[v6.6] possible deadlock in task_call_func
0 views
Skip to first unread message
syzbot
Aug 4, 2026, 5:12:32 PM (6 days ago) Aug 4
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: aa0e49877a2e Linux 6.6.148
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12fe5bb9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0bc3d90c30838b5
dashboard link: https://syzkaller.appspot.com/bug?extid=ad007513124ae06fa3da
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f83b390cfc1f/disk-aa0e4987.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1d4bdb338edd/vmlinux-aa0e4987.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3f57c1d51ee3/bzImage-aa0e4987.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ad0075...@syzkaller.appspotmail.com
Filesystems sync: 0.490 seconds
Freezing user space processes
------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.2.91/6103 is trying to acquire lock:
ffffffff8d1260a0 (console_owner){....}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:1995 [inline]
ffffffff8d1260a0 (console_owner){....}-{0:0}, at: vprintk_emit+0x30b/0x610 kernel/printk/printk.c:2340
but task is already holding lock:
ffff88805fd3a818 (&p->pi_lock){-.-.}-{2:2}, at: task_call_func+0x43/0x260 kernel/sched/core.c:4412
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&p->pi_lock){-.-.}-{2:2}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:523 [inline]
try_to_wake_up+0x5b/0x10e0 kernel/sched/core.c:4233
kick_pool+0x320/0x420 kernel/workqueue.c:1169
create_worker+0x61e/0x820 kernel/workqueue.c:2241
workqueue_init+0x306/0x670 kernel/workqueue.c:6802
kernel_init_freeable+0x3a7/0x560 init/main.c:1510
kernel_init+0x1d/0x1c0 init/main.c:1415
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
-> #3 (&pool->lock){-.-.}-{2:2}:
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
__queue_work+0x72f/0xfd0 kernel/workqueue.c:-1
queue_work_on+0x128/0x1f0 kernel/workqueue.c:1858
queue_work include/linux/workqueue.h:564 [inline]
rpm_suspend+0x1133/0x1b60 drivers/base/power/runtime.c:660
__pm_runtime_idle+0x12f/0x1a0 drivers/base/power/runtime.c:1102
pm_runtime_put include/linux/pm_runtime.h:454 [inline]
__device_attach+0x352/0x420 drivers/base/dd.c:1127
bus_probe_device+0x180/0x260 drivers/base/bus.c:580
device_add+0x87c/0xc40 drivers/base/core.c:3700
serial_base_port_add+0x2f6/0x430 drivers/tty/serial/serial_base_bus.c:178
serial_core_port_device_add drivers/tty/serial/serial_core.c:3377 [inline]
serial_core_register_port+0x378/0x20b0 drivers/tty/serial/serial_core.c:3418
serial8250_register_8250_port+0x15fd/0x1f40 drivers/tty/serial/8250/8250_core.c:1142
serial_pnp_probe+0x577/0x750 drivers/tty/serial/8250/8250_pnp.c:478
pnp_device_probe+0x305/0x4b0 drivers/pnp/driver.c:111
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x247/0xae0 drivers/base/dd.c:717
__driver_probe_device+0x1f5/0x390 drivers/base/dd.c:879
driver_probe_device+0x4f/0x420 drivers/base/dd.c:909
__driver_attach+0x444/0x6d0 drivers/base/dd.c:1295
bus_for_each_dev+0x235/0x2b0 drivers/base/bus.c:370
bus_add_driver+0x340/0x630 drivers/base/bus.c:723
driver_register+0x23a/0x310 drivers/base/driver.c:246
serial8250_init+0x9a/0x170 drivers/tty/serial/8250/8250_core.c:1243
do_one_initcall+0x242/0x790 init/main.c:1210
do_initcall_level+0x13d/0x1f0 init/main.c:1272
do_initcalls+0x69/0xd0 init/main.c:1288
kernel_init_freeable+0x3d9/0x560 init/main.c:1525
kernel_init+0x1d/0x1c0 init/main.c:1415
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
-> #2 (&dev->power.lock){-...}-{2:2}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
__pm_runtime_resume+0x10f/0x170 drivers/base/power/runtime.c:1169
pm_runtime_get include/linux/pm_runtime.h:402 [inline]
__uart_start+0x171/0x3e0 drivers/tty/serial/serial_core.c:148
uart_write+0x449/0x5d0 drivers/tty/serial/serial_core.c:633
process_output_block drivers/tty/n_tty.c:580 [inline]
n_tty_write+0xd3d/0x11e0 drivers/tty/n_tty.c:2395
iterate_tty_write drivers/tty/tty_io.c:1017 [inline]
file_tty_write+0x529/0x960 drivers/tty/tty_io.c:1088
call_write_iter include/linux/fs.h:2018 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x474/0x9a0 fs/read_write.c:584
ksys_write+0x151/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
-> #1 (&port_lock_key){-.-.}-{2:2}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
serial8250_console_write+0x181/0x18b0 drivers/tty/serial/8250/8250_port.c:3439
console_emit_next_record kernel/printk/printk.c:2944 [inline]
console_flush_all+0x6ad/0xcf0 kernel/printk/printk.c:3000
console_unlock+0xad/0x350 kernel/printk/printk.c:3069
vprintk_emit+0x497/0x610 kernel/printk/printk.c:2341
_printk+0xde/0x130 kernel/printk/printk.c:2366
register_console+0xb96/0xf00 kernel/printk/printk.c:3583
univ8250_console_init+0x45/0x50 drivers/tty/serial/8250/8250_core.c:717
console_init+0x17b/0x5d0 kernel/printk/printk.c:3726
start_kernel+0x2c8/0x4e0 init/main.c:982
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
copy_bootdata+0x0/0xd0 arch/x86/kernel/head64.c:536
secondary_startup_64_no_verify+0x179/0x17b
-> #0 (console_owner){....}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
console_trylock_spinning kernel/printk/printk.c:1995 [inline]
vprintk_emit+0x328/0x610 kernel/printk/printk.c:2340
_printk+0xde/0x130 kernel/printk/printk.c:2366
__report_bug lib/bug.c:195 [inline]
report_bug+0x34e/0x4f0 lib/bug.c:219
handle_bug+0xcf/0x120 arch/x86/kernel/traps.c:310
exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:345
asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:606
__set_task_frozen+0x210/0x2d0 kernel/freezer.c:133
task_call_func+0x1a2/0x260 kernel/sched/core.c:4427
__freeze_task kernel/freezer.c:144 [inline]
freeze_task+0x217/0x3a0 kernel/freezer.c:163
try_to_freeze_tasks+0x190/0x620 kernel/power/process.c:54
freeze_processes+0xc9/0x1e0 kernel/power/process.c:137
hibernate+0x121/0x400 kernel/power/hibernate.c:754
state_store+0x22f/0x290 kernel/power/main.c:710
kernfs_fop_write_iter+0x3a4/0x520 fs/kernfs/file.c:352
call_write_iter include/linux/fs.h:2018 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x474/0x9a0 fs/read_write.c:584
ksys_write+0x151/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
other info that might help us debug this:
Chain exists of:
console_owner --> &pool->lock --> &p->pi_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&p->pi_lock);
lock(&pool->lock);
lock(&p->pi_lock);
lock(console_owner);
*** DEADLOCK ***
8 locks held by syz.2.91/6103:
#0: ffff8880784a19c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
#1: ffff88807d7f4418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#2: ffff88805e3a8088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#3: ffff88801ca5c9b8 (kn->active#68){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#3: ffff88801ca5c9b8 (kn->active#68){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#4: ffffffff8cfe58a8 (system_transition_mutex){+.+.}-{3:3}, at: lock_system_sleep+0x49/0x70 kernel/power/main.c:56
#5: ffffffff8ce0a058 (tasklist_lock){.+.+}-{2:2}, at: try_to_freeze_tasks+0xe5/0x620 kernel/power/process.c:52
#6: ffffffff8d144ef8 (freezer_lock){....}-{2:2}, at: freeze_task+0x80/0x3a0 kernel/freezer.c:162
#7: ffff88805fd3a818 (&p->pi_lock){-.-.}-{2:2}, at: task_call_func+0x43/0x260 kernel/sched/core.c:4412
stack backtrace:
CPU: 1 PID: 6103 Comm: syz.2.91 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<TASK>
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2187
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
console_trylock_spinning kernel/printk/printk.c:1995 [inline]
vprintk_emit+0x328/0x610 kernel/printk/printk.c:2340
_printk+0xde/0x130 kernel/printk/printk.c:2366
__report_bug lib/bug.c:195 [inline]
report_bug+0x34e/0x4f0 lib/bug.c:219
handle_bug+0xcf/0x120 arch/x86/kernel/traps.c:310
exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:345
asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:606
RIP: 0010:__set_task_frozen+0x210/0x2d0 kernel/freezer.c:133
Code: 41 c7 06 00 80 00 00 bd 00 80 00 00 89 e8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 4c 8f 11 00 0f 0b e9 0a ff ff ff e8 40 8f 11 00 <0f> 0b eb 9d 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 14 fe ff ff 4c
RSP: 0018:ffffc90004eb7a70 EFLAGS: 00010046
RAX: ffffffff8175e240 RBX: ffff88805fd39e00 RCX: 0000000000080000
RDX: ffffc9000d5ba000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520009d6f30 R12: 0000000000000000
R13: 1ffff1100bfa73c3 R14: ffff88805fd39e18 R15: ffff88805fd3a8d8
task_call_func+0x1a2/0x260 kernel/sched/core.c:4427
__freeze_task kernel/freezer.c:144 [inline]
freeze_task+0x217/0x3a0 kernel/freezer.c:163
try_to_freeze_tasks+0x190/0x620 kernel/power/process.c:54
freeze_processes+0xc9/0x1e0 kernel/power/process.c:137
hibernate+0x121/0x400 kernel/power/hibernate.c:754
state_store+0x22f/0x290 kernel/power/main.c:710
kernfs_fop_write_iter+0x3a4/0x520 fs/kernfs/file.c:352
call_write_iter include/linux/fs.h:2018 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x474/0x9a0 fs/read_write.c:584
ksys_write+0x151/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f070099e019
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f07017a8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f0700c25fa0 RCX: 00007f070099e019
RDX: 0000000000000005 RSI: 00002000000001c0 RDI: 0000000000000003
RBP: 00007f0700a3500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0700c26038 R14: 00007f0700c25fa0 R15: 00007ffd82081438
</TASK>
WARNING: CPU: 1 PID: 6103 at kernel/freezer.c:133 __set_task_frozen+0x210/0x2d0 kernel/freezer.c:133
Modules linked in:
CPU: 1 PID: 6103 Comm: syz.2.91 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__set_task_frozen+0x210/0x2d0 kernel/freezer.c:133
Code: 41 c7 06 00 80 00 00 bd 00 80 00 00 89 e8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 4c 8f 11 00 0f 0b e9 0a ff ff ff e8 40 8f 11 00 <0f> 0b eb 9d 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 14 fe ff ff 4c
RSP: 0018:ffffc90004eb7a70 EFLAGS: 00010046
RAX: ffffffff8175e240 RBX: ffff88805fd39e00 RCX: 0000000000080000
RDX: ffffc9000d5ba000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520009d6f30 R12: 0000000000000000
R13: 1ffff1100bfa73c3 R14: ffff88805fd39e18 R15: ffff88805fd3a8d8
FS: 00007f07017a86c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 000000002ec21000 CR4: 00000000003506e0
Call Trace:
<TASK>
task_call_func+0x1a2/0x260 kernel/sched/core.c:4427
__freeze_task kernel/freezer.c:144 [inline]
freeze_task+0x217/0x3a0 kernel/freezer.c:163
try_to_freeze_tasks+0x190/0x620 kernel/power/process.c:54
freeze_processes+0xc9/0x1e0 kernel/power/process.c:137
hibernate+0x121/0x400 kernel/power/hibernate.c:754
state_store+0x22f/0x290 kernel/power/main.c:710
kernfs_fop_write_iter+0x3a4/0x520 fs/kernfs/file.c:352
call_write_iter include/linux/fs.h:2018 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x474/0x9a0 fs/read_write.c:584
ksys_write+0x151/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f070099e019
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f07017a8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f0700c25fa0 RCX: 00007f070099e019
RDX: 0000000000000005 RSI: 00002000000001c0 RDI: 0000000000000003
RBP: 00007f0700a3500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0700c26038 R14: 00007f0700c25fa0 R15: 00007ffd82081438
</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: aa0e49877a2e Linux 6.6.148
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12fe5bb9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0bc3d90c30838b5
dashboard link: https://syzkaller.appspot.com/bug?extid=ad007513124ae06fa3da
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f83b390cfc1f/disk-aa0e4987.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1d4bdb338edd/vmlinux-aa0e4987.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3f57c1d51ee3/bzImage-aa0e4987.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ad0075...@syzkaller.appspotmail.com
Filesystems sync: 0.490 seconds
Freezing user space processes
------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.2.91/6103 is trying to acquire lock:
ffffffff8d1260a0 (console_owner){....}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:1995 [inline]
ffffffff8d1260a0 (console_owner){....}-{0:0}, at: vprintk_emit+0x30b/0x610 kernel/printk/printk.c:2340
but task is already holding lock:
ffff88805fd3a818 (&p->pi_lock){-.-.}-{2:2}, at: task_call_func+0x43/0x260 kernel/sched/core.c:4412
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&p->pi_lock){-.-.}-{2:2}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:523 [inline]
try_to_wake_up+0x5b/0x10e0 kernel/sched/core.c:4233
kick_pool+0x320/0x420 kernel/workqueue.c:1169
create_worker+0x61e/0x820 kernel/workqueue.c:2241
workqueue_init+0x306/0x670 kernel/workqueue.c:6802
kernel_init_freeable+0x3a7/0x560 init/main.c:1510
kernel_init+0x1d/0x1c0 init/main.c:1415
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
-> #3 (&pool->lock){-.-.}-{2:2}:
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
__queue_work+0x72f/0xfd0 kernel/workqueue.c:-1
queue_work_on+0x128/0x1f0 kernel/workqueue.c:1858
queue_work include/linux/workqueue.h:564 [inline]
rpm_suspend+0x1133/0x1b60 drivers/base/power/runtime.c:660
__pm_runtime_idle+0x12f/0x1a0 drivers/base/power/runtime.c:1102
pm_runtime_put include/linux/pm_runtime.h:454 [inline]
__device_attach+0x352/0x420 drivers/base/dd.c:1127
bus_probe_device+0x180/0x260 drivers/base/bus.c:580
device_add+0x87c/0xc40 drivers/base/core.c:3700
serial_base_port_add+0x2f6/0x430 drivers/tty/serial/serial_base_bus.c:178
serial_core_port_device_add drivers/tty/serial/serial_core.c:3377 [inline]
serial_core_register_port+0x378/0x20b0 drivers/tty/serial/serial_core.c:3418
serial8250_register_8250_port+0x15fd/0x1f40 drivers/tty/serial/8250/8250_core.c:1142
serial_pnp_probe+0x577/0x750 drivers/tty/serial/8250/8250_pnp.c:478
pnp_device_probe+0x305/0x4b0 drivers/pnp/driver.c:111
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x247/0xae0 drivers/base/dd.c:717
__driver_probe_device+0x1f5/0x390 drivers/base/dd.c:879
driver_probe_device+0x4f/0x420 drivers/base/dd.c:909
__driver_attach+0x444/0x6d0 drivers/base/dd.c:1295
bus_for_each_dev+0x235/0x2b0 drivers/base/bus.c:370
bus_add_driver+0x340/0x630 drivers/base/bus.c:723
driver_register+0x23a/0x310 drivers/base/driver.c:246
serial8250_init+0x9a/0x170 drivers/tty/serial/8250/8250_core.c:1243
do_one_initcall+0x242/0x790 init/main.c:1210
do_initcall_level+0x13d/0x1f0 init/main.c:1272
do_initcalls+0x69/0xd0 init/main.c:1288
kernel_init_freeable+0x3d9/0x560 init/main.c:1525
kernel_init+0x1d/0x1c0 init/main.c:1415
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
-> #2 (&dev->power.lock){-...}-{2:2}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
__pm_runtime_resume+0x10f/0x170 drivers/base/power/runtime.c:1169
pm_runtime_get include/linux/pm_runtime.h:402 [inline]
__uart_start+0x171/0x3e0 drivers/tty/serial/serial_core.c:148
uart_write+0x449/0x5d0 drivers/tty/serial/serial_core.c:633
process_output_block drivers/tty/n_tty.c:580 [inline]
n_tty_write+0xd3d/0x11e0 drivers/tty/n_tty.c:2395
iterate_tty_write drivers/tty/tty_io.c:1017 [inline]
file_tty_write+0x529/0x960 drivers/tty/tty_io.c:1088
call_write_iter include/linux/fs.h:2018 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x474/0x9a0 fs/read_write.c:584
ksys_write+0x151/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
-> #1 (&port_lock_key){-.-.}-{2:2}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
serial8250_console_write+0x181/0x18b0 drivers/tty/serial/8250/8250_port.c:3439
console_emit_next_record kernel/printk/printk.c:2944 [inline]
console_flush_all+0x6ad/0xcf0 kernel/printk/printk.c:3000
console_unlock+0xad/0x350 kernel/printk/printk.c:3069
vprintk_emit+0x497/0x610 kernel/printk/printk.c:2341
_printk+0xde/0x130 kernel/printk/printk.c:2366
register_console+0xb96/0xf00 kernel/printk/printk.c:3583
univ8250_console_init+0x45/0x50 drivers/tty/serial/8250/8250_core.c:717
console_init+0x17b/0x5d0 kernel/printk/printk.c:3726
start_kernel+0x2c8/0x4e0 init/main.c:982
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
copy_bootdata+0x0/0xd0 arch/x86/kernel/head64.c:536
secondary_startup_64_no_verify+0x179/0x17b
-> #0 (console_owner){....}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
console_trylock_spinning kernel/printk/printk.c:1995 [inline]
vprintk_emit+0x328/0x610 kernel/printk/printk.c:2340
_printk+0xde/0x130 kernel/printk/printk.c:2366
__report_bug lib/bug.c:195 [inline]
report_bug+0x34e/0x4f0 lib/bug.c:219
handle_bug+0xcf/0x120 arch/x86/kernel/traps.c:310
exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:345
asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:606
__set_task_frozen+0x210/0x2d0 kernel/freezer.c:133
task_call_func+0x1a2/0x260 kernel/sched/core.c:4427
__freeze_task kernel/freezer.c:144 [inline]
freeze_task+0x217/0x3a0 kernel/freezer.c:163
try_to_freeze_tasks+0x190/0x620 kernel/power/process.c:54
freeze_processes+0xc9/0x1e0 kernel/power/process.c:137
hibernate+0x121/0x400 kernel/power/hibernate.c:754
state_store+0x22f/0x290 kernel/power/main.c:710
kernfs_fop_write_iter+0x3a4/0x520 fs/kernfs/file.c:352
call_write_iter include/linux/fs.h:2018 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x474/0x9a0 fs/read_write.c:584
ksys_write+0x151/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
other info that might help us debug this:
Chain exists of:
console_owner --> &pool->lock --> &p->pi_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&p->pi_lock);
lock(&pool->lock);
lock(&p->pi_lock);
lock(console_owner);
*** DEADLOCK ***
8 locks held by syz.2.91/6103:
#0: ffff8880784a19c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
#1: ffff88807d7f4418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#2: ffff88805e3a8088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#3: ffff88801ca5c9b8 (kn->active#68){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#3: ffff88801ca5c9b8 (kn->active#68){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#4: ffffffff8cfe58a8 (system_transition_mutex){+.+.}-{3:3}, at: lock_system_sleep+0x49/0x70 kernel/power/main.c:56
#5: ffffffff8ce0a058 (tasklist_lock){.+.+}-{2:2}, at: try_to_freeze_tasks+0xe5/0x620 kernel/power/process.c:52
#6: ffffffff8d144ef8 (freezer_lock){....}-{2:2}, at: freeze_task+0x80/0x3a0 kernel/freezer.c:162
#7: ffff88805fd3a818 (&p->pi_lock){-.-.}-{2:2}, at: task_call_func+0x43/0x260 kernel/sched/core.c:4412
stack backtrace:
CPU: 1 PID: 6103 Comm: syz.2.91 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<TASK>
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2187
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
console_trylock_spinning kernel/printk/printk.c:1995 [inline]
vprintk_emit+0x328/0x610 kernel/printk/printk.c:2340
_printk+0xde/0x130 kernel/printk/printk.c:2366
__report_bug lib/bug.c:195 [inline]
report_bug+0x34e/0x4f0 lib/bug.c:219
handle_bug+0xcf/0x120 arch/x86/kernel/traps.c:310
exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:345
asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:606
RIP: 0010:__set_task_frozen+0x210/0x2d0 kernel/freezer.c:133
Code: 41 c7 06 00 80 00 00 bd 00 80 00 00 89 e8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 4c 8f 11 00 0f 0b e9 0a ff ff ff e8 40 8f 11 00 <0f> 0b eb 9d 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 14 fe ff ff 4c
RSP: 0018:ffffc90004eb7a70 EFLAGS: 00010046
RAX: ffffffff8175e240 RBX: ffff88805fd39e00 RCX: 0000000000080000
RDX: ffffc9000d5ba000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520009d6f30 R12: 0000000000000000
R13: 1ffff1100bfa73c3 R14: ffff88805fd39e18 R15: ffff88805fd3a8d8
task_call_func+0x1a2/0x260 kernel/sched/core.c:4427
__freeze_task kernel/freezer.c:144 [inline]
freeze_task+0x217/0x3a0 kernel/freezer.c:163
try_to_freeze_tasks+0x190/0x620 kernel/power/process.c:54
freeze_processes+0xc9/0x1e0 kernel/power/process.c:137
hibernate+0x121/0x400 kernel/power/hibernate.c:754
state_store+0x22f/0x290 kernel/power/main.c:710
kernfs_fop_write_iter+0x3a4/0x520 fs/kernfs/file.c:352
call_write_iter include/linux/fs.h:2018 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x474/0x9a0 fs/read_write.c:584
ksys_write+0x151/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f070099e019
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f07017a8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f0700c25fa0 RCX: 00007f070099e019
RDX: 0000000000000005 RSI: 00002000000001c0 RDI: 0000000000000003
RBP: 00007f0700a3500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0700c26038 R14: 00007f0700c25fa0 R15: 00007ffd82081438
</TASK>
WARNING: CPU: 1 PID: 6103 at kernel/freezer.c:133 __set_task_frozen+0x210/0x2d0 kernel/freezer.c:133
Modules linked in:
CPU: 1 PID: 6103 Comm: syz.2.91 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__set_task_frozen+0x210/0x2d0 kernel/freezer.c:133
Code: 41 c7 06 00 80 00 00 bd 00 80 00 00 89 e8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 4c 8f 11 00 0f 0b e9 0a ff ff ff e8 40 8f 11 00 <0f> 0b eb 9d 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 14 fe ff ff 4c
RSP: 0018:ffffc90004eb7a70 EFLAGS: 00010046
RAX: ffffffff8175e240 RBX: ffff88805fd39e00 RCX: 0000000000080000
RDX: ffffc9000d5ba000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520009d6f30 R12: 0000000000000000
R13: 1ffff1100bfa73c3 R14: ffff88805fd39e18 R15: ffff88805fd3a8d8
FS: 00007f07017a86c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 000000002ec21000 CR4: 00000000003506e0
Call Trace:
<TASK>
task_call_func+0x1a2/0x260 kernel/sched/core.c:4427
__freeze_task kernel/freezer.c:144 [inline]
freeze_task+0x217/0x3a0 kernel/freezer.c:163
try_to_freeze_tasks+0x190/0x620 kernel/power/process.c:54
freeze_processes+0xc9/0x1e0 kernel/power/process.c:137
hibernate+0x121/0x400 kernel/power/hibernate.c:754
state_store+0x22f/0x290 kernel/power/main.c:710
kernfs_fop_write_iter+0x3a4/0x520 fs/kernfs/file.c:352
call_write_iter include/linux/fs.h:2018 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x474/0x9a0 fs/read_write.c:584
ksys_write+0x151/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f070099e019
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f07017a8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f0700c25fa0 RCX: 00007f070099e019
RDX: 0000000000000005 RSI: 00002000000001c0 RDI: 0000000000000003
RBP: 00007f0700a3500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0700c26038 R14: 00007f0700c25fa0 R15: 00007ffd82081438
</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