RDX: 0000000000000026 RSI: 0000000020000040 RDI: 0000000000000003 RBP: 00007f4597a391d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffcff0c7b1f R14: 00007f4597a39300 R15: 0000000000022000 ====================================================== WARNING: possible circular locking dependency detected 4.14.288-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.2/29310 is trying to acquire lock: (console_owner){....}, at: [] log_next kernel/printk/printk.c:495 [inline] (console_owner){....}, at: [] console_unlock+0x307/0xf20 kernel/printk/printk.c:2396 but task is already holding lock: (&(&port->lock)->rlock){-.-.}, at: [] pty_write+0xdb/0x1d0 drivers/tty/pty.c:120 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&(&port->lock)->rlock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:160 tty_port_tty_get+0x1d/0x80 drivers/tty/tty_port.c:288 tty_port_default_wakeup+0x11/0x40 drivers/tty/tty_port.c:46 serial8250_tx_chars+0x3fe/0xc70 drivers/tty/serial/8250/8250_port.c:1828 serial8250_handle_irq.part.0+0x28d/0x330 drivers/tty/serial/8250/8250_port.c:1915 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1888 [inline] serial8250_default_handle_irq+0x8a/0x1f0 drivers/tty/serial/8250/8250_port.c:1931 serial8250_interrupt+0xf3/0x210 drivers/tty/serial/8250/8250_core.c:129 __handle_irq_event_percpu+0xee/0x7f0 kernel/irq/handle.c:147 handle_irq_event_percpu kernel/irq/handle.c:187 [inline] handle_irq_event+0xed/0x240 kernel/irq/handle.c:204 handle_edge_irq+0x224/0xc40 kernel/irq/chip.c:770 generic_handle_irq_desc include/linux/irqdesc.h:159 [inline] handle_irq+0x35/0x50 arch/x86/kernel/irq_64.c:87 do_IRQ+0x93/0x1d0 arch/x86/kernel/irq.c:230 ret_from_intr+0x0/0x1e native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0x47/0x370 arch/x86/kernel/process.c:558 cpuidle_idle_call kernel/sched/idle.c:156 [inline] do_idle+0x250/0x3c0 kernel/sched/idle.c:246 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:351 start_kernel+0x743/0x763 init/main.c:712 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 -> #1 (&port_lock_key){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:160 serial8250_console_write+0x7d5/0xa10 drivers/tty/serial/8250/8250_port.c:3271 call_console_drivers kernel/printk/printk.c:1727 [inline] console_unlock+0x99d/0xf20 kernel/printk/printk.c:2409 vprintk_emit+0x224/0x620 kernel/printk/printk.c:1925 vprintk_func+0x58/0x160 kernel/printk/printk_safe.c:409 printk+0x9e/0xbc kernel/printk/printk.c:1998 register_console+0x6f4/0xad0 kernel/printk/printk.c:2728 univ8250_console_init+0x2f/0x3a drivers/tty/serial/8250/8250_core.c:691 console_init+0x46/0x53 kernel/printk/printk.c:2809 start_kernel+0x521/0x763 init/main.c:638 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 -> #0 (console_owner){....}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 console_lock_spinning_enable kernel/printk/printk.c:1590 [inline] console_unlock+0x36f/0xf20 kernel/printk/printk.c:2406 vprintk_emit+0x224/0x620 kernel/printk/printk.c:1925 vprintk_func+0x58/0x160 kernel/printk/printk_safe.c:409 printk+0x9e/0xbc kernel/printk/printk.c:1998 fail_dump lib/fault-inject.c:44 [inline] should_fail.cold+0xdf/0x149 lib/fault-inject.c:149 should_failslab+0xd6/0x130 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc mm/slab.c:3376 [inline] __do_kmalloc mm/slab.c:3718 [inline] __kmalloc+0x6d/0x400 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] tty_buffer_alloc+0xc0/0x270 drivers/tty/tty_buffer.c:169 __tty_buffer_request_room+0x12c/0x290 drivers/tty/tty_buffer.c:268 tty_insert_flip_string_fixed_flag+0x8b/0x210 drivers/tty/tty_buffer.c:313 tty_insert_flip_string include/linux/tty_flip.h:37 [inline] pty_write+0x10d/0x1d0 drivers/tty/pty.c:122 n_tty_write+0x85e/0xda0 drivers/tty/n_tty.c:2356 do_tty_write drivers/tty/tty_io.c:959 [inline] tty_write+0x410/0x740 drivers/tty/tty_io.c:1043 __vfs_write+0xe4/0x630 fs/read_write.c:480 vfs_write+0x17f/0x4d0 fs/read_write.c:544 SYSC_write fs/read_write.c:590 [inline] SyS_write+0xf2/0x210 fs/read_write.c:582 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb other info that might help us debug this: Chain exists of: console_owner --> &port_lock_key --> &(&port->lock)->rlock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(&port->lock)->rlock); lock(&port_lock_key); lock(&(&port->lock)->rlock); lock(console_owner); *** DEADLOCK *** 6 locks held by syz-executor.2/29310: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&tty->atomic_write_lock){+.+.}, at: [] tty_write_lock drivers/tty/tty_io.c:885 [inline] #1: (&tty->atomic_write_lock){+.+.}, at: [] do_tty_write drivers/tty/tty_io.c:908 [inline] #1: (&tty->atomic_write_lock){+.+.}, at: [] tty_write+0x22d/0x740 drivers/tty/tty_io.c:1043 #2: (&tty->termios_rwsem){++++}, at: [] n_tty_write+0x18a/0xda0 drivers/tty/n_tty.c:2316 #3: (&ldata->output_lock){+.+.}, at: [] n_tty_write+0x82b/0xda0 drivers/tty/n_tty.c:2355 #4: (&(&port->lock)->rlock){-.-.}, at: [] pty_write+0xdb/0x1d0 drivers/tty/pty.c:120 #5: (console_lock){+.+.}, at: [] vprintk_func+0x58/0x160 kernel/printk/printk_safe.c:409 stack backtrace: CPU: 1 PID: 29310 Comm: syz-executor.2 Not tainted 4.14.288-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 console_lock_spinning_enable kernel/printk/printk.c:1590 [inline] console_unlock+0x36f/0xf20 kernel/printk/printk.c:2406 vprintk_emit+0x224/0x620 kernel/printk/printk.c:1925 vprintk_func+0x58/0x160 kernel/printk/printk_safe.c:409 printk+0x9e/0xbc kernel/printk/printk.c:1998 fail_dump lib/fault-inject.c:44 [inline] should_fail.cold+0xdf/0x149 lib/fault-inject.c:149 should_failslab+0xd6/0x130 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc mm/slab.c:3376 [inline] __do_kmalloc mm/slab.c:3718 [inline] __kmalloc+0x6d/0x400 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] tty_buffer_alloc+0xc0/0x270 drivers/tty/tty_buffer.c:169 __tty_buffer_request_room+0x12c/0x290 drivers/tty/tty_buffer.c:268 tty_insert_flip_string_fixed_flag+0x8b/0x210 drivers/tty/tty_buffer.c:313 tty_insert_flip_string include/linux/tty_flip.h:37 [inline] pty_write+0x10d/0x1d0 drivers/tty/pty.c:122 n_tty_write+0x85e/0xda0 drivers/tty/n_tty.c:2356 do_tty_write drivers/tty/tty_io.c:959 [inline] tty_write+0x410/0x740 drivers/tty/tty_io.c:1043 __vfs_write+0xe4/0x630 fs/read_write.c:480 vfs_write+0x17f/0x4d0 fs/read_write.c:544 SYSC_write fs/read_write.c:590 [inline] SyS_write+0xf2/0x210 fs/read_write.c:582 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f45990c4109 RSP: 002b:00007f4597a39168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f45991d6f60 RCX: 00007f45990c4109 RDX: 0000000000000026 RSI: 0000000020000040 RDI: 0000000000000003 RBP: 00007f4597a391d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffcff0c7b1f R14: 00007f4597a39300 R15: 0000000000022000 FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 29314 Comm: syz-executor.1 Not tainted 4.14.288-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0x10a/0x149 lib/fault-inject.c:149 should_fail_alloc_page mm/page_alloc.c:2898 [inline] prepare_alloc_pages mm/page_alloc.c:4131 [inline] __alloc_pages_nodemask+0x22c/0x2720 mm/page_alloc.c:4179 FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 0 alloc_pages_current+0x155/0x260 mm/mempolicy.c:2107 alloc_pages include/linux/gfp.h:520 [inline] __get_free_pages+0xb/0x40 mm/page_alloc.c:4233 tlb_next_batch mm/memory.c:217 [inline] __tlb_remove_page_size+0x272/0x440 mm/memory.c:329 __tlb_remove_page include/asm-generic/tlb.h:152 [inline] zap_pte_range mm/memory.c:1378 [inline] zap_pmd_range mm/memory.c:1479 [inline] zap_pud_range mm/memory.c:1508 [inline] zap_p4d_range mm/memory.c:1529 [inline] unmap_page_range+0xf94/0x1d90 mm/memory.c:1550 unmap_single_vma+0x147/0x2b0 mm/memory.c:1595 unmap_vmas+0x9d/0x160 mm/memory.c:1625 exit_mmap+0x270/0x4d0 mm/mmap.c:3058 __mmput kernel/fork.c:931 [inline] mmput kernel/fork.c:952 [inline] mmput+0xfa/0x420 kernel/fork.c:947 exit_mm kernel/exit.c:548 [inline] do_exit+0x984/0x2850 kernel/exit.c:855 do_group_exit+0x100/0x2e0 kernel/exit.c:965 get_signal+0x38d/0x1ca0 kernel/signal.c:2412 do_signal+0x7c/0x1550 arch/x86/kernel/signal.c:792 exit_to_usermode_loop+0x160/0x200 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fd433699109 RSP: 002b:00007fd43200e168 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: 0000000000000001 RBX: 00007fd4337abf60 RCX: 00007fd433699109 RDX: 0000000000002020 RSI: 0000000020002980 RDI: 0000000000000003 RBP: 00007fd43200e1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffdd996e58f R14: 00007fd43200e300 R15: 0000000000022000 CPU: 1 PID: 29265 Comm: syz-executor.5 Not tainted 4.14.288-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0x10a/0x149 lib/fault-inject.c:149 should_fail_alloc_page mm/page_alloc.c:2898 [inline] prepare_alloc_pages mm/page_alloc.c:4131 [inline] __alloc_pages_nodemask+0x22c/0x2720 mm/page_alloc.c:4179 alloc_pages_current+0x155/0x260 mm/mempolicy.c:2107 alloc_pages include/linux/gfp.h:520 [inline] __get_free_pages+0xb/0x40 mm/page_alloc.c:4233 tlb_next_batch mm/memory.c:217 [inline] __tlb_remove_page_size+0x272/0x440 mm/memory.c:329 __tlb_remove_page include/asm-generic/tlb.h:152 [inline] zap_pte_range mm/memory.c:1378 [inline] zap_pmd_range mm/memory.c:1479 [inline] zap_pud_range mm/memory.c:1508 [inline] zap_p4d_range mm/memory.c:1529 [inline] unmap_page_range+0xf94/0x1d90 mm/memory.c:1550 unmap_single_vma+0x147/0x2b0 mm/memory.c:1595 unmap_vmas+0x9d/0x160 mm/memory.c:1625 exit_mmap+0x270/0x4d0 mm/mmap.c:3058 __mmput kernel/fork.c:931 [inline] mmput kernel/fork.c:952 [inline] mmput+0xfa/0x420 kernel/fork.c:947 exit_mm kernel/exit.c:548 [inline] do_exit+0x984/0x2850 kernel/exit.c:855 do_group_exit+0x100/0x2e0 kernel/exit.c:965 get_signal+0x38d/0x1ca0 kernel/signal.c:2412 do_signal+0x7c/0x1550 arch/x86/kernel/signal.c:792 exit_to_usermode_loop+0x160/0x200 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f2d10fc8109 RSP: 002b:00007f2d0f93d168 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: 0000000000000001 RBX: 00007f2d110daf60 RCX: 00007f2d10fc8109 RDX: 0000000000002020 RSI: 0000000020002980 RDI: 0000000000000003 RBP: 00007f2d0f93d1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffc5b34d8bf R14: 00007f2d0f93d300 R15: 0000000000022000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 29330 Comm: syz-executor.0 Not tainted 4.14.288-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0x10a/0x149 lib/fault-inject.c:149 should_failslab+0xd6/0x130 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc mm/slab.c:3376 [inline] __do_kmalloc mm/slab.c:3718 [inline] __kmalloc+0x2c1/0x400 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] do_tty_write drivers/tty/tty_io.c:941 [inline] tty_write+0x4e0/0x740 drivers/tty/tty_io.c:1043 __vfs_write+0xe4/0x630 fs/read_write.c:480 vfs_write+0x17f/0x4d0 fs/read_write.c:544 SYSC_write fs/read_write.c:590 [inline] SyS_write+0xf2/0x210 fs/read_write.c:582 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f35bbb51109 RSP: 002b:00007f35ba4c6168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f35bbc63f60 RCX: 00007f35bbb51109 RDX: 0000000000000026 RSI: 0000000020000040 RDI: 0000000000000003 RBP: 00007f35ba4c61d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffe8b82fd5f R14: 00007f35ba4c6300 R15: 0000000000022000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 29362 Comm: syz-executor.0 Not tainted 4.14.288-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0x10a/0x149 lib/fault-inject.c:149 should_failslab+0xd6/0x130 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc mm/slab.c:3376 [inline] __do_kmalloc mm/slab.c:3718 [inline] __kmalloc+0x6d/0x400 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] tty_buffer_alloc+0xc0/0x270 drivers/tty/tty_buffer.c:169 __tty_buffer_request_room+0x12c/0x290 drivers/tty/tty_buffer.c:268 tty_insert_flip_string_fixed_flag+0x8b/0x210 drivers/tty/tty_buffer.c:313 tty_insert_flip_string include/linux/tty_flip.h:37 [inline] pty_write+0x10d/0x1d0 drivers/tty/pty.c:122 n_tty_write+0x85e/0xda0 drivers/tty/n_tty.c:2356 do_tty_write drivers/tty/tty_io.c:959 [inline] tty_write+0x410/0x740 drivers/tty/tty_io.c:1043 __vfs_write+0xe4/0x630 fs/read_write.c:480 vfs_write+0x17f/0x4d0 fs/read_write.c:544 SYSC_write fs/read_write.c:590 [inline] SyS_write+0xf2/0x210 fs/read_write.c:582 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f35bbb51109 RSP: 002b:00007f35ba4c6168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f35bbc63f60 RCX: 00007f35bbb51109 RDX: 0000000000000026 RSI: 0000000020000040 RDI: 0000000000000003 RBP: 00007f35ba4c61d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffe8b82fd5f R14: 00007f35ba4c6300 R15: 0000000000022000