FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 1
======================================================
WARNING: possible circular locking dependency detected
5.15.163-syzkaller #0 Not tainted
------------------------------------------------------
syz.2.3/4095 is trying to acquire lock:
ffff800014b178a0 (console_owner){....}-{0:0}, at: console_trylock_spinning+0xe4/0x288 kernel/printk/printk.c:1879

but task is already holding lock:
ffff0000d3c9e158 (&port->lock){....}-{2:2}, at: tty_insert_flip_string_and_push_buffer+0x48/0x324 drivers/tty/tty_buffer.c:585

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+0xc4/0x14c kernel/locking/spinlock.c:162
       tty_port_tty_get+0x2c/0x124 drivers/tty/tty_port.c:289
       tty_port_default_wakeup+0x20/0x54 drivers/tty/tty_port.c:48
       tty_port_tty_wakeup+0x64/0x78 drivers/tty/tty_port.c:389
       uart_write_wakeup+0x4c/0x64 drivers/tty/serial/serial_core.c:111
       pl011_tx_chars+0xb00/0x1298 drivers/tty/serial/amba-pl011.c:1501
       pl011_start_tx_pio drivers/tty/serial/amba-pl011.c:1347 [inline]
       pl011_start_tx+0x570/0xbb4 drivers/tty/serial/amba-pl011.c:1389
       __uart_start drivers/tty/serial/serial_core.c:132 [inline]
       uart_write+0x62c/0x8b8 drivers/tty/serial/serial_core.c:589
       process_output_block drivers/tty/n_tty.c:592 [inline]
       n_tty_write+0xae0/0xf38 drivers/tty/n_tty.c:2339
       do_tty_write drivers/tty/tty_io.c:1038 [inline]
       file_tty_write+0x44c/0x758 drivers/tty/tty_io.c:1110
       tty_write drivers/tty/tty_io.c:1131 [inline]
       redirected_tty_write+0xc4/0x10c drivers/tty/tty_io.c:1154
       call_write_iter include/linux/fs.h:2172 [inline]
       new_sync_write fs/read_write.c:507 [inline]
       vfs_write+0x884/0xb44 fs/read_write.c:594
       ksys_write+0x15c/0x26c fs/read_write.c:647
       __do_sys_write fs/read_write.c:659 [inline]
       __se_sys_write fs/read_write.c:656 [inline]
       __arm64_sys_write+0x7c/0x90 fs/read_write.c:656
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
       el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
       el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
       el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

-> #1 (&port_lock_key){....}-{2:2}:
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0xb0/0x10c kernel/locking/spinlock.c:154
       spin_lock include/linux/spinlock.h:363 [inline]
       pl011_console_write+0x1a0/0x774 drivers/tty/serial/amba-pl011.c:2350
       call_console_drivers kernel/printk/printk.c:1959 [inline]
       console_unlock+0xbac/0x1394 kernel/printk/printk.c:2744
       register_console+0x57c/0x88c kernel/printk/printk.c:3097
       uart_configure_port drivers/tty/serial/serial_core.c:2455 [inline]
       uart_add_one_port+0x1024/0x17cc drivers/tty/serial/serial_core.c:2970
       pl011_register_port+0x1a0/0x434 drivers/tty/serial/amba-pl011.c:2795
       sbsa_uart_probe+0x474/0x5dc drivers/tty/serial/amba-pl011.c:2930
       platform_probe+0x148/0x1c0 drivers/base/platform.c:1391
       really_probe+0x26c/0xaec drivers/base/dd.c:595
       __driver_probe_device+0x194/0x3b4 drivers/base/dd.c:755
       driver_probe_device+0x78/0x34c drivers/base/dd.c:785
       __device_attach_driver+0x28c/0x4d8 drivers/base/dd.c:907
       bus_for_each_drv+0x158/0x1e0 drivers/base/bus.c:427
       __device_attach+0x2f0/0x480 drivers/base/dd.c:979
       device_initial_probe+0x24/0x34 drivers/base/dd.c:1028
       bus_probe_device+0xbc/0x1c8 drivers/base/bus.c:487
       device_add+0xae0/0xef4 drivers/base/core.c:3412
       platform_device_add+0x3f8/0x708 drivers/base/platform.c:712
       platform_device_register_full+0x508/0x618 drivers/base/platform.c:835
       acpi_create_platform_device+0x4d8/0x650 drivers/acpi/acpi_platform.c:154
       acpi_default_enumeration+0x6c/0xdc drivers/acpi/scan.c:2083
       acpi_bus_attach+0x88c/0xab4 drivers/acpi/scan.c:2193
       acpi_bus_attach+0x314/0xab4 drivers/acpi/scan.c:2199
       acpi_bus_attach+0x314/0xab4 drivers/acpi/scan.c:2199
       acpi_bus_scan+0xe4/0x20c drivers/acpi/scan.c:2371
       acpi_scan_init+0x220/0x71c drivers/acpi/scan.c:2546
       acpi_init+0x188/0x24c drivers/acpi/bus.c:1346
       do_one_initcall+0x234/0x990 init/main.c:1302
       do_initcall_level+0x154/0x214 init/main.c:1375
       do_initcalls+0x58/0xac init/main.c:1391
       do_basic_setup+0x8c/0xa0 init/main.c:1410
       kernel_init_freeable+0x460/0x640 init/main.c:1615
       kernel_init+0x24/0x294 init/main.c:1506
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870

-> #0 (console_owner){....}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x32d4/0x7638 kernel/locking/lockdep.c:5012
       lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5623
       console_trylock_spinning+0x110/0x288 kernel/printk/printk.c:1896
       vprintk_emit+0x124/0x21c kernel/printk/printk.c:2273
       vprintk_default+0xa0/0xe4 kernel/printk/printk.c:2289
       vprintk+0x200/0x2d4 kernel/printk/printk_safe.c:45
       _printk+0xdc/0x128 kernel/printk/printk.c:2299
       fail_dump lib/fault-inject.c:45 [inline]
       should_fail+0x398/0x514 lib/fault-inject.c:146
       __should_failslab+0xbc/0x110 mm/failslab.c:33
       should_failslab+0x10/0x28 mm/slab_common.c:1337
       slab_pre_alloc_hook+0x64/0xe8 mm/slab.h:494
       slab_alloc_node mm/slub.c:3134 [inline]
       slab_alloc mm/slub.c:3228 [inline]
       __kmalloc+0xc0/0x4c8 mm/slub.c:4403
       kmalloc include/linux/slab.h:596 [inline]
       tty_buffer_alloc drivers/tty/tty_buffer.c:177 [inline]
       __tty_buffer_request_room+0x1a4/0x440 drivers/tty/tty_buffer.c:276
       tty_insert_flip_string_fixed_flag drivers/tty/tty_buffer.c:322 [inline]
       tty_insert_flip_string include/linux/tty_flip.h:41 [inline]
       tty_insert_flip_string_and_push_buffer+0x74/0x324 drivers/tty/tty_buffer.c:586
       pty_write+0xb8/0xe8 drivers/tty/pty.c:118
       process_output_block drivers/tty/n_tty.c:592 [inline]
       n_tty_write+0xae0/0xf38 drivers/tty/n_tty.c:2339
       do_tty_write drivers/tty/tty_io.c:1038 [inline]
       file_tty_write+0x44c/0x758 drivers/tty/tty_io.c:1110
       tty_write+0x48/0x58 drivers/tty/tty_io.c:1131
       do_iter_readv_writev+0x420/0x5f8
       do_iter_write+0x1b8/0x66c fs/read_write.c:855
       vfs_writev fs/read_write.c:928 [inline]
       do_writev+0x220/0x3ec fs/read_write.c:971
       __do_sys_writev fs/read_write.c:1044 [inline]
       __se_sys_writev fs/read_write.c:1041 [inline]
       __arm64_sys_writev+0x80/0x94 fs/read_write.c:1041
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
       el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
       el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
       el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

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.2.3/4095:
 #0: ffff0000d8140098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
 #1: ffff0000d8140130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: tty_write_lock drivers/tty/tty_io.c:961 [inline]
 #1: ffff0000d8140130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: do_tty_write drivers/tty/tty_io.c:984 [inline]
 #1: ffff0000d8140130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: file_tty_write+0x1d4/0x758 drivers/tty/tty_io.c:1110
 #2: ffff0000d81402e8 (&o_tty->termios_rwsem/1){++++}-{3:3}, at: n_tty_write+0x1ec/0xf38 drivers/tty/n_tty.c:2322
 #3: ffff800018e84378 (&ldata->output_lock){+.+.}-{3:3}, at: process_output_block drivers/tty/n_tty.c:547 [inline]
 #3: ffff800018e84378 (&ldata->output_lock){+.+.}-{3:3}, at: n_tty_write+0x570/0xf38 drivers/tty/n_tty.c:2339
 #4: ffff0000d3c9e158 (&port->lock){....}-{2:2}, at: tty_insert_flip_string_and_push_buffer+0x48/0x324 drivers/tty/tty_buffer.c:585

stack backtrace:
CPU: 1 PID: 4095 Comm: syz.2.3 Not tainted 5.15.163-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call trace:
 dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2011
 check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x32d4/0x7638 kernel/locking/lockdep.c:5012
 lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5623
 console_trylock_spinning+0x110/0x288 kernel/printk/printk.c:1896
 vprintk_emit+0x124/0x21c kernel/printk/printk.c:2273
 vprintk_default+0xa0/0xe4 kernel/printk/printk.c:2289
 vprintk+0x200/0x2d4 kernel/printk/printk_safe.c:45
 _printk+0xdc/0x128 kernel/printk/printk.c:2299
 fail_dump lib/fault-inject.c:45 [inline]
 should_fail+0x398/0x514 lib/fault-inject.c:146
 __should_failslab+0xbc/0x110 mm/failslab.c:33
 should_failslab+0x10/0x28 mm/slab_common.c:1337
 slab_pre_alloc_hook+0x64/0xe8 mm/slab.h:494
 slab_alloc_node mm/slub.c:3134 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 __kmalloc+0xc0/0x4c8 mm/slub.c:4403
 kmalloc include/linux/slab.h:596 [inline]
 tty_buffer_alloc drivers/tty/tty_buffer.c:177 [inline]
 __tty_buffer_request_room+0x1a4/0x440 drivers/tty/tty_buffer.c:276
 tty_insert_flip_string_fixed_flag drivers/tty/tty_buffer.c:322 [inline]
 tty_insert_flip_string include/linux/tty_flip.h:41 [inline]
 tty_insert_flip_string_and_push_buffer+0x74/0x324 drivers/tty/tty_buffer.c:586
 pty_write+0xb8/0xe8 drivers/tty/pty.c:118
 process_output_block drivers/tty/n_tty.c:592 [inline]
 n_tty_write+0xae0/0xf38 drivers/tty/n_tty.c:2339
 do_tty_write drivers/tty/tty_io.c:1038 [inline]
 file_tty_write+0x44c/0x758 drivers/tty/tty_io.c:1110
 tty_write+0x48/0x58 drivers/tty/tty_io.c:1131
 do_iter_readv_writev+0x420/0x5f8
 do_iter_write+0x1b8/0x66c fs/read_write.c:855
 vfs_writev fs/read_write.c:928 [inline]
 do_writev+0x220/0x3ec fs/read_write.c:971
 __do_sys_writev fs/read_write.c:1044 [inline]
 __se_sys_writev fs/read_write.c:1041 [inline]
 __arm64_sys_writev+0x80/0x94 fs/read_write.c:1041
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
CPU: 1 PID: 4095 Comm: syz.2.3 Not tainted 5.15.163-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call trace:
 dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail+0x3b8/0x514 lib/fault-inject.c:146
 __should_failslab+0xbc/0x110 mm/failslab.c:33
 should_failslab+0x10/0x28 mm/slab_common.c:1337
 slab_pre_alloc_hook+0x64/0xe8 mm/slab.h:494
 slab_alloc_node mm/slub.c:3134 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 __kmalloc+0xc0/0x4c8 mm/slub.c:4403
 kmalloc include/linux/slab.h:596 [inline]
 tty_buffer_alloc drivers/tty/tty_buffer.c:177 [inline]
 __tty_buffer_request_room+0x1a4/0x440 drivers/tty/tty_buffer.c:276
 tty_insert_flip_string_fixed_flag drivers/tty/tty_buffer.c:322 [inline]
 tty_insert_flip_string include/linux/tty_flip.h:41 [inline]
 tty_insert_flip_string_and_push_buffer+0x74/0x324 drivers/tty/tty_buffer.c:586
 pty_write+0xb8/0xe8 drivers/tty/pty.c:118
 process_output_block drivers/tty/n_tty.c:592 [inline]
 n_tty_write+0xae0/0xf38 drivers/tty/n_tty.c:2339
 do_tty_write drivers/tty/tty_io.c:1038 [inline]
 file_tty_write+0x44c/0x758 drivers/tty/tty_io.c:1110
 tty_write+0x48/0x58 drivers/tty/tty_io.c:1131
 do_iter_readv_writev+0x420/0x5f8
 do_iter_write+0x1b8/0x66c fs/read_write.c:855
 vfs_writev fs/read_write.c:928 [inline]
 do_writev+0x220/0x3ec fs/read_write.c:971
 __do_sys_writev fs/read_write.c:1044 [inline]
 __se_sys_writev fs/read_write.c:1041 [inline]
 __arm64_sys_writev+0x80/0x94 fs/read_write.c:1041
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584