0x2db8 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x13c/0x20c kernel/sched/core.c:7283 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x4fc/0xed0 kernel/locking/mutex.c:820 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:873 sync_bdevs+0x214/0x3d4 block/bdev.c:1296 ksys_sync+0xc4/0x118 fs/sync.c:105 __arm64_sys_sync+0x14/0x24 fs/sync.c:111 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffff800088bf70c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff800088bf70c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffff800088bf70c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x4c/0x188 kernel/locking/lockdep.c:6775 2 locks held by pr/ttyAMA-1/41: 2 locks held by kworker/0:2/867: 2 locks held by getty/4487: #0: ffff0000ceddc0a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340 #1: ffff8000923ab2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x348/0xf70 drivers/tty/n_tty.c:2211 1 lock held by udevd/4698: #0: ffff0000c802c350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xc4/0x880 block/bdev.c:953 4 locks held by kworker/0:4/4718: #0: ffff0000c002b540 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff0000c002b540 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x734/0x10b8 kernel/workqueue.c:3397 #1: ffff800094507c40 ((work_completion)(&helper->damage_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #1: ffff800094507c40 ((work_completion)(&helper->damage_work)){+.+.}-{0:0}, at: process_scheduled_works+0x73c/0x10b8 kernel/workqueue.c:3397 #2: ffff0000c7019270 (&helper->lock){+.+.}-{4:4}, at: drm_fb_helper_fb_dirty drivers/gpu/drm/drm_fb_helper.c:236 [inline] #2: ffff0000c7019270 (&helper->lock){+.+.}-{4:4}, at: drm_fb_helper_damage_work+0xf4/0x5e4 drivers/gpu/drm/drm_fb_helper.c:275 #3: ffff0000c70b2128 (&dev->master_mutex){+.+.}-{4:4}, at: drm_master_internal_acquire+0x24/0x78 drivers/gpu/drm/drm_auth.c:435 3 locks held by kworker/0:5/4822: #0: ffff0000c002b540 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff0000c002b540 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x734/0x10b8 kernel/workqueue.c:3397 #1: ffff800094307c40 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #1: ffff800094307c40 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_scheduled_works+0x73c/0x10b8 kernel/workqueue.c:3397 #2: ffff800089f9b8c0 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_global_led_trigger_worker+0x30/0xe4 net/rfkill/core.c:185 1 lock held by syz.5.135/5467: #0: ffff0000c802c350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x214/0x3d4 block/bdev.c:1296 1 lock held by syz.5.135/5469: #0: ffff0000c802c350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x214/0x3d4 block/bdev.c:1296 2 locks held by kworker/u8:33/5756: 2 locks held by syz.1.1100/9846: #0: ffff800089f9b8c0 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_fop_write+0x2c4/0x584 net/rfkill/core.c:1306 #1: ffff0000d94f0ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_poweroff net/bluetooth/hci_core.c:857 [inline] #1: ffff0000d94f0ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_rfkill_set_block+0x10c/0x2dc net/bluetooth/hci_core.c:884 2 locks held by syz.8.1106/9896: #0: ffff800088becb00 (console_lock){+.+.}-{0:0}, at: class_console_lock_constructor include/linux/console.h:736 [inline] #0: ffff800088becb00 (console_lock){+.+.}-{0:0}, at: con_font_set drivers/tty/vt/vt.c:4984 [inline] #0: ffff800088becb00 (console_lock){+.+.}-{0:0}, at: con_font_op+0x784/0xc6c drivers/tty/vt/vt.c:5034 #1: ffff0000c7019270 (&helper->lock){+.+.}-{4:4}, at: drm_fb_helper_setcmap+0x120/0x1f20 drivers/gpu/drm/drm_fb_helper.c:861 3 locks held by dhcpcd-run-hook/9904: =============================================