FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
======================================================
WARNING: possible circular locking dependency detected
5.17.0-rc2-next-20220204 #1 Not tainted
------------------------------------------------------
syz-executor.6/21127 is trying to acquire lock:
ffffffff85114b60 (console_owner){-.-.}-{0:0}, at: console_unlock+0x2f4/0xae0

but task is already holding lock:
ffff8880414b5158 (&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/0xb00
       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
       default_idle+0xb/0x10
       default_idle_call+0x87/0xd0
       do_idle+0x3b9/0x530
       cpu_startup_entry+0x14/0x20
       secondary_startup_64_no_verify+0xd5/0xdb

-> #1 (&port_lock_key){-.-.}-{2:2}:
       _raw_spin_lock_irqsave+0x39/0x50
       serial8250_console_write+0x90e/0xb20
       console_unlock+0x756/0xae0
       register_console+0x378/0x7d0
       univ8250_console_init+0x3a/0x46
       console_init+0x3c1/0x58d
       start_kernel+0x301/0x4a5
       secondary_startup_64_no_verify+0xd5/0xdb

-> #0 (console_owner){-.-.}-{0:0}:
       __lock_acquire+0x2c2f/0x6120
       lock_acquire+0x1a2/0x4d0
       console_unlock+0x347/0xae0
       vprintk_emit+0x198/0x450
       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+0xa86/0xfe0
       file_tty_write.constprop.0+0x529/0x910
       new_sync_write+0x437/0x660
       vfs_write+0x7d1/0xae0
       ksys_write+0x12d/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 ***

6 locks held by syz-executor.6/21127:
 #0: ffff888017fa6098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80
 #1: ffff888017fa6130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: file_tty_write.constprop.0+0x29f/0x910
 #2: ffff888017fa62e8 (&tty->termios_rwsem){++++}-{3:3}, at: n_tty_write+0x1bf/0xfe0
 #3: ffffc9001415c378 (&ldata->output_lock){+.+.}-{3:3}, at: n_tty_write+0xa4d/0xfe0
 #4: ffff8880414b5158 (&port->lock){-.-.}-{2:2}, at: pty_write+0xea/0x1e0
 #5: ffffffff851f4fa0 (console_lock){+.+.}-{0:0}, at: vprintk+0x80/0x90

stack backtrace:
CPU: 0 PID: 21127 Comm: syz-executor.6 Not tainted 5.17.0-rc2-next-20220204 #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+0x1a2/0x4d0
 console_unlock+0x347/0xae0
 vprintk_emit+0x198/0x450
 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+0xa86/0xfe0
 file_tty_write.constprop.0+0x529/0x910
 new_sync_write+0x437/0x660
 vfs_write+0x7d1/0xae0
 ksys_write+0x12d/0x250
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f494ace8b19
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:00007f494825e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f494adfbf60 RCX: 00007f494ace8b19
RDX: 000000000000001c RSI: 0000000020000080 RDI: 0000000000000004
RBP: 00007f494825e1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffc1c12edef R14: 00007f494825e300 R15: 0000000000022000
 </TASK>
CPU: 0 PID: 21127 Comm: syz-executor.6 Not tainted 5.17.0-rc2-next-20220204 #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+0xa86/0xfe0
 file_tty_write.constprop.0+0x529/0x910
 new_sync_write+0x437/0x660
 vfs_write+0x7d1/0xae0
 ksys_write+0x12d/0x250
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f494ace8b19
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:00007f494825e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f494adfbf60 RCX: 00007f494ace8b19
RDX: 000000000000001c RSI: 0000000020000080 RDI: 0000000000000004
RBP: 00007f494825e1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffc1c12edef R14: 00007f494825e300 R15: 0000000000022000
 </TASK>
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 0 PID: 21130 Comm: syz-executor.7 Not tainted 5.17.0-rc2-next-20220204 #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
 __alloc_file+0x21/0x240
 alloc_empty_file+0x6d/0x170
 path_openat+0xe1/0x28a0
 do_filp_open+0x1aa/0x400
 do_sys_openat2+0x16d/0x4d0
 __x64_sys_openat+0x13f/0x1f0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f7a9d388b19
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:00007f7a9a8fe188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f7a9d49bf60 RCX: 00007f7a9d388b19
RDX: 0000000000101042 RSI: 0000000020000100 RDI: ffffffffffffff9c
RBP: 00007f7a9a8fe1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff419bfe1f R14: 00007f7a9a8fe300 R15: 0000000000022000
 </TASK>
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
CPU: 1 PID: 21133 Comm: syz-executor.5 Not tainted 5.17.0-rc2-next-20220204 #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
 strncpy_from_user+0x34/0x3e0
 getname_flags.part.0+0x95/0x4f0
 getname+0x8e/0xd0
 do_sys_openat2+0xf5/0x4d0
 __x64_sys_openat+0x13f/0x1f0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fd919e25b19
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:00007fd91739b188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fd919f38f60 RCX: 00007fd919e25b19
RDX: 0000000000101042 RSI: 0000000020000100 RDI: ffffffffffffff9c
RBP: 00007fd91739b1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffed9621d4f R14: 00007fd91739b300 R15: 0000000000022000
 </TASK>
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 1 PID: 21140 Comm: syz-executor.1 Not tainted 5.17.0-rc2-next-20220204 #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
 alloc_workqueue_attrs+0x38/0x80
 alloc_workqueue+0x939/0xeb0
 loop_configure+0x6ec/0x1950
 lo_ioctl+0x7c5/0x18b0
 blkdev_ioctl+0x362/0x7f0
 __x64_sys_ioctl+0x196/0x210
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f14bbac98d7
Code: 3c 1c 48 f7 d8 49 39 c4 72 b8 e8 a4 54 02 00 85 c0 78 bd 48 83 c4 08 4c 89 e0 5b 41 5c c3 0f 1f 44 00 00 b8 10 00 00 00 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:00007f14b903ef48 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f14bbb13970 RCX: 00007f14bbac98d7
RDX: 0000000000000004 RSI: 0000000000004c00 RDI: 0000000000000005
RBP: 0000000000000005 R08: 0000000000000000 R09: ffffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 0000000000000004 R14: 00000000200002c8 R15: 0000000000000003
 </TASK>