BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 3606, name: syz-executor269 preempt_count: 101, expected: 0 RCU nest depth: 0, expected: 0 3 locks held by syz-executor269/3606: #0: ffff8880250eb098 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:290 [inline] #0: ffff8880250eb098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:353 [inline] #0: ffff8880250eb098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline] #0: ffff8880250eb098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0x79/0x2a0 drivers/tty/tty_ldisc.c:775 #1: ffff888017ac60b0 (&gsm->mutex){+.+.}-{3:3}, at: gsm_cleanup_mux+0xf5/0x800 drivers/tty/n_gsm.c:2446 #2: ffffc900001f0d70 ((&dlci->t1)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:31 [inline] #2: ffffc900001f0d70 ((&dlci->t1)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 kernel/time/timer.c:1464 Preemption disabled at: [<0000000000000000>] 0x0 CPU: 1 PID: 3606 Comm: syz-executor269 Not tainted 6.0.0-rc6-syzkaller-00309-g1a61b828566f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 __might_resched.cold+0x222/0x26b kernel/sched/core.c:9892 __mutex_lock_common kernel/locking/mutex.c:580 [inline] __mutex_lock+0x9f/0x1350 kernel/locking/mutex.c:747 gsm_send.isra.0+0x3b5/0x7a0 drivers/tty/n_gsm.c:704 gsm_command drivers/tty/n_gsm.c:768 [inline] gsm_dlci_begin_close+0x12e/0x210 drivers/tty/n_gsm.c:1892 gsm_dlci_t1+0x186/0x450 drivers/tty/n_gsm.c:1816 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers.part.0+0x674/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803 __do_softirq+0x1d3/0x9c6 kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194 Code: 74 24 10 e8 fa 1d dc f7 48 89 ef e8 82 9f dc f7 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 33 61 cf f7 65 8b 05 4c 17 7f 76 85 c0 74 0a 5b 5d c3 e8 50 28 RSP: 0018:ffffc90003aef950 EFLAGS: 00000206 RAX: 0000000000000006 RBX: 0000000000000200 RCX: 1ffffffff21265a6 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffff888011bee148 R08: 0000000000000001 R09: ffffffff908e5a0f R10: 0000000000000001 R11: 0000000000000000 R12: ffff88801bc424c0 R13: ffffc90003aef9e8 R14: ffff888011bee148 R15: 0000000000000000 spin_unlock_irqrestore include/linux/spinlock.h:404 [inline] klist_next+0x288/0x510 lib/klist.c:401 class_dev_iter_next drivers/base/class.c:311 [inline] class_find_device+0x174/0x2a0 drivers/base/class.c:415 class_find_device_by_devt include/linux/device/class.h:167 [inline] device_destroy+0x79/0xd0 drivers/base/core.c:4299 tty_unregister_device+0x7e/0x1b0 drivers/tty/tty_io.c:3299 gsm_unregister_devices drivers/tty/n_gsm.c:564 [inline] gsm_cleanup_mux+0x5c1/0x800 drivers/tty/n_gsm.c:2465 gsmld_close+0x41/0x210 drivers/tty/n_gsm.c:2907 tty_ldisc_close+0x110/0x190 drivers/tty/tty_ldisc.c:456 tty_ldisc_kill+0x94/0x150 drivers/tty/tty_ldisc.c:608 tty_ldisc_release+0x1ef/0x2a0 drivers/tty/tty_ldisc.c:776 tty_release_struct+0x20/0xe0 drivers/tty/tty_io.c:1694 tty_release+0xc70/0x1200 drivers/tty/tty_io.c:1865 __fput+0x277/0x9d0 fs/file_table.c:320 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xad5/0x29b0 kernel/exit.c:795 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 __do_sys_exit_group kernel/exit.c:936 [inline] __se_sys_exit_group kernel/exit.c:934 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:934 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f642cb30f69 Code: Unable to access opcode bytes at RIP 0x7f642cb30f3f. RSP: 002b:00007ffed5a9f4c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f642cba5330 RCX: 00007f642cb30f69 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000000000 R10: 000000000000000e R11: 0000000000000246 R12: 00007f642cba5330 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001 ============================= [ BUG: Invalid wait context ] 6.0.0-rc6-syzkaller-00309-g1a61b828566f #0 Tainted: G W ----------------------------- syz-executor269/3606 is trying to lock: ffff888017ac6430 (&gsm->tx_mutex){+.+.}-{3:3}, at: gsm_send.isra.0+0x3b5/0x7a0 drivers/tty/n_gsm.c:704 other info that might help us debug this: context-{2:2} 3 locks held by syz-executor269/3606: #0: ffff8880250eb098 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:290 [inline] #0: ffff8880250eb098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:353 [inline] #0: ffff8880250eb098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline] #0: ffff8880250eb098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0x79/0x2a0 drivers/tty/tty_ldisc.c:775 #1: ffff888017ac60b0 (&gsm->mutex){+.+.}-{3:3}, at: gsm_cleanup_mux+0xf5/0x800 drivers/tty/n_gsm.c:2446 #2: ffffc900001f0d70 ((&dlci->t1)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:31 [inline] #2: ffffc900001f0d70 ((&dlci->t1)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 kernel/time/timer.c:1464 stack backtrace: CPU: 1 PID: 3606 Comm: syz-executor269 Tainted: G W 6.0.0-rc6-syzkaller-00309-g1a61b828566f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_lock_invalid_wait_context kernel/locking/lockdep.c:4705 [inline] check_wait_context kernel/locking/lockdep.c:4766 [inline] __lock_acquire.cold+0x322/0x3a7 kernel/locking/lockdep.c:5003 lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12f/0x1350 kernel/locking/mutex.c:747 gsm_send.isra.0+0x3b5/0x7a0 drivers/tty/n_gsm.c:704 gsm_command drivers/tty/n_gsm.c:768 [inline] gsm_dlci_begin_close+0x12e/0x210 drivers/tty/n_gsm.c:1892 gsm_dlci_t1+0x186/0x450 drivers/tty/n_gsm.c:1816 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers.part.0+0x674/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803 __do_softirq+0x1d3/0x9c6 kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194 Code: 74 24 10 e8 fa 1d dc f7 48 89 ef e8 82 9f dc f7 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 33 61 cf f7 65 8b 05 4c 17 7f 76 85 c0 74 0a 5b 5d c3 e8 50 28 RSP: 0018:ffffc90003aef950 EFLAGS: 00000206 RAX: 0000000000000006 RBX: 0000000000000200 RCX: 1ffffffff21265a6 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffff888011bee148 R08: 0000000000000001 R09: ffffffff908e5a0f R10: 0000000000000001 R11: 0000000000000000 R12: ffff88801bc424c0 R13: ffffc90003aef9e8 R14: ffff888011bee148 R15: 0000000000000000 spin_unlock_irqrestore include/linux/spinlock.h:404 [inline] klist_next+0x288/0x510 lib/klist.c:401 class_dev_iter_next drivers/base/class.c:311 [inline] class_find_device+0x174/0x2a0 drivers/base/class.c:415 class_find_device_by_devt include/linux/device/class.h:167 [inline] device_destroy+0x79/0xd0 drivers/base/core.c:4299 tty_unregister_device+0x7e/0x1b0 drivers/tty/tty_io.c:3299 gsm_unregister_devices drivers/tty/n_gsm.c:564 [inline] gsm_cleanup_mux+0x5c1/0x800 drivers/tty/n_gsm.c:2465 gsmld_close+0x41/0x210 drivers/tty/n_gsm.c:2907 tty_ldisc_close+0x110/0x190 drivers/tty/tty_ldisc.c:456 tty_ldisc_kill+0x94/0x150 drivers/tty/tty_ldisc.c:608 tty_ldisc_release+0x1ef/0x2a0 drivers/tty/tty_ldisc.c:776 tty_release_struct+0x20/0xe0 drivers/tty/tty_io.c:1694 tty_release+0xc70/0x1200 drivers/tty/tty_io.c:1865 __fput+0x277/0x9d0 fs/file_table.c:320 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xad5/0x29b0 kernel/exit.c:795 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 __do_sys_exit_group kernel/exit.c:936 [inline] __se_sys_exit_group kernel/exit.c:934 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:934 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f642cb30f69 Code: Unable to access opcode bytes at RIP 0x7f642cb30f3f. RSP: 002b:00007ffed5a9f4c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f642cba5330 RCX: 00007f642cb30f69 RDX: 000000 ---------------- Code disassembly (best guess): 0: 74 24 je 0x26 2: 10 e8 adc %ch,%al 4: fa cli 5: 1d dc f7 48 89 sbb $0x8948f7dc,%eax a: ef out %eax,(%dx) b: e8 82 9f dc f7 callq 0xf7dc9f92 10: 81 e3 00 02 00 00 and $0x200,%ebx 16: 75 25 jne 0x3d 18: 9c pushfq 19: 58 pop %rax 1a: f6 c4 02 test $0x2,%ah 1d: 75 2d jne 0x4c 1f: 48 85 db test %rbx,%rbx 22: 74 01 je 0x25 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 33 61 cf f7 callq 0xf7cf6162 <-- trapping instruction 2f: 65 8b 05 4c 17 7f 76 mov %gs:0x767f174c(%rip),%eax # 0x767f1782 36: 85 c0 test %eax,%eax 38: 74 0a je 0x44 3a: 5b pop %rbx 3b: 5d pop %rbp 3c: c3 retq 3d: e8 .byte 0xe8 3e: 50 push %rax 3f: 28 .byte 0x28