[syzbot] [ppp?] possible deadlock in ppp_asynctty_ioctl

3 views
Skip to first unread message

syzbot

unread,
Feb 21, 2024, 6:08:22ā€ÆAMFeb 21
to da...@davemloft.net, edum...@google.com, ku...@kernel.org, linux-...@vger.kernel.org, linu...@vger.kernel.org, net...@vger.kernel.org, pab...@redhat.com, syzkall...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: fca7526b7d89 drm/tests/drm_buddy: fix build failure on 32-..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=170edffc180000
kernel config: https://syzkaller.appspot.com/x/.config?x=5e7cea39e8c4d7d3
dashboard link: https://syzkaller.appspot.com/bug?extid=8e808eb853386f575d86
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ee1932a6c45a/disk-fca7526b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f525fc08e238/vmlinux-fca7526b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/cd501b251c05/bzImage-fca7526b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8e808e...@syzkaller.appspotmail.com

========================================================
WARNING: possible irq lock inversion dependency detected
6.8.0-rc5-syzkaller-00002-gfca7526b7d89 #0 Not tainted
--------------------------------------------------------
syz-executor.4/9979 just changed the state of lock:
ffffffff8ebf32f8 (disc_data_lock){.?..}-{2:2}, at: ap_get drivers/net/ppp/ppp_async.c:137 [inline]
ffffffff8ebf32f8 (disc_data_lock){.?..}-{2:2}, at: ppp_asynctty_ioctl+0x36/0x3f0 drivers/net/ppp/ppp_async.c:286
but this lock was taken by another, HARDIRQ-safe lock in the past:
(&port_lock_key){-.-.}-{2:2}


and interrupts could create inverse lock ordering between them.


other info that might help us debug this:
Possible interrupt unsafe locking scenario:

CPU0 CPU1
---- ----
lock(disc_data_lock);
local_irq_disable();
lock(&port_lock_key);
lock(disc_data_lock);
<Interrupt>
lock(&port_lock_key);

*** DEADLOCK ***

1 lock held by syz-executor.4/9979:
#0: ffff88802f1dc0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243

the shortest dependencies between 2nd lock and 1st lock:
-> (&port_lock_key){-.-.}-{2:2} {
IN-HARDIRQ-W at:
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
uart_port_lock_irqsave include/linux/serial_core.h:616 [inline]
serial8250_handle_irq+0x81/0x710 drivers/tty/serial/8250/8250_port.c:1913
serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1962
serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:127
__handle_irq_event_percpu+0x289/0xa30 kernel/irq/handle.c:158
handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
handle_irq_event+0x89/0x1f0 kernel/irq/handle.c:210
handle_edge_irq+0x25f/0xc20 kernel/irq/chip.c:831
generic_handle_irq_desc include/linux/irqdesc.h:161 [inline]
handle_irq arch/x86/kernel/irq.c:238 [inline]
__common_interrupt+0x138/0x230 arch/x86/kernel/irq.c:257
common_interrupt+0xa5/0xd0 arch/x86/kernel/irq.c:247
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:640
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
uart_port_unlock_irqrestore include/linux/serial_core.h:667 [inline]
serial_port_runtime_resume+0x204/0x2b0 drivers/tty/serial/serial_port.c:41
__rpm_callback+0x2df/0x790 drivers/base/power/runtime.c:393
rpm_callback drivers/base/power/runtime.c:447 [inline]
rpm_resume+0x10b1/0x1af0 drivers/base/power/runtime.c:913
pm_runtime_work+0x147/0x210 drivers/base/power/runtime.c:978
process_one_work kernel/workqueue.c:2633 [inline]
process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706
worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787
kthread+0x2ef/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242
IN-SOFTIRQ-W at:
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
uart_port_lock_irqsave include/linux/serial_core.h:616 [inline]
serial8250_handle_irq+0x81/0x710 drivers/tty/serial/8250/8250_port.c:1913
serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1962
serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:127
__handle_irq_event_percpu+0x289/0xa30 kernel/irq/handle.c:158
handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
handle_irq_event+0x89/0x1f0 kernel/irq/handle.c:210
handle_edge_irq+0x25f/0xc20 kernel/irq/chip.c:831
generic_handle_irq_desc include/linux/irqdesc.h:161 [inline]
handle_irq arch/x86/kernel/irq.c:238 [inline]
__common_interrupt+0x138/0x230 arch/x86/kernel/irq.c:257
common_interrupt+0x4f/0xd0 arch/x86/kernel/irq.c:247
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:640
arch_local_irq_enable arch/x86/include/asm/irqflags.h:77 [inline]
__do_softirq+0x1da/0x942 kernel/softirq.c:537
invoke_softirq kernel/softirq.c:427 [inline]
__irq_exit_rcu+0xf1/0x1c0 kernel/softirq.c:632
irq_exit_rcu+0x9/0x30 kernel/softirq.c:644
sysvec_apic_timer_interrupt+0x97/0xb0 arch/x86/kernel/apic/apic.c:1076
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649
console_flush_all+0x9cc/0xec0
console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3036
vprintk_emit+0x508/0x720 kernel/printk/printk.c:2303
_printk+0xd5/0x120 kernel/printk/printk.c:2328
check_stack_usage kernel/exit.c:785 [inline]
do_exit+0x1d41/0x2740 kernel/exit.c:914
do_group_exit+0x206/0x2c0 kernel/exit.c:1020
__do_sys_exit_group kernel/exit.c:1031 [inline]
__se_sys_exit_group kernel/exit.c:1029 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1029
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
INITIAL USE at:
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
uart_port_lock_irqsave include/linux/serial_core.h:616 [inline]
serial8250_do_set_termios+0x531/0x17e0 drivers/tty/serial/8250/8250_port.c:2793
uart_set_options+0x3eb/0x730 drivers/tty/serial/serial_core.c:2320
serial8250_console_setup+0x3db/0x670 drivers/tty/serial/8250/8250_port.c:3507
univ8250_console_setup+0x3ac/0x470 drivers/tty/serial/8250/8250_core.c:632
try_enable_preferred_console+0x40d/0x560 kernel/printk/printk.c:3302
register_console+0x261/0xcd0 kernel/printk/printk.c:3479
univ8250_console_init+0x49/0x50 drivers/tty/serial/8250/8250_core.c:717
console_init+0x198/0x680 kernel/printk/printk.c:3688
start_kernel+0x2d2/0x500 init/main.c:1008
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:536
secondary_startup_64_no_verify+0x171/0x17b
}
... key at: [<ffffffff9477a680>] port_lock_key+0x0/0x20
... acquired at:
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
_raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
ap_get drivers/net/ppp/ppp_async.c:137 [inline]
ppp_asynctty_wakeup+0x20/0x210 drivers/net/ppp/ppp_async.c:353
tty_wakeup+0xbb/0x100 drivers/tty/tty_io.c:523
tty_port_default_wakeup+0xa6/0xf0 drivers/tty/tty_port.c:69
serial8250_tx_chars+0x6ad/0x8a0 drivers/tty/serial/8250/8250_port.c:1835
serial8250_handle_irq+0x558/0x710 drivers/tty/serial/8250/8250_port.c:1942
serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1962
serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:127
__handle_irq_event_percpu+0x289/0xa30 kernel/irq/handle.c:158
handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
handle_irq_event+0x89/0x1f0 kernel/irq/handle.c:210
handle_edge_irq+0x25f/0xc20 kernel/irq/chip.c:831
generic_handle_irq_desc include/linux/irqdesc.h:161 [inline]
handle_irq arch/x86/kernel/irq.c:238 [inline]
__common_interrupt+0x138/0x230 arch/x86/kernel/irq.c:257
common_interrupt+0xa5/0xd0 arch/x86/kernel/irq.c:247
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:640
check_kcov_mode kernel/kcov.c:175 [inline]
write_comp_data kernel/kcov.c:236 [inline]
__sanitizer_cov_trace_cmp8+0x34/0x90 kernel/kcov.c:284
on_stack arch/x86/include/asm/stacktrace.h:60 [inline]
unwind_next_frame+0x1df4/0x29e0 arch/x86/kernel/unwind_orc.c:665
arch_stack_walk+0x150/0x1b0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x117/0x1d0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x4e/0x60 mm/kasan/generic.c:640
poison_slab_object+0xa6/0xe0 mm/kasan/common.c:241
__kasan_slab_free+0x34/0x70 mm/kasan/common.c:257
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2121 [inline]
slab_free mm/slub.c:4299 [inline]
kmem_cache_free+0x102/0x2a0 mm/slub.c:4363
vma_lock_free kernel/fork.c:451 [inline]
__vm_area_free+0xe0/0x110 kernel/fork.c:507
remove_vma mm/mmap.c:146 [inline]
exit_mmap+0x6a9/0xd40 mm/mmap.c:3303
__mmput+0x115/0x3c0 kernel/fork.c:1343
exit_mm+0x21f/0x310 kernel/exit.c:569
do_exit+0x9af/0x2740 kernel/exit.c:858
do_group_exit+0x206/0x2c0 kernel/exit.c:1020
__do_sys_exit_group kernel/exit.c:1031 [inline]
__se_sys_exit_group kernel/exit.c:1029 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1029
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77

-> (disc_data_lock){.?..}-{2:2} {
IN-HARDIRQ-R at:
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
_raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
ap_get drivers/net/ppp/ppp_async.c:137 [inline]
ppp_asynctty_wakeup+0x20/0x210 drivers/net/ppp/ppp_async.c:353
tty_wakeup+0xbb/0x100 drivers/tty/tty_io.c:523
tty_port_default_wakeup+0xa6/0xf0 drivers/tty/tty_port.c:69
serial8250_tx_chars+0x6ad/0x8a0 drivers/tty/serial/8250/8250_port.c:1835
serial8250_handle_irq+0x558/0x710 drivers/tty/serial/8250/8250_port.c:1942
serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1962
serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:127
__handle_irq_event_percpu+0x289/0xa30 kernel/irq/handle.c:158
handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
handle_irq_event+0x89/0x1f0 kernel/irq/handle.c:210
handle_edge_irq+0x25f/0xc20 kernel/irq/chip.c:831
generic_handle_irq_desc include/linux/irqdesc.h:161 [inline]
handle_irq arch/x86/kernel/irq.c:238 [inline]
__common_interrupt+0x138/0x230 arch/x86/kernel/irq.c:257
common_interrupt+0xa5/0xd0 arch/x86/kernel/irq.c:247
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:640
check_kcov_mode kernel/kcov.c:175 [inline]
write_comp_data kernel/kcov.c:236 [inline]
__sanitizer_cov_trace_cmp8+0x34/0x90 kernel/kcov.c:284
on_stack arch/x86/include/asm/stacktrace.h:60 [inline]
unwind_next_frame+0x1df4/0x29e0 arch/x86/kernel/unwind_orc.c:665
arch_stack_walk+0x150/0x1b0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x117/0x1d0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x4e/0x60 mm/kasan/generic.c:640
poison_slab_object+0xa6/0xe0 mm/kasan/common.c:241
__kasan_slab_free+0x34/0x70 mm/kasan/common.c:257
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2121 [inline]
slab_free mm/slub.c:4299 [inline]
kmem_cache_free+0x102/0x2a0 mm/slub.c:4363
vma_lock_free kernel/fork.c:451 [inline]
__vm_area_free+0xe0/0x110 kernel/fork.c:507
remove_vma mm/mmap.c:146 [inline]
exit_mmap+0x6a9/0xd40 mm/mmap.c:3303
__mmput+0x115/0x3c0 kernel/fork.c:1343
exit_mm+0x21f/0x310 kernel/exit.c:569
do_exit+0x9af/0x2740 kernel/exit.c:858
do_group_exit+0x206/0x2c0 kernel/exit.c:1020
__do_sys_exit_group kernel/exit.c:1031 [inline]
__se_sys_exit_group kernel/exit.c:1029 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1029
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
HARDIRQ-ON-R at:
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
_raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
ap_get drivers/net/ppp/ppp_async.c:137 [inline]
ppp_asynctty_ioctl+0x36/0x3f0 drivers/net/ppp/ppp_async.c:286
tty_ioctl+0x99d/0xdc0 drivers/tty/tty_io.c:2812
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:857
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
INITIAL USE at:
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
_raw_write_lock_irq+0xd3/0x120 kernel/locking/spinlock.c:326
ppp_asynctty_close+0x29/0x190 drivers/net/ppp/ppp_async.c:220
tty_ldisc_kill+0xa3/0x1a0 drivers/tty/tty_ldisc.c:607
tty_ldisc_release+0x174/0x200 drivers/tty/tty_ldisc.c:775
tty_release_struct+0x2b/0xe0 drivers/tty/tty_io.c:1696
tty_release+0xd0c/0x12c0 drivers/tty/tty_io.c:1867
__fput+0x429/0x8a0 fs/file_table.c:376
__do_sys_close fs/open.c:1554 [inline]
__se_sys_close fs/open.c:1539 [inline]
__x64_sys_close+0x7e/0x110 fs/open.c:1539
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
INITIAL READ USE at:
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
_raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
ap_get drivers/net/ppp/ppp_async.c:137 [inline]
ppp_asynctty_wakeup+0x20/0x210 drivers/net/ppp/ppp_async.c:353
tty_wakeup+0xbb/0x100 drivers/tty/tty_io.c:523
tty_port_default_wakeup+0xa6/0xf0 drivers/tty/tty_port.c:69
serial8250_tx_chars+0x6ad/0x8a0 drivers/tty/serial/8250/8250_port.c:1835
serial8250_handle_irq+0x558/0x710 drivers/tty/serial/8250/8250_port.c:1942
serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1962
serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:127
__handle_irq_event_percpu+0x289/0xa30 kernel/irq/handle.c:158
handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
handle_irq_event+0x89/0x1f0 kernel/irq/handle.c:210
handle_edge_irq+0x25f/0xc20 kernel/irq/chip.c:831
generic_handle_irq_desc include/linux/irqdesc.h:161 [inline]
handle_irq arch/x86/kernel/irq.c:238 [inline]
__common_interrupt+0x138/0x230 arch/x86/kernel/irq.c:257
common_interrupt+0xa5/0xd0 arch/x86/kernel/irq.c:247
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:640
check_kcov_mode kernel/kcov.c:175 [inline]
write_comp_data kernel/kcov.c:236 [inline]
__sanitizer_cov_trace_cmp8+0x34/0x90 kernel/kcov.c:284
on_stack arch/x86/include/asm/stacktrace.h:60 [inline]
unwind_next_frame+0x1df4/0x29e0 arch/x86/kernel/unwind_orc.c:665
arch_stack_walk+0x150/0x1b0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x117/0x1d0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x4e/0x60 mm/kasan/generic.c:640
poison_slab_object+0xa6/0xe0 mm/kasan/common.c:241
__kasan_slab_free+0x34/0x70 mm/kasan/common.c:257
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2121 [inline]
slab_free mm/slub.c:4299 [inline]
kmem_cache_free+0x102/0x2a0 mm/slub.c:4363
vma_lock_free kernel/fork.c:451 [inline]
__vm_area_free+0xe0/0x110 kernel/fork.c:507
remove_vma mm/mmap.c:146 [inline]
exit_mmap+0x6a9/0xd40 mm/mmap.c:3303
__mmput+0x115/0x3c0 kernel/fork.c:1343
exit_mm+0x21f/0x310 kernel/exit.c:569
do_exit+0x9af/0x2740 kernel/exit.c:858
do_group_exit+0x206/0x2c0 kernel/exit.c:1020
__do_sys_exit_group kernel/exit.c:1031 [inline]
__se_sys_exit_group kernel/exit.c:1029 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1029
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
}
... key at: [<ffffffff8ebf32f8>] disc_data_lock+0x18/0x60
... acquired at:
mark_lock+0x223/0x350 kernel/locking/lockdep.c:4678
mark_usage kernel/locking/lockdep.c:4579 [inline]
__lock_acquire+0x10e0/0x1fd0 kernel/locking/lockdep.c:5091
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
_raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
ap_get drivers/net/ppp/ppp_async.c:137 [inline]
ppp_asynctty_ioctl+0x36/0x3f0 drivers/net/ppp/ppp_async.c:286
tty_ioctl+0x99d/0xdc0 drivers/tty/tty_io.c:2812
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:857
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77


stack backtrace:
CPU: 1 PID: 9979 Comm: syz-executor.4 Not tainted 6.8.0-rc5-syzkaller-00002-gfca7526b7d89 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
mark_lock_irq+0x867/0xc20 kernel/locking/lockdep.c:4236
mark_lock+0x223/0x350 kernel/locking/lockdep.c:4678
mark_usage kernel/locking/lockdep.c:4579 [inline]
__lock_acquire+0x10e0/0x1fd0 kernel/locking/lockdep.c:5091
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
_raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
ap_get drivers/net/ppp/ppp_async.c:137 [inline]
ppp_asynctty_ioctl+0x36/0x3f0 drivers/net/ppp/ppp_async.c:286
tty_ioctl+0x99d/0xdc0 drivers/tty/tty_io.c:2812
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:857
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7f4028e7dda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4029c0b0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f4028fabf80 RCX: 00007f4028e7dda9
RDX: 0000000000000000 RSI: 000000000000540b RDI: 0000000000000003
RBP: 00007f4028eca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f4028fabf80 R15: 00007ffc181829f8
</TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup
Reply all
Reply to author
Forward
0 new messages