Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
======================================================
WARNING: possible circular locking dependency detected
5.18.0-rc3-next-20220422 #1 Not tainted
------------------------------------------------------
syz-executor.1/5874 is trying to acquire lock:
ffffffff851166a0 (console_owner){-.-.}-{0:0}, at: vprintk_emit+0x316/0x550

but task is already holding lock:
ffff888042d72158 (&port->lock){-.-.}-{2:2}, at: pty_write+0xea/0x1e0

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+0x39/0x50
       tty_port_tty_get+0x1f/0x100
       tty_port_default_wakeup+0x11/0x40
       serial8250_tx_chars+0x50b/0xa70
       serial8250_handle_irq.part.0+0x3f1/0x4c0
       serial8250_default_handle_irq+0xb8/0x230
       serial8250_interrupt+0xf4/0x1a0
       __handle_irq_event_percpu+0x20f/0x820
       handle_irq_event+0xa7/0x1e0
       handle_edge_irq+0x262/0xd10
       __common_interrupt+0x92/0x1d0
       common_interrupt+0x9f/0xc0
       asm_common_interrupt+0x1e/0x40
       _raw_spin_unlock_irqrestore+0x2e/0x50
       uart_write+0x304/0x580
       do_output_char+0x5e4/0x860
       n_tty_write+0x4c9/0xfd0
       file_tty_write.constprop.0+0x523/0x900
       redirected_tty_write+0xa1/0xc0
       do_iter_readv_writev+0x3d8/0x650
       do_iter_write+0x187/0x6f0
       vfs_writev+0x1aa/0x630
       do_writev+0x133/0x2f0
       do_syscall_64+0x3b/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #1 (&port_lock_key){-.-.}-{2:2}:
       _raw_spin_lock_irqsave+0x39/0x50
       serial8250_console_write+0x90e/0xb20
       console_unlock+0x8c7/0xd40
       register_console+0x378/0x7d0
       univ8250_console_init+0x3a/0x46
       console_init+0x3c1/0x58d
       start_kernel+0x301/0x4ee
       secondary_startup_64_no_verify+0xe0/0xeb

-> #0 (console_owner){-.-.}-{0:0}:
       __lock_acquire+0x2c2f/0x6120
       lock_acquire+0x1a2/0x530
       vprintk_emit+0x353/0x550
       vprintk+0x80/0x90
       _printk+0xba/0xed
       should_fail+0x472/0x5a0
       should_failslab+0x5/0x10
       __kmalloc+0x72/0x440
       tty_buffer_alloc+0x23f/0x2a0
       __tty_buffer_request_room+0x156/0x2a0
       tty_insert_flip_string_fixed_flag+0x91/0x240
       pty_write+0x11c/0x1e0
       n_tty_write+0x416/0xfd0
       file_tty_write.constprop.0+0x523/0x900
       new_sync_write+0x390/0x560
       vfs_write+0x7b9/0xac0
       ksys_write+0x127/0x250
       do_syscall_64+0x3b/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

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 ***

5 locks held by syz-executor.1/5874:
 #0: ffff8880438f0098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80
 #1: ffff8880438f0130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: file_tty_write.constprop.0+0x299/0x900
 #2: ffff8880438f02e8 (&o_tty->termios_rwsem/1){++++}-{3:3}, at: n_tty_write+0x1bf/0xfd0
 #3: ffffc90013f09378 (&ldata->output_lock){+.+.}-{3:3}, at: n_tty_write+0x542/0xfd0
 #4: ffff888042d72158 (&port->lock){-.-.}-{2:2}, at: pty_write+0xea/0x1e0

stack backtrace:
 <TASK>
 dump_stack_lvl+0x8b/0xb3
 should_fail.cold+0x5/0xa
 should_failslab+0x5/0x10
 kmem_cache_alloc+0x5b/0x480
 create_object.isra.0+0x3a/0xa20
 kmem_cache_alloc+0x239/0x480
 security_file_alloc+0x34/0x170
 __alloc_file+0xb6/0x230
 alloc_empty_file+0x6d/0x170
 path_openat+0xe1/0x2870
 do_filp_open+0x1aa/0x400
 do_sys_openat2+0x16d/0x4c0
 __x64_sys_openat+0x13f/0x1f0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f8b19397b19
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:00007f8b1690d188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f8b194aaf60 RCX: 00007f8b19397b19
RDX: 0000000000000000 RSI: 0000000020000080 RDI: ffffffffffffff9c
RBP: 00007f8b1690d1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fffe019d0cf R14: 00007f8b1690d300 R15: 0000000000022000
 </TASK>
CPU: 1 PID: 5874 Comm: syz-executor.1 Not tainted 5.18.0-rc3-next-20220422 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x8b/0xb3
 check_noncircular+0x25f/0x2e0
 __lock_acquire+0x2c2f/0x6120
 lock_acquire+0x1a2/0x530
 vprintk_emit+0x353/0x550
 vprintk+0x80/0x90
 _printk+0xba/0xed
 should_fail+0x472/0x5a0
 should_failslab+0x5/0x10
 __kmalloc+0x72/0x440
 tty_buffer_alloc+0x23f/0x2a0
 __tty_buffer_request_room+0x156/0x2a0
 tty_insert_flip_string_fixed_flag+0x91/0x240
 pty_write+0x11c/0x1e0
 n_tty_write+0x416/0xfd0
 file_tty_write.constprop.0+0x523/0x900
 new_sync_write+0x390/0x560
 vfs_write+0x7b9/0xac0
 ksys_write+0x127/0x250
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7ffbbf344b19
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:00007ffbbc8ba188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ffbbf457f60 RCX: 00007ffbbf344b19
RDX: 00000000fffffecb RSI: 0000000020000180 RDI: 0000000000000004
RBP: 00007ffbbc8ba1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffe582e2edf R14: 00007ffbbc8ba300 R15: 0000000000022000
 </TASK>
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 1 PID: 5874 Comm: syz-executor.1 Not tainted 5.18.0-rc3-next-20220422 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x8b/0xb3
 should_fail.cold+0x5/0xa
 should_failslab+0x5/0x10
 __kmalloc+0x72/0x440
 tty_buffer_alloc+0x23f/0x2a0
 __tty_buffer_request_room+0x156/0x2a0
 tty_insert_flip_string_fixed_flag+0x91/0x240
 pty_write+0x11c/0x1e0
 n_tty_write+0x416/0xfd0
 file_tty_write.constprop.0+0x523/0x900
 new_sync_write+0x390/0x560
 vfs_write+0x7b9/0xac0
 ksys_write+0x127/0x250
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7ffbbf344b19
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:00007ffbbc8ba188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ffbbf457f60 RCX: 00007ffbbf344b19
RDX: 00000000fffffecb RSI: 0000000020000180 RDI: 0000000000000004
RBP: 00007ffbbc8ba1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffe582e2edf R14: 00007ffbbc8ba300 R15: 0000000000022000
 </TASK>
CPU: 0 PID: 5878 Comm: syz-executor.4 Not tainted 5.18.0-rc3-next-20220422 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x8b/0xb3
 should_fail.cold+0x5/0xa
 should_failslab+0x5/0x10
 kmem_cache_alloc+0x5b/0x480
 skb_clone+0x170/0x3c0
 ip6_err_gen_icmpv6_unreach+0x130/0x7b0
 ipip6_err+0x3a8/0x930
 tunnel64_err+0x83/0x1d0
 icmp_socket_deliver+0x1c2/0x360
 icmp_unreach+0x338/0xad0
 icmp_rcv+0x6bc/0x17b0
 ip_protocol_deliver_rcu+0x960/0xb70
 ip_local_deliver_finish+0x2ee/0x4c0
 ip_local_deliver+0x1b3/0x200
 ip_rcv+0x1b2/0x490
 __netif_receive_skb_one_core+0x197/0x1e0
 __netif_receive_skb+0x24/0x1b0
 netif_receive_skb+0x12b/0x870
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
 tun_rx_batched.isra.0+0x462/0x710
 tun_get_user+0x2551/0x3a10
 tun_chr_write_iter+0xdb/0x1e0
 new_sync_write+0x390/0x560
 vfs_write+0x7b9/0xac0
 ksys_write+0x127/0x250
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f90606385ff
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 99 fd ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 cc fd ff ff 48
RSP: 002b:00007f905dbfb150 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f9060798f60 RCX: 00007f90606385ff
RDX: 000000000000007e RSI: 0000000020000000 RDI: 00000000000000f0
RBP: 00007f905dbfb1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 00007fffd228977f R14: 00007f905dbfb300 R15: 0000000000022000
 </TASK>
CPU: 1 PID: 5884 Comm: syz-executor.5 Not tainted 5.18.0-rc3-next-20220422 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x8b/0xb3
 should_fail.cold+0x5/0xa
 should_failslab+0x5/0x10
 kmem_cache_alloc_trace+0x55/0x3c0
 tty_alloc_file+0x3d/0xa0
 ptmx_open+0x5d/0x360
 chrdev_open+0x268/0x6d0
 do_dentry_open+0x49f/0x10b0
 path_openat+0x1a11/0x2870
 do_filp_open+0x1aa/0x400
 do_sys_openat2+0x16d/0x4c0
 __x64_sys_openat+0x13f/0x1f0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f8b19397b19
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:00007f8b1690d188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f8b194aaf60 RCX: 00007f8b19397b19
RDX: 0000000000000000 RSI: 0000000020000080 RDI: ffffffffffffff9c
RBP: 00007f8b1690d1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fffe019d0cf R14: 00007f8b1690d300 R15: 0000000000022000
 </TASK>
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 1 PID: 5892 Comm: syz-executor.5 Not tainted 5.18.0-rc3-next-20220422 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x8b/0xb3
 should_fail.cold+0x5/0xa
 should_failslab+0x5/0x10
 kmem_cache_alloc+0x5b/0x480
 create_object.isra.0+0x3a/0xa20
 kmem_cache_alloc_trace+0x22e/0x3c0
 tty_alloc_file+0x3d/0xa0
 ptmx_open+0x5d/0x360
 chrdev_open+0x268/0x6d0
 do_dentry_open+0x49f/0x10b0
 path_openat+0x1a11/0x2870
 do_filp_open+0x1aa/0x400
 do_sys_openat2+0x16d/0x4c0
 __x64_sys_openat+0x13f/0x1f0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f8b19397b19
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:00007f8b1690d188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f8b194aaf60 RCX: 00007f8b19397b19
RDX: 0000000000000000 RSI: 0000000020000080 RDI: ffffffffffffff9c
RBP: 00007f8b1690d1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fffe019d0cf R14: 00007f8b1690d300 R15: 0000000000022000
 </TASK>
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 1 PID: 5894 Comm: syz-executor.1 Not tainted 5.18.0-rc3-next-20220422 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x8b/0xb3
 should_fail.cold+0x5/0xa
 should_failslab+0x5/0x10
 kmem_cache_alloc+0x5b/0x480
 create_object.isra.0+0x3a/0xa20
 __kmalloc+0x25b/0x440
 tty_buffer_alloc+0x23f/0x2a0
 __tty_buffer_request_room+0x156/0x2a0
 tty_insert_flip_string_fixed_flag+0x91/0x240
 pty_write+0x11c/0x1e0
 n_tty_write+0x416/0xfd0
 file_tty_write.constprop.0+0x523/0x900
 new_sync_write+0x390/0x560
 vfs_write+0x7b9/0xac0
 ksys_write+0x127/0x250
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7ffbbf344b19
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:00007ffbbc8ba188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ffbbf457f60 RCX: 00007ffbbf344b19
RDX: 00000000fffffecb RSI: 0000000020000180 RDI: 0000000000000004
RBP: 00007ffbbc8ba1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffe582e2edf R14: 00007ffbbc8ba300 R15: 0000000000022000
 </TASK>
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 0 PID: 5899 Comm: syz-executor.4 Not tainted 5.18.0-rc3-next-20220422 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x8b/0xb3
 should_fail.cold+0x5/0xa
 should_failslab+0x5/0x10
 kmem_cache_alloc+0x5b/0x480
 create_object.isra.0+0x3a/0xa20
 kmem_cache_alloc+0x239/0x480
 skb_clone+0x170/0x3c0
 ip6_err_gen_icmpv6_unreach+0x130/0x7b0
 ipip6_err+0x3a8/0x930
 tunnel64_err+0x83/0x1d0
 icmp_socket_deliver+0x1c2/0x360
 icmp_unreach+0x338/0xad0
 icmp_rcv+0x6bc/0x17b0
 ip_protocol_deliver_rcu+0x960/0xb70
 ip_local_deliver_finish+0x2ee/0x4c0
 ip_local_deliver+0x1b3/0x200
 ip_rcv+0x1b2/0x490
 __netif_receive_skb_one_core+0x197/0x1e0
 __netif_receive_skb+0x24/0x1b0
 netif_receive_skb+0x12b/0x870
 tun_rx_batched.isra.0+0x462/0x710
 tun_get_user+0x2551/0x3a10
 tun_chr_write_iter+0xdb/0x1e0
 new_sync_write+0x390/0x560
 vfs_write+0x7b9/0xac0
 ksys_write+0x127/0x250
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f90606385ff
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 99 fd ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 cc fd ff ff 48
RSP: 002b:00007f905dbfb150 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f9060798f60 RCX: 00007f90606385ff
RDX: 000000000000007e RSI: 0000000020000000 RDI: 00000000000000f0
RBP: 00007f905dbfb1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 00007fffd228977f R14: 00007f905dbfb300 R15: 0000000000022000
 </TASK>