INFO: task syz.6.648:6732 blocked for more than 430 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.648 state:D stack:0 pid:6732 tgid:6731 ppid:6277 task_flags:0x40044c flags:0x00000010 Call trace: __switch_to+0x584/0xb00 arch/arm64/kernel/process.c:742 (T) context_switch kernel/sched/core.c:5256 [inline] __schedule+0x200c/0x3428 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xac/0x27c kernel/sched/core.c:6960 schedule_timeout+0x68/0x1ec kernel/time/sleep_timeout.c:75 do_wait_for_common+0x28c/0x440 kernel/sched/completion.c:100 __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x44/0x5c kernel/sched/completion.c:153 __synchronize_srcu+0x2a4/0x320 kernel/rcu/srcutree.c:1518 synchronize_srcu+0x3d0/0x4f8 kernel/rcu/srcutree.c:-1 mn_hlist_release mm/mmu_notifier.c:347 [inline] __mmu_notifier_release+0x424/0x614 mm/mmu_notifier.c:359 mmu_notifier_release include/linux/mmu_notifier.h:402 [inline] exit_mmap+0xbc/0xb8c mm/mmap.c:1260 __mmput+0x10c/0x528 kernel/fork.c:1173 mmput+0x70/0xa8 kernel/fork.c:1196 exit_mm+0x158/0x248 kernel/exit.c:581 do_exit+0x790/0x2378 kernel/exit.c:959 do_group_exit+0x1d4/0x2ac kernel/exit.c:1112 get_signal+0x1440/0x154c kernel/signal.c:3034 arch_do_signal_or_restart+0x23c/0x4bac arch/arm64/kernel/signal.c:1619 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x88/0x188 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] exit_to_user_mode_prepare_legacy include/linux/irq-entry-common.h:242 [inline] arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:81 [inline] el0_svc+0x17c/0x238 arch/arm64/kernel/entry-common.c:725 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffff800087a86d08 (rcu_read_lock){....}-{1:3}, at: __ll_sc_atomic64_fetch_or arch/arm64/include/asm/atomic_ll_sc.h:-1 [inline] #0: ffff800087a86d08 (rcu_read_lock){....}-{1:3}, at: arch_atomic64_fetch_or arch/arm64/include/asm/atomic.h:86 [inline] #0: ffff800087a86d08 (rcu_read_lock){....}-{1:3}, at: raw_atomic64_fetch_or include/linux/atomic/atomic-arch-fallback.h:3816 [inline] #0: ffff800087a86d08 (rcu_read_lock){....}-{1:3}, at: raw_atomic_long_fetch_or include/linux/atomic/atomic-long.h:1090 [inline] #0: ffff800087a86d08 (rcu_read_lock){....}-{1:3}, at: arch_test_and_set_bit include/asm-generic/bitops/atomic.h:42 [inline] #0: ffff800087a86d08 (rcu_read_lock){....}-{1:3}, at: test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:72 [inline] #0: ffff800087a86d08 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x0/0x44 kernel/sched/sched.h:3748 2 locks held by getty/3200: #0: 97f000001231e8a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340 #1: eeff80008c80b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x308/0x1234 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/3333: 3 locks held by kworker/u4:1/5265: 3 locks held by kworker/u4:2/5681: 3 locks held by kworker/u4:4/5711: 3 locks held by kworker/u4:11/5720: 3 locks held by kworker/u4:13/5949: 4 locks held by kworker/0:3/6280: 2 locks held by kworker/u4:6/6405: #0: 44f000000cc26948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x7c8/0x1a10 kernel/workqueue.c:3231 #1: ffff80008eb27c88 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x854/0x1a10 kernel/workqueue.c:3231 2 locks held by kworker/u4:15/6514: #0: 44f000000cc26948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x7c8/0x1a10 kernel/workqueue.c:3231 #1: ffff80008c7e7c88 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x854/0x1a10 kernel/workqueue.c:3231 2 locks held by kworker/0:0/6515: 3 locks held by kworker/u4:0/6692: 2 locks held by syz.7.647/6726: 3 locks held by kworker/u4:8/6750: 2 locks held by kworker/u4:10/6775: 3 locks held by kworker/u4:16/6844: 4 locks held by modprobe/6874: 1 lock held by modprobe/6875: =============================================