RBP: 00007f982a3031d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffeee7e3d7f R14: 00007f982a303300 R15: 0000000000022000 ====================================================== WARNING: possible circular locking dependency detected 5.10.240 #1 Not tainted ------------------------------------------------------ syz-executor.3/10909 is trying to acquire lock: ffffffff84f0dbe0 (console_owner){-.-.}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:1833 [inline] ffffffff84f0dbe0 (console_owner){-.-.}-{0:0}, at: vprintk_emit+0x2ca/0x4e0 kernel/printk/printk.c:2059 but task is already holding lock: ffff88801c1ce958 (&port->lock){-.-.}-{2:2}, at: tty_insert_flip_string_and_push_buffer+0x2b/0x160 drivers/tty/tty_buffer.c:575 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&port->lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x36/0x60 kernel/locking/spinlock.c:159 tty_port_tty_get+0x1f/0x100 drivers/tty/tty_port.c:289 tty_port_default_wakeup+0x11/0x40 drivers/tty/tty_port.c:48 serial8250_tx_chars+0x51f/0xb00 drivers/tty/serial/8250/8250_port.c:1826 serial8250_handle_irq+0x4e4/0x660 drivers/tty/serial/8250/8250_port.c:1922 serial8250_default_handle_irq+0x96/0x210 drivers/tty/serial/8250/8250_port.c:1938 serial8250_interrupt+0xf4/0x1b0 drivers/tty/serial/8250/8250_core.c:127 __handle_irq_event_percpu+0x2ef/0x6d0 kernel/irq/handle.c:156 handle_irq_event_percpu kernel/irq/handle.c:196 [inline] handle_irq_event+0xff/0x280 kernel/irq/handle.c:213 handle_edge_irq+0x249/0xd00 kernel/irq/chip.c:819 asm_call_irq_on_stack+0x12/0x20 __run_irq_on_irqstack arch/x86/include/asm/irq_stack.h:48 [inline] run_irq_on_irqstack_cond arch/x86/include/asm/irq_stack.h:101 [inline] handle_irq arch/x86/kernel/irq.c:232 [inline] __common_interrupt arch/x86/kernel/irq.c:251 [inline] common_interrupt+0xdd/0x1a0 arch/x86/kernel/irq.c:241 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:626 native_restore_fl arch/x86/include/asm/irqflags.h:41 [inline] arch_local_irq_restore arch/x86/include/asm/irqflags.h:84 [inline] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0x25/0x40 kernel/locking/spinlock.c:191 spin_unlock_irqrestore include/linux/spinlock.h:409 [inline] uart_write+0x304/0x580 drivers/tty/serial/serial_core.c:616 do_output_char+0x5e8/0x870 drivers/tty/n_tty.c:443 process_output drivers/tty/n_tty.c:510 [inline] n_tty_write+0x4c9/0xfe0 drivers/tty/n_tty.c:2396 do_tty_write drivers/tty/tty_io.c:1029 [inline] file_tty_write.constprop.0+0x529/0x910 drivers/tty/tty_io.c:1119 redirected_tty_write+0xa5/0xd0 drivers/tty/tty_io.c:1126 call_write_iter include/linux/fs.h:2039 [inline] do_iter_readv_writev+0x476/0x750 fs/read_write.c:740 do_iter_write+0x191/0x700 fs/read_write.c:866 vfs_writev+0x1ae/0x620 fs/read_write.c:939 do_writev+0x139/0x300 fs/read_write.c:982 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xd1 -> #1 (&port_lock_key){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x36/0x60 kernel/locking/spinlock.c:159 serial8250_console_write+0x9f5/0xc60 drivers/tty/serial/8250/8250_port.c:3334 call_console_drivers kernel/printk/printk.c:1917 [inline] console_unlock+0x82a/0xb40 kernel/printk/printk.c:2538 register_console kernel/printk/printk.c:2902 [inline] register_console+0x40c/0x850 kernel/printk/printk.c:2802 univ8250_console_init+0x3a/0x4a drivers/tty/serial/8250/8250_core.c:700 console_init+0x24c/0x356 kernel/printk/printk.c:3012 start_kernel+0x2e6/0x489 init/main.c:981 secondary_startup_64_no_verify+0xbe/0xcb -> #0 (console_owner){-.-.}-{0:0}: check_prev_add kernel/locking/lockdep.c:2988 [inline] check_prevs_add kernel/locking/lockdep.c:3113 [inline] validate_chain kernel/locking/lockdep.c:3729 [inline] __lock_acquire+0x29e7/0x5b00 kernel/locking/lockdep.c:4955 lock_acquire kernel/locking/lockdep.c:5566 [inline] lock_acquire+0x197/0x470 kernel/locking/lockdep.c:5531 console_trylock_spinning kernel/printk/printk.c:1854 [inline] vprintk_emit+0x307/0x4e0 kernel/printk/printk.c:2059 vprintk_func+0x8b/0x140 kernel/printk/printk_safe.c:401 printk+0xba/0xf1 kernel/printk/printk.c:2108 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x47a/0x5a0 lib/fault-inject.c:146 should_failslab+0x5/0x20 mm/slab_common.c:1200 slab_pre_alloc_hook mm/slab.h:515 [inline] slab_alloc_node mm/slub.c:2821 [inline] slab_alloc mm/slub.c:2904 [inline] __kmalloc+0x72/0x390 mm/slub.c:3967 kmalloc include/linux/slab.h:557 [inline] tty_buffer_alloc+0x243/0x2b0 drivers/tty/tty_buffer.c:175 __tty_buffer_request_room+0x156/0x2a0 drivers/tty/tty_buffer.c:274 tty_insert_flip_string_fixed_flag+0x91/0x250 drivers/tty/tty_buffer.c:319 tty_insert_flip_string include/linux/tty_flip.h:36 [inline] tty_insert_flip_string_and_push_buffer+0x3e/0x160 drivers/tty/tty_buffer.c:576 pty_write+0xe6/0x110 drivers/tty/pty.c:119 tty_send_xchar+0x29b/0x3c0 drivers/tty/tty_io.c:1176 n_tty_ioctl_helper+0x191/0x3a0 drivers/tty/tty_ioctl.c:892 n_tty_ioctl+0x56/0x370 drivers/tty/n_tty.c:2517 tty_ioctl+0x912/0x18b0 drivers/tty/tty_io.c:2757 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xd1 other info that might help us debug this: Chain exists of: console_owner --> &port_lock_key --> &port->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&port->lock); lock(&port_lock_key); lock(&port->lock); lock(console_owner); *** DEADLOCK *** 4 locks held by syz-executor.3/10909: #0: ffff888046430098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x90 drivers/tty/tty_ldisc.c:267 #1: ffff888046430130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: tty_write_lock drivers/tty/tty_io.c:953 [inline] #1: ffff888046430130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: tty_send_xchar+0x1e2/0x3c0 drivers/tty/tty_io.c:1170 #2: ffff8880464302e8 (&tty->termios_rwsem){++++}-{3:3}, at: tty_send_xchar+0x22f/0x3c0 drivers/tty/tty_io.c:1173 #3: ffff88801c1ce958 (&port->lock){-.-.}-{2:2}, at: tty_insert_flip_string_and_push_buffer+0x2b/0x160 drivers/tty/tty_buffer.c:575 stack backtrace: CPU: 1 PID: 10909 Comm: syz-executor.3 Not tainted 5.10.240 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:118 check_noncircular+0x263/0x2e0 kernel/locking/lockdep.c:2123 check_prev_add kernel/locking/lockdep.c:2988 [inline] check_prevs_add kernel/locking/lockdep.c:3113 [inline] validate_chain kernel/locking/lockdep.c:3729 [inline] __lock_acquire+0x29e7/0x5b00 kernel/locking/lockdep.c:4955 lock_acquire kernel/locking/lockdep.c:5566 [inline] lock_acquire+0x197/0x470 kernel/locking/lockdep.c:5531 console_trylock_spinning kernel/printk/printk.c:1854 [inline] vprintk_emit+0x307/0x4e0 kernel/printk/printk.c:2059 vprintk_func+0x8b/0x140 kernel/printk/printk_safe.c:401 printk+0xba/0xf1 kernel/printk/printk.c:2108 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x47a/0x5a0 lib/fault-inject.c:146 should_failslab+0x5/0x20 mm/slab_common.c:1200 slab_pre_alloc_hook mm/slab.h:515 [inline] slab_alloc_node mm/slub.c:2821 [inline] slab_alloc mm/slub.c:2904 [inline] __kmalloc+0x72/0x390 mm/slub.c:3967 kmalloc include/linux/slab.h:557 [inline] tty_buffer_alloc+0x243/0x2b0 drivers/tty/tty_buffer.c:175 __tty_buffer_request_room+0x156/0x2a0 drivers/tty/tty_buffer.c:274 tty_insert_flip_string_fixed_flag+0x91/0x250 drivers/tty/tty_buffer.c:319 tty_insert_flip_string include/linux/tty_flip.h:36 [inline] tty_insert_flip_string_and_push_buffer+0x3e/0x160 drivers/tty/tty_buffer.c:576 pty_write+0xe6/0x110 drivers/tty/pty.c:119 tty_send_xchar+0x29b/0x3c0 drivers/tty/tty_io.c:1176 n_tty_ioctl_helper+0x191/0x3a0 drivers/tty/tty_ioctl.c:892 n_tty_ioctl+0x56/0x370 drivers/tty/n_tty.c:2517 tty_ioctl+0x912/0x18b0 drivers/tty/tty_io.c:2757 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xd1 RIP: 0033:0x7f982cd8db19 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f982a303188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f982cea0f60 RCX: 00007f982cd8db19 RDX: 0000000000000003 RSI: 000000000000540a RDI: 0000000000000003 RBP: 00007f982a3031d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffeee7e3d7f R14: 00007f982a303300 R15: 0000000000022000 loop5: detected capacity change from 0 to 16896 loop6: detected capacity change from 0 to 16896 loop2: detected capacity change from 0 to 16896 loop4: detected capacity change from 0 to 16896 EXT4-fs (loop6): VFS: Can't find ext4 filesystem EXT4-fs (loop5): VFS: Can't find ext4 filesystem EXT4-fs (loop4): VFS: Can't find ext4 filesystem EXT4-fs (loop2): VFS: Can't find ext4 filesystem FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 10938 Comm: syz-executor.3 Not tainted 5.10.240 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:118 fail_dump lib/fault-inject.c:52 [inline] should_fail.cold+0x5/0xa lib/fault-inject.c:146 should_failslab+0x5/0x20 mm/slab_common.c:1200 slab_pre_alloc_hook mm/slab.h:515 [inline] slab_alloc_node mm/slub.c:2821 [inline] slab_alloc mm/slub.c:2904 [inline] kmem_cache_alloc+0x5b/0x310 mm/slub.c:2909 mem_pool_alloc mm/kmemleak.c:423 [inline] create_object.isra.0+0x3a/0xa20 mm/kmemleak.c:578 kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline] slab_post_alloc_hook mm/slab.h:534 [inline] slab_alloc_node mm/slub.c:2896 [inline] slab_alloc mm/slub.c:2904 [inline] __kmalloc+0x16e/0x390 mm/slub.c:3967 kmalloc include/linux/slab.h:557 [inline] tty_buffer_alloc+0x243/0x2b0 drivers/tty/tty_buffer.c:175 __tty_buffer_request_room+0x156/0x2a0 drivers/tty/tty_buffer.c:274 tty_insert_flip_string_fixed_flag+0x91/0x250 drivers/tty/tty_buffer.c:319 tty_insert_flip_string include/linux/tty_flip.h:36 [inline] tty_insert_flip_string_and_push_buffer+0x3e/0x160 drivers/tty/tty_buffer.c:576 pty_write+0xe6/0x110 drivers/tty/pty.c:119 tty_send_xchar+0x29b/0x3c0 drivers/tty/tty_io.c:1176 n_tty_ioctl_helper+0x191/0x3a0 drivers/tty/tty_ioctl.c:892 n_tty_ioctl+0x56/0x370 drivers/tty/n_tty.c:2517 tty_ioctl+0x912/0x18b0 drivers/tty/tty_io.c:2757 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xd1 RIP: 0033:0x7f982cd8db19 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f982a303188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f982cea0f60 RCX: 00007f982cd8db19 RDX: 0000000000000003 RSI: 000000000000540a RDI: 0000000000000003 RBP: 00007f982a3031d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffeee7e3d7f R14: 00007f982a303300 R15: 0000000000022000 FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 10937 Comm: syz-executor.7 Not tainted 5.10.240 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:118 fail_dump lib/fault-inject.c:52 [inline] should_fail.cold+0x5/0xa lib/fault-inject.c:146 prepare_alloc_pages mm/page_alloc.c:4950 [inline] __alloc_pages_nodemask+0x182/0x600 mm/page_alloc.c:4992 alloc_pages_vma+0xbb/0x410 mm/mempolicy.c:2229 alloc_zeroed_user_highpage_movable include/linux/highmem.h:277 [inline] do_anonymous_page mm/memory.c:3635 [inline] handle_pte_fault mm/memory.c:4495 [inline] __handle_mm_fault mm/memory.c:4632 [inline] handle_mm_fault+0x152f/0x3500 mm/memory.c:4730 do_user_addr_fault+0x56e/0xc60 arch/x86/mm/fault.c:1345 handle_page_fault arch/x86/mm/fault.c:1402 [inline] exc_page_fault+0xa2/0x1a0 arch/x86/mm/fault.c:1458 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:571 RIP: 0010:copy_user_generic_string+0x2c/0x40 arch/x86/lib/copy_user_64.S:169 Code: cb 83 fa 08 72 27 89 f9 83 e1 07 74 15 83 e9 08 f7 d9 29 ca 8a 06 88 07 48 ff c6 48 ff c7 ff c9 75 f2 89 d1 c1 e9 03 83 e2 07 48 a5 89 d1 f3 a4 31 c0 0f 01 ca e9 73 64 1d 02 0f 1f 00 0f 01 RSP: 0018:ffff888047abfb08 EFLAGS: 00050246 RAX: 0000000000000001 RBX: 0000000000001000 RCX: 00000000000001c0 RDX: 0000000000000000 RSI: ffff888046d3d200 RDI: 0000000020002000 RBP: 0000000020001e00 R08: 0000000000000000 R09: ffff888046d3dfff R10: ffffed1008da7bff R11: 0000000000000001 R12: 0000000020002e00 R13: ffff888046d3d000 R14: 00007ffffffff000 R15: 0000000000000000 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline] _copy_to_user lib/usercopy.c:40 [inline] _copy_to_user+0x13d/0x180 lib/usercopy.c:33 copy_to_user include/linux/uaccess.h:200 [inline] vcs_read+0x67d/0xbc0 drivers/tty/vt/vc_screen.c:456 do_loop_readv_writev fs/read_write.c:761 [inline] do_loop_readv_writev fs/read_write.c:748 [inline] do_iter_read+0x4fa/0x760 fs/read_write.c:803 vfs_readv+0xe5/0x160 fs/read_write.c:921 do_readv+0x139/0x300 fs/read_write.c:958 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xd1 RIP: 0033:0x7f7168f7db19 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f71664f3188 EFLAGS: 00000246 ORIG_RAX: 0000000000000013 RAX: ffffffffffffffda RBX: 00007f7169090f60 RCX: 00007f7168f7db19 RDX: 0000000000000001 RSI: 0000000020000100 RDI: 0000000000000003 RBP: 00007f71664f31d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffc079c0a3f R14: 00007f71664f3300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: cb lret 1: 83 fa 08 cmp $0x8,%edx 4: 72 27 jb 0x2d 6: 89 f9 mov %edi,%ecx 8: 83 e1 07 and $0x7,%ecx b: 74 15 je 0x22 d: 83 e9 08 sub $0x8,%ecx 10: f7 d9 neg %ecx 12: 29 ca sub %ecx,%edx 14: 8a 06 mov (%rsi),%al 16: 88 07 mov %al,(%rdi) 18: 48 ff c6 inc %rsi 1b: 48 ff c7 inc %rdi 1e: ff c9 dec %ecx 20: 75 f2 jne 0x14 22: 89 d1 mov %edx,%ecx 24: c1 e9 03 shr $0x3,%ecx 27: 83 e2 07 and $0x7,%edx * 2a: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2d: 89 d1 mov %edx,%ecx 2f: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) 31: 31 c0 xor %eax,%eax 33: 0f 01 ca clac 36: e9 73 64 1d 02 jmpq 0x21d64ae 3b: 0f 1f 00 nopl (%rax) 3e: 0f .byte 0xf 3f: 01 .byte 0x1