[syzbot] [serial?] possible deadlock in kbd_event
2 views
Skip to first unread message
syzbot
Oct 13, 2025, 8:10:36 PM (9 hours ago) Oct 13
to amir...@gmail.com, gre...@linuxfoundation.org, ja...@suse.cz, linux-...@vger.kernel.org, linux-...@vger.kernel.org, linux-...@vger.kernel.org, syzkall...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 3a8660878839 Linux 6.18-rc1
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=108fb9e2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9ad7b090a18654a7
dashboard link: https://syzkaller.appspot.com/bug?extid=781c8bb5e4d62cc883d3
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/25b4c153ce2b/disk-3a866087.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d46ef21feab1/vmlinux-3a866087.xz
kernel image: https://storage.googleapis.com/syzbot-assets/92d86bf0b54b/bzImage-3a866087.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+781c8b...@syzkaller.appspotmail.com
=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
syzkaller #0 Not tainted
-----------------------------------------------------
syz.8.7222/28053 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffff888077eaec90 (&new->fa_lock){....}-{3:3}, at: kill_fasync_rcu fs/fcntl.c:1122 [inline]
ffff888077eaec90 (&new->fa_lock){....}-{3:3}, at: kill_fasync+0x199/0x4d0 fs/fcntl.c:1146
and this task is already holding:
ffff88802ca16468 (&tty->flow.lock){....}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline]
ffff88802ca16468 (&tty->flow.lock){....}-{3:3}, at: start_tty+0x20/0x70 drivers/tty/tty_io.c:793
which would create a new lock dependency:
(&tty->flow.lock){....}-{3:3} -> (&new->fa_lock){....}-{3:3}
but this new dependency connects a SOFTIRQ-irq-safe lock:
(kbd_event_lock){..-.}-{3:3}
... which became SOFTIRQ-irq-safe at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
kbd_event+0xd2/0x3f70 drivers/tty/vt/keyboard.c:1528
input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541
input_pass_values+0x288/0x890 drivers/input/input.c:128
input_event_dispose+0x3e5/0x6b0 drivers/input/input.c:353
input_inject_event+0x1dd/0x340 drivers/input/input.c:424
kd_sound_helper+0x19f/0x210 drivers/tty/vt/keyboard.c:261
input_handler_for_each_handle+0x101/0x1c0 drivers/input/input.c:2520
call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747
expire_timers kernel/time/timer.c:1798 [inline]
__run_timers kernel/time/timer.c:2372 [inline]
__run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
run_timer_base kernel/time/timer.c:2393 [inline]
run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
handle_softirqs+0x286/0x870 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
check_kcov_mode kernel/kcov.c:185 [inline]
write_comp_data kernel/kcov.c:246 [inline]
__sanitizer_cov_trace_const_cmp8+0x37/0x90 kernel/kcov.c:321
__copy_present_ptes mm/memory.c:1093 [inline]
copy_present_ptes mm/memory.c:1179 [inline]
copy_pte_range mm/memory.c:1302 [inline]
copy_pmd_range+0x220d/0x7f00 mm/memory.c:1389
copy_pud_range mm/memory.c:1426 [inline]
copy_p4d_range mm/memory.c:1450 [inline]
copy_page_range+0xc14/0x1270 mm/memory.c:1538
dup_mmap+0xf4c/0x1b10 mm/mmap.c:1834
dup_mm kernel/fork.c:1489 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1541
copy_process+0x1706/0x3c00 kernel/fork.c:2181
kernel_clone+0x21e/0x840 kernel/fork.c:2609
__do_sys_clone kernel/fork.c:2750 [inline]
__se_sys_clone kernel/fork.c:2734 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
to a SOFTIRQ-irq-unsafe lock:
(tasklist_lock){.+.+}-{3:3}
... which became SOFTIRQ-irq-unsafe at:
...
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
_raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
__do_wait+0xde/0x740 kernel/exit.c:1667
do_wait+0x1f8/0x510 kernel/exit.c:1711
kernel_wait+0xab/0x170 kernel/exit.c:1887
call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
other info that might help us debug this:
Chain exists of:
kbd_event_lock --> &tty->flow.lock --> tasklist_lock
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(tasklist_lock);
local_irq_disable();
lock(kbd_event_lock);
lock(&tty->flow.lock);
<Interrupt>
lock(kbd_event_lock);
*** DEADLOCK ***
6 locks held by syz.8.7222/28053:
#0: ffff88802ca160a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffff88802ca162e8 (&tty->termios_rwsem/1){++++}-{4:4}, at: tty_set_termios+0x138/0x17e0 drivers/tty/tty_ioctl.c:333
#2: ffff88802ca160a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x1c/0x90 drivers/tty/tty_ldisc.c:263
#3: ffff88802ca16468 (&tty->flow.lock){....}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline]
#3: ffff88802ca16468 (&tty->flow.lock){....}-{3:3}, at: start_tty+0x20/0x70 drivers/tty/tty_io.c:793
#4: ffff88802ca160a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x1c/0x90 drivers/tty/tty_ldisc.c:263
#5: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#5: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#5: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: kill_fasync+0x53/0x4d0 fs/fcntl.c:1145
the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
-> (kbd_event_lock){..-.}-{3:3} {
IN-SOFTIRQ-W at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
kbd_event+0xd2/0x3f70 drivers/tty/vt/keyboard.c:1528
input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541
input_pass_values+0x288/0x890 drivers/input/input.c:128
input_event_dispose+0x3e5/0x6b0 drivers/input/input.c:353
input_inject_event+0x1dd/0x340 drivers/input/input.c:424
kd_sound_helper+0x19f/0x210 drivers/tty/vt/keyboard.c:261
input_handler_for_each_handle+0x101/0x1c0 drivers/input/input.c:2520
call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747
expire_timers kernel/time/timer.c:1798 [inline]
__run_timers kernel/time/timer.c:2372 [inline]
__run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
run_timer_base kernel/time/timer.c:2393 [inline]
run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
handle_softirqs+0x286/0x870 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
check_kcov_mode kernel/kcov.c:185 [inline]
write_comp_data kernel/kcov.c:246 [inline]
__sanitizer_cov_trace_const_cmp8+0x37/0x90 kernel/kcov.c:321
__copy_present_ptes mm/memory.c:1093 [inline]
copy_present_ptes mm/memory.c:1179 [inline]
copy_pte_range mm/memory.c:1302 [inline]
copy_pmd_range+0x220d/0x7f00 mm/memory.c:1389
copy_pud_range mm/memory.c:1426 [inline]
copy_p4d_range mm/memory.c:1450 [inline]
copy_page_range+0xc14/0x1270 mm/memory.c:1538
dup_mmap+0xf4c/0x1b10 mm/mmap.c:1834
dup_mm kernel/fork.c:1489 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1541
copy_process+0x1706/0x3c00 kernel/fork.c:2181
kernel_clone+0x21e/0x840 kernel/fork.c:2609
__do_sys_clone kernel/fork.c:2750 [inline]
__se_sys_clone kernel/fork.c:2734 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
INITIAL USE at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
vt_reset_unicode+0x2b/0x160 drivers/tty/vt/keyboard.c:2187
reset_vc+0x68/0x1b0 drivers/tty/vt/vt_ioctl.c:966
vc_init+0x70/0x4a0 drivers/tty/vt/vt.c:3728
con_init+0x385/0x9c0 drivers/tty/vt/vt.c:3793
console_init+0x10e/0x430 kernel/printk/printk.c:4298
start_kernel+0x254/0x410 init/main.c:1048
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147
}
... key at: [<ffffffff8e96ee78>] kbd_event_lock+0x18/0xa0 keyboard.c:-1
-> (&tty->flow.lock){....}-{3:3} {
INITIAL USE at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline]
start_tty+0x20/0x70 drivers/tty/tty_io.c:793
n_tty_set_termios+0xa7c/0x1090 drivers/tty/n_tty.c:1858
tty_set_termios+0xda4/0x17e0 drivers/tty/tty_ioctl.c:348
set_termios+0x516/0x6c0 drivers/tty/tty_ioctl.c:516
tty_mode_ioctl+0x47e/0x740 drivers/tty/tty_ioctl.c:-1
tty_ioctl+0x9c6/0xde0 drivers/tty/tty_io.c:2801
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
}
... key at: [<ffffffff99d18ce0>] alloc_tty_struct.__key.35+0x0/0x20
... acquired at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline]
stop_tty+0x2f/0x150 drivers/tty/tty_io.c:765
kbd_keycode drivers/tty/vt/keyboard.c:1515 [inline]
kbd_event+0x2b72/0x3f70 drivers/tty/vt/keyboard.c:1534
input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541
input_pass_values+0x288/0x890 drivers/input/input.c:128
input_event_dispose+0x330/0x6b0 drivers/input/input.c:342
input_inject_event+0x1dd/0x340 drivers/input/input.c:424
evdev_write+0x2fc/0x480 drivers/input/evdev.c:528
vfs_write+0x27e/0xb30 fs/read_write.c:684
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
the dependencies between the lock to be acquired
and SOFTIRQ-irq-unsafe lock:
-> (tasklist_lock){.+.+}-{3:3} {
HARDIRQ-ON-R at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
_raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
__do_wait+0xde/0x740 kernel/exit.c:1667
do_wait+0x1f8/0x510 kernel/exit.c:1711
kernel_wait+0xab/0x170 kernel/exit.c:1887
call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
SOFTIRQ-ON-R at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
_raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
__do_wait+0xde/0x740 kernel/exit.c:1667
do_wait+0x1f8/0x510 kernel/exit.c:1711
kernel_wait+0xab/0x170 kernel/exit.c:1887
call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INITIAL USE at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
_raw_write_lock_irq+0xa2/0xf0 kernel/locking/spinlock.c:326
copy_process+0x224f/0x3c00 kernel/fork.c:2327
kernel_clone+0x21e/0x840 kernel/fork.c:2609
user_mode_thread+0xdd/0x140 kernel/fork.c:2685
rest_init+0x23/0x300 init/main.c:722
start_kernel+0x3ae/0x410 init/main.c:1111
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147
INITIAL READ USE at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
_raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
__do_wait+0xde/0x740 kernel/exit.c:1667
do_wait+0x1f8/0x510 kernel/exit.c:1711
kernel_wait+0xab/0x170 kernel/exit.c:1887
call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
}
... key at: [<ffffffff8de0c058>] tasklist_lock+0x18/0x40
... acquired at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
_raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
send_sigio+0x101/0x370 fs/fcntl.c:919
dnotify_handle_event+0x169/0x440 fs/notify/dnotify/dnotify.c:113
fsnotify_handle_event fs/notify/fsnotify.c:350 [inline]
send_to_group fs/notify/fsnotify.c:424 [inline]
fsnotify+0x1671/0x1a80 fs/notify/fsnotify.c:641
__fsnotify_parent+0x3fe/0x540 fs/notify/fsnotify.c:287
fsnotify_parent include/linux/fsnotify.h:96 [inline]
fsnotify_path include/linux/fsnotify.h:113 [inline]
fsnotify_file include/linux/fsnotify.h:127 [inline]
fsnotify_modify include/linux/fsnotify.h:433 [inline]
vfs_writev+0x77d/0x960 fs/read_write.c:1061
do_pwritev fs/read_write.c:1153 [inline]
__do_sys_pwritev2 fs/read_write.c:1211 [inline]
__se_sys_pwritev2+0x179/0x290 fs/read_write.c:1202
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> (&f_owner->lock){....}-{3:3} {
INITIAL USE at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
_raw_write_lock_irq+0xa2/0xf0 kernel/locking/spinlock.c:326
__f_setown+0x67/0x370 fs/fcntl.c:136
fcntl_dirnotify+0x3fa/0x6a0 fs/notify/dnotify/dnotify.c:369
do_fcntl+0x6d0/0x1910 fs/fcntl.c:537
__do_sys_fcntl fs/fcntl.c:589 [inline]
__se_sys_fcntl+0xc8/0x150 fs/fcntl.c:574
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
INITIAL READ USE at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
_raw_read_lock_irqsave+0xaf/0x100 kernel/locking/spinlock.c:236
send_sigio+0x38/0x370 fs/fcntl.c:905
kill_fasync_rcu fs/fcntl.c:1131 [inline]
kill_fasync+0x24d/0x4d0 fs/fcntl.c:1146
lease_break_callback+0x26/0x30 fs/locks.c:558
__break_lease+0x6a5/0x1620 fs/locks.c:1592
break_lease include/linux/filelock.h:446 [inline]
do_dentry_open+0x8b7/0x13f0 fs/open.c:956
vfs_open+0x3b/0x340 fs/open.c:1097
do_open fs/namei.c:3975 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4134
do_filp_open+0x1fa/0x410 fs/namei.c:4161
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_open fs/open.c:1460 [inline]
__se_sys_open fs/open.c:1456 [inline]
__x64_sys_open+0x11e/0x150 fs/open.c:1456
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
}
... key at: [<ffffffff99a3b880>] file_f_owner_allocate.__key+0x0/0x20
... acquired at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
_raw_read_lock_irqsave+0xaf/0x100 kernel/locking/spinlock.c:236
send_sigio+0x38/0x370 fs/fcntl.c:905
kill_fasync_rcu fs/fcntl.c:1131 [inline]
kill_fasync+0x24d/0x4d0 fs/fcntl.c:1146
lease_break_callback+0x26/0x30 fs/locks.c:558
__break_lease+0x6a5/0x1620 fs/locks.c:1592
break_lease include/linux/filelock.h:446 [inline]
do_dentry_open+0x8b7/0x13f0 fs/open.c:956
vfs_open+0x3b/0x340 fs/open.c:1097
do_open fs/namei.c:3975 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4134
do_filp_open+0x1fa/0x410 fs/namei.c:4161
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_open fs/open.c:1460 [inline]
__se_sys_open fs/open.c:1456 [inline]
__x64_sys_open+0x11e/0x150 fs/open.c:1456
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> (&new->fa_lock){....}-{3:3} {
INITIAL USE at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
_raw_write_lock_irq+0xa2/0xf0 kernel/locking/spinlock.c:326
fasync_remove_entry+0xf1/0x1c0 fs/fcntl.c:999
pipe_fasync+0xa9/0x1e0 fs/pipe.c:756
__fput+0x8a2/0xa70 fs/file_table.c:465
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
INITIAL READ USE at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
_raw_read_lock_irqsave+0xaf/0x100 kernel/locking/spinlock.c:236
kill_fasync_rcu fs/fcntl.c:1122 [inline]
kill_fasync+0x199/0x4d0 fs/fcntl.c:1146
sock_wake_async+0x137/0x160 net/socket.c:-1
sk_wake_async+0x184/0x280 include/net/sock.h:2539
mptcp_destroy_common+0x152/0x320 net/mptcp/protocol.c:3385
mptcp_disconnect+0x23d/0x700 net/mptcp/protocol.c:3197
inet_shutdown+0x1c4/0x390 net/ipv4/af_inet.c:937
__sys_shutdown_sock net/socket.c:2470 [inline]
__sys_shutdown net/socket.c:2486 [inline]
__do_sys_shutdown net/socket.c:2491 [inline]
__se_sys_shutdown net/socket.c:2489 [inline]
__x64_sys_shutdown+0x13f/0x1a0 net/socket.c:2489
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
}
... key at: [<ffffffff99a3b8a0>] fasync_insert_entry.__key+0x0/0x20
... acquired at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
_raw_read_lock_irqsave+0xaf/0x100 kernel/locking/spinlock.c:236
kill_fasync_rcu fs/fcntl.c:1122 [inline]
kill_fasync+0x199/0x4d0 fs/fcntl.c:1146
tty_wakeup drivers/tty/tty_io.c:515 [inline]
__start_tty+0x18c/0x220 drivers/tty/tty_io.c:777
start_tty+0x2b/0x70 drivers/tty/tty_io.c:794
n_tty_set_termios+0xa7c/0x1090 drivers/tty/n_tty.c:1858
tty_set_termios+0xda4/0x17e0 drivers/tty/tty_ioctl.c:348
set_termios+0x516/0x6c0 drivers/tty/tty_ioctl.c:516
tty_mode_ioctl+0x47e/0x740 drivers/tty/tty_ioctl.c:-1
tty_ioctl+0x9c6/0xde0 drivers/tty/tty_io.c:2801
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
stack backtrace:
CPU: 0 UID: 0 PID: 28053 Comm: syz.8.7222 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_bad_irq_dependency kernel/locking/lockdep.c:2616 [inline]
check_irq_usage kernel/locking/lockdep.c:2857 [inline]
check_prev_add kernel/locking/lockdep.c:3169 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain+0x1f05/0x2140 kernel/locking/lockdep.c:3908
__lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
_raw_read_lock_irqsave+0xaf/0x100 kernel/locking/spinlock.c:236
kill_fasync_rcu fs/fcntl.c:1122 [inline]
kill_fasync+0x199/0x4d0 fs/fcntl.c:1146
tty_wakeup drivers/tty/tty_io.c:515 [inline]
__start_tty+0x18c/0x220 drivers/tty/tty_io.c:777
start_tty+0x2b/0x70 drivers/tty/tty_io.c:794
n_tty_set_termios+0xa7c/0x1090 drivers/tty/n_tty.c:1858
tty_set_termios+0xda4/0x17e0 drivers/tty/tty_ioctl.c:348
set_termios+0x516/0x6c0 drivers/tty/tty_ioctl.c:516
tty_mode_ioctl+0x47e/0x740 drivers/tty/tty_ioctl.c:-1
tty_ioctl+0x9c6/0xde0 drivers/tty/tty_io.c:2801
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f157ff8eec9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1580d69038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f15801e6090 RCX: 00007f157ff8eec9
RDX: 0000200000000140 RSI: 0000000000005402 RDI: 0000000000000004
RBP: 00007f1580011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f15801e6128 R14: 00007f15801e6090 R15: 00007f158030fa28
</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
syzbot found the following issue on:
HEAD commit: 3a8660878839 Linux 6.18-rc1
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=108fb9e2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9ad7b090a18654a7
dashboard link: https://syzkaller.appspot.com/bug?extid=781c8bb5e4d62cc883d3
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/25b4c153ce2b/disk-3a866087.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d46ef21feab1/vmlinux-3a866087.xz
kernel image: https://storage.googleapis.com/syzbot-assets/92d86bf0b54b/bzImage-3a866087.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+781c8b...@syzkaller.appspotmail.com
=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
syzkaller #0 Not tainted
-----------------------------------------------------
syz.8.7222/28053 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffff888077eaec90 (&new->fa_lock){....}-{3:3}, at: kill_fasync_rcu fs/fcntl.c:1122 [inline]
ffff888077eaec90 (&new->fa_lock){....}-{3:3}, at: kill_fasync+0x199/0x4d0 fs/fcntl.c:1146
and this task is already holding:
ffff88802ca16468 (&tty->flow.lock){....}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline]
ffff88802ca16468 (&tty->flow.lock){....}-{3:3}, at: start_tty+0x20/0x70 drivers/tty/tty_io.c:793
which would create a new lock dependency:
(&tty->flow.lock){....}-{3:3} -> (&new->fa_lock){....}-{3:3}
but this new dependency connects a SOFTIRQ-irq-safe lock:
(kbd_event_lock){..-.}-{3:3}
... which became SOFTIRQ-irq-safe at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
kbd_event+0xd2/0x3f70 drivers/tty/vt/keyboard.c:1528
input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541
input_pass_values+0x288/0x890 drivers/input/input.c:128
input_event_dispose+0x3e5/0x6b0 drivers/input/input.c:353
input_inject_event+0x1dd/0x340 drivers/input/input.c:424
kd_sound_helper+0x19f/0x210 drivers/tty/vt/keyboard.c:261
input_handler_for_each_handle+0x101/0x1c0 drivers/input/input.c:2520
call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747
expire_timers kernel/time/timer.c:1798 [inline]
__run_timers kernel/time/timer.c:2372 [inline]
__run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
run_timer_base kernel/time/timer.c:2393 [inline]
run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
handle_softirqs+0x286/0x870 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
check_kcov_mode kernel/kcov.c:185 [inline]
write_comp_data kernel/kcov.c:246 [inline]
__sanitizer_cov_trace_const_cmp8+0x37/0x90 kernel/kcov.c:321
__copy_present_ptes mm/memory.c:1093 [inline]
copy_present_ptes mm/memory.c:1179 [inline]
copy_pte_range mm/memory.c:1302 [inline]
copy_pmd_range+0x220d/0x7f00 mm/memory.c:1389
copy_pud_range mm/memory.c:1426 [inline]
copy_p4d_range mm/memory.c:1450 [inline]
copy_page_range+0xc14/0x1270 mm/memory.c:1538
dup_mmap+0xf4c/0x1b10 mm/mmap.c:1834
dup_mm kernel/fork.c:1489 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1541
copy_process+0x1706/0x3c00 kernel/fork.c:2181
kernel_clone+0x21e/0x840 kernel/fork.c:2609
__do_sys_clone kernel/fork.c:2750 [inline]
__se_sys_clone kernel/fork.c:2734 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
to a SOFTIRQ-irq-unsafe lock:
(tasklist_lock){.+.+}-{3:3}
... which became SOFTIRQ-irq-unsafe at:
...
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
_raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
__do_wait+0xde/0x740 kernel/exit.c:1667
do_wait+0x1f8/0x510 kernel/exit.c:1711
kernel_wait+0xab/0x170 kernel/exit.c:1887
call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
other info that might help us debug this:
Chain exists of:
kbd_event_lock --> &tty->flow.lock --> tasklist_lock
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(tasklist_lock);
local_irq_disable();
lock(kbd_event_lock);
lock(&tty->flow.lock);
<Interrupt>
lock(kbd_event_lock);
*** DEADLOCK ***
6 locks held by syz.8.7222/28053:
#0: ffff88802ca160a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffff88802ca162e8 (&tty->termios_rwsem/1){++++}-{4:4}, at: tty_set_termios+0x138/0x17e0 drivers/tty/tty_ioctl.c:333
#2: ffff88802ca160a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x1c/0x90 drivers/tty/tty_ldisc.c:263
#3: ffff88802ca16468 (&tty->flow.lock){....}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline]
#3: ffff88802ca16468 (&tty->flow.lock){....}-{3:3}, at: start_tty+0x20/0x70 drivers/tty/tty_io.c:793
#4: ffff88802ca160a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x1c/0x90 drivers/tty/tty_ldisc.c:263
#5: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#5: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#5: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: kill_fasync+0x53/0x4d0 fs/fcntl.c:1145
the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
-> (kbd_event_lock){..-.}-{3:3} {
IN-SOFTIRQ-W at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
kbd_event+0xd2/0x3f70 drivers/tty/vt/keyboard.c:1528
input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541
input_pass_values+0x288/0x890 drivers/input/input.c:128
input_event_dispose+0x3e5/0x6b0 drivers/input/input.c:353
input_inject_event+0x1dd/0x340 drivers/input/input.c:424
kd_sound_helper+0x19f/0x210 drivers/tty/vt/keyboard.c:261
input_handler_for_each_handle+0x101/0x1c0 drivers/input/input.c:2520
call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747
expire_timers kernel/time/timer.c:1798 [inline]
__run_timers kernel/time/timer.c:2372 [inline]
__run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
run_timer_base kernel/time/timer.c:2393 [inline]
run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
handle_softirqs+0x286/0x870 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
check_kcov_mode kernel/kcov.c:185 [inline]
write_comp_data kernel/kcov.c:246 [inline]
__sanitizer_cov_trace_const_cmp8+0x37/0x90 kernel/kcov.c:321
__copy_present_ptes mm/memory.c:1093 [inline]
copy_present_ptes mm/memory.c:1179 [inline]
copy_pte_range mm/memory.c:1302 [inline]
copy_pmd_range+0x220d/0x7f00 mm/memory.c:1389
copy_pud_range mm/memory.c:1426 [inline]
copy_p4d_range mm/memory.c:1450 [inline]
copy_page_range+0xc14/0x1270 mm/memory.c:1538
dup_mmap+0xf4c/0x1b10 mm/mmap.c:1834
dup_mm kernel/fork.c:1489 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1541
copy_process+0x1706/0x3c00 kernel/fork.c:2181
kernel_clone+0x21e/0x840 kernel/fork.c:2609
__do_sys_clone kernel/fork.c:2750 [inline]
__se_sys_clone kernel/fork.c:2734 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
INITIAL USE at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
vt_reset_unicode+0x2b/0x160 drivers/tty/vt/keyboard.c:2187
reset_vc+0x68/0x1b0 drivers/tty/vt/vt_ioctl.c:966
vc_init+0x70/0x4a0 drivers/tty/vt/vt.c:3728
con_init+0x385/0x9c0 drivers/tty/vt/vt.c:3793
console_init+0x10e/0x430 kernel/printk/printk.c:4298
start_kernel+0x254/0x410 init/main.c:1048
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147
}
... key at: [<ffffffff8e96ee78>] kbd_event_lock+0x18/0xa0 keyboard.c:-1
-> (&tty->flow.lock){....}-{3:3} {
INITIAL USE at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline]
start_tty+0x20/0x70 drivers/tty/tty_io.c:793
n_tty_set_termios+0xa7c/0x1090 drivers/tty/n_tty.c:1858
tty_set_termios+0xda4/0x17e0 drivers/tty/tty_ioctl.c:348
set_termios+0x516/0x6c0 drivers/tty/tty_ioctl.c:516
tty_mode_ioctl+0x47e/0x740 drivers/tty/tty_ioctl.c:-1
tty_ioctl+0x9c6/0xde0 drivers/tty/tty_io.c:2801
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
}
... key at: [<ffffffff99d18ce0>] alloc_tty_struct.__key.35+0x0/0x20
... acquired at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline]
stop_tty+0x2f/0x150 drivers/tty/tty_io.c:765
kbd_keycode drivers/tty/vt/keyboard.c:1515 [inline]
kbd_event+0x2b72/0x3f70 drivers/tty/vt/keyboard.c:1534
input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541
input_pass_values+0x288/0x890 drivers/input/input.c:128
input_event_dispose+0x330/0x6b0 drivers/input/input.c:342
input_inject_event+0x1dd/0x340 drivers/input/input.c:424
evdev_write+0x2fc/0x480 drivers/input/evdev.c:528
vfs_write+0x27e/0xb30 fs/read_write.c:684
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
the dependencies between the lock to be acquired
and SOFTIRQ-irq-unsafe lock:
-> (tasklist_lock){.+.+}-{3:3} {
HARDIRQ-ON-R at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
_raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
__do_wait+0xde/0x740 kernel/exit.c:1667
do_wait+0x1f8/0x510 kernel/exit.c:1711
kernel_wait+0xab/0x170 kernel/exit.c:1887
call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
SOFTIRQ-ON-R at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
_raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
__do_wait+0xde/0x740 kernel/exit.c:1667
do_wait+0x1f8/0x510 kernel/exit.c:1711
kernel_wait+0xab/0x170 kernel/exit.c:1887
call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INITIAL USE at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
_raw_write_lock_irq+0xa2/0xf0 kernel/locking/spinlock.c:326
copy_process+0x224f/0x3c00 kernel/fork.c:2327
kernel_clone+0x21e/0x840 kernel/fork.c:2609
user_mode_thread+0xdd/0x140 kernel/fork.c:2685
rest_init+0x23/0x300 init/main.c:722
start_kernel+0x3ae/0x410 init/main.c:1111
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147
INITIAL READ USE at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
_raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
__do_wait+0xde/0x740 kernel/exit.c:1667
do_wait+0x1f8/0x510 kernel/exit.c:1711
kernel_wait+0xab/0x170 kernel/exit.c:1887
call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
}
... key at: [<ffffffff8de0c058>] tasklist_lock+0x18/0x40
... acquired at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
_raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
send_sigio+0x101/0x370 fs/fcntl.c:919
dnotify_handle_event+0x169/0x440 fs/notify/dnotify/dnotify.c:113
fsnotify_handle_event fs/notify/fsnotify.c:350 [inline]
send_to_group fs/notify/fsnotify.c:424 [inline]
fsnotify+0x1671/0x1a80 fs/notify/fsnotify.c:641
__fsnotify_parent+0x3fe/0x540 fs/notify/fsnotify.c:287
fsnotify_parent include/linux/fsnotify.h:96 [inline]
fsnotify_path include/linux/fsnotify.h:113 [inline]
fsnotify_file include/linux/fsnotify.h:127 [inline]
fsnotify_modify include/linux/fsnotify.h:433 [inline]
vfs_writev+0x77d/0x960 fs/read_write.c:1061
do_pwritev fs/read_write.c:1153 [inline]
__do_sys_pwritev2 fs/read_write.c:1211 [inline]
__se_sys_pwritev2+0x179/0x290 fs/read_write.c:1202
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> (&f_owner->lock){....}-{3:3} {
INITIAL USE at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
_raw_write_lock_irq+0xa2/0xf0 kernel/locking/spinlock.c:326
__f_setown+0x67/0x370 fs/fcntl.c:136
fcntl_dirnotify+0x3fa/0x6a0 fs/notify/dnotify/dnotify.c:369
do_fcntl+0x6d0/0x1910 fs/fcntl.c:537
__do_sys_fcntl fs/fcntl.c:589 [inline]
__se_sys_fcntl+0xc8/0x150 fs/fcntl.c:574
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
INITIAL READ USE at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
_raw_read_lock_irqsave+0xaf/0x100 kernel/locking/spinlock.c:236
send_sigio+0x38/0x370 fs/fcntl.c:905
kill_fasync_rcu fs/fcntl.c:1131 [inline]
kill_fasync+0x24d/0x4d0 fs/fcntl.c:1146
lease_break_callback+0x26/0x30 fs/locks.c:558
__break_lease+0x6a5/0x1620 fs/locks.c:1592
break_lease include/linux/filelock.h:446 [inline]
do_dentry_open+0x8b7/0x13f0 fs/open.c:956
vfs_open+0x3b/0x340 fs/open.c:1097
do_open fs/namei.c:3975 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4134
do_filp_open+0x1fa/0x410 fs/namei.c:4161
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_open fs/open.c:1460 [inline]
__se_sys_open fs/open.c:1456 [inline]
__x64_sys_open+0x11e/0x150 fs/open.c:1456
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
}
... key at: [<ffffffff99a3b880>] file_f_owner_allocate.__key+0x0/0x20
... acquired at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
_raw_read_lock_irqsave+0xaf/0x100 kernel/locking/spinlock.c:236
send_sigio+0x38/0x370 fs/fcntl.c:905
kill_fasync_rcu fs/fcntl.c:1131 [inline]
kill_fasync+0x24d/0x4d0 fs/fcntl.c:1146
lease_break_callback+0x26/0x30 fs/locks.c:558
__break_lease+0x6a5/0x1620 fs/locks.c:1592
break_lease include/linux/filelock.h:446 [inline]
do_dentry_open+0x8b7/0x13f0 fs/open.c:956
vfs_open+0x3b/0x340 fs/open.c:1097
do_open fs/namei.c:3975 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4134
do_filp_open+0x1fa/0x410 fs/namei.c:4161
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_open fs/open.c:1460 [inline]
__se_sys_open fs/open.c:1456 [inline]
__x64_sys_open+0x11e/0x150 fs/open.c:1456
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> (&new->fa_lock){....}-{3:3} {
INITIAL USE at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
_raw_write_lock_irq+0xa2/0xf0 kernel/locking/spinlock.c:326
fasync_remove_entry+0xf1/0x1c0 fs/fcntl.c:999
pipe_fasync+0xa9/0x1e0 fs/pipe.c:756
__fput+0x8a2/0xa70 fs/file_table.c:465
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
INITIAL READ USE at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
_raw_read_lock_irqsave+0xaf/0x100 kernel/locking/spinlock.c:236
kill_fasync_rcu fs/fcntl.c:1122 [inline]
kill_fasync+0x199/0x4d0 fs/fcntl.c:1146
sock_wake_async+0x137/0x160 net/socket.c:-1
sk_wake_async+0x184/0x280 include/net/sock.h:2539
mptcp_destroy_common+0x152/0x320 net/mptcp/protocol.c:3385
mptcp_disconnect+0x23d/0x700 net/mptcp/protocol.c:3197
inet_shutdown+0x1c4/0x390 net/ipv4/af_inet.c:937
__sys_shutdown_sock net/socket.c:2470 [inline]
__sys_shutdown net/socket.c:2486 [inline]
__do_sys_shutdown net/socket.c:2491 [inline]
__se_sys_shutdown net/socket.c:2489 [inline]
__x64_sys_shutdown+0x13f/0x1a0 net/socket.c:2489
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
}
... key at: [<ffffffff99a3b8a0>] fasync_insert_entry.__key+0x0/0x20
... acquired at:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
_raw_read_lock_irqsave+0xaf/0x100 kernel/locking/spinlock.c:236
kill_fasync_rcu fs/fcntl.c:1122 [inline]
kill_fasync+0x199/0x4d0 fs/fcntl.c:1146
tty_wakeup drivers/tty/tty_io.c:515 [inline]
__start_tty+0x18c/0x220 drivers/tty/tty_io.c:777
start_tty+0x2b/0x70 drivers/tty/tty_io.c:794
n_tty_set_termios+0xa7c/0x1090 drivers/tty/n_tty.c:1858
tty_set_termios+0xda4/0x17e0 drivers/tty/tty_ioctl.c:348
set_termios+0x516/0x6c0 drivers/tty/tty_ioctl.c:516
tty_mode_ioctl+0x47e/0x740 drivers/tty/tty_ioctl.c:-1
tty_ioctl+0x9c6/0xde0 drivers/tty/tty_io.c:2801
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
stack backtrace:
CPU: 0 UID: 0 PID: 28053 Comm: syz.8.7222 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_bad_irq_dependency kernel/locking/lockdep.c:2616 [inline]
check_irq_usage kernel/locking/lockdep.c:2857 [inline]
check_prev_add kernel/locking/lockdep.c:3169 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain+0x1f05/0x2140 kernel/locking/lockdep.c:3908
__lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
_raw_read_lock_irqsave+0xaf/0x100 kernel/locking/spinlock.c:236
kill_fasync_rcu fs/fcntl.c:1122 [inline]
kill_fasync+0x199/0x4d0 fs/fcntl.c:1146
tty_wakeup drivers/tty/tty_io.c:515 [inline]
__start_tty+0x18c/0x220 drivers/tty/tty_io.c:777
start_tty+0x2b/0x70 drivers/tty/tty_io.c:794
n_tty_set_termios+0xa7c/0x1090 drivers/tty/n_tty.c:1858
tty_set_termios+0xda4/0x17e0 drivers/tty/tty_ioctl.c:348
set_termios+0x516/0x6c0 drivers/tty/tty_ioctl.c:516
tty_mode_ioctl+0x47e/0x740 drivers/tty/tty_ioctl.c:-1
tty_ioctl+0x9c6/0xde0 drivers/tty/tty_io.c:2801
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f157ff8eec9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1580d69038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f15801e6090 RCX: 00007f157ff8eec9
RDX: 0000200000000140 RSI: 0000000000005402 RDI: 0000000000000004
RBP: 00007f1580011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f15801e6128 R14: 00007f15801e6090 R15: 00007f158030fa28
</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