[syzbot] INFO: task hung in rfkill_global_led_trigger_worker (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: e01d50cbd6ee Merge tag 'vfio-v6.1-rc6' of https://github.c..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=136f6401880000
kernel config: https://syzkaller.appspot.com/x/.config?x=47b0b2ecc119b39f
dashboard link: https://syzkaller.appspot.com/bug?extid=2e39bc6569d281acbcfb
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17e85d35880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1579ac01880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b48e4d485e7e/disk-e01d50cb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/dc9ba558e055/vmlinux-e01d50cb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b766d9815123/bzImage-e01d50cb.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2e39bc...@syzkaller.appspotmail.com

INFO: task kworker/0:6:4120 blocked for more than 143 seconds.
Not tainted 6.1.0-rc5-syzkaller-00008-ge01d50cbd6ee #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:6 state:D stack:24024 pid:4120 ppid:2 flags:0x00004000
Workqueue: events rfkill_global_led_trigger_worker
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5191 [inline]
__schedule+0x8c9/0xd70 kernel/sched/core.c:6503
schedule+0xcb/0x190 kernel/sched/core.c:6579
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6638
__mutex_lock_common+0xe4f/0x26e0 kernel/locking/mutex.c:679
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
rfkill_global_led_trigger_worker+0x1b/0xf0 net/rfkill/core.c:181
process_one_work+0x877/0xdb0 kernel/workqueue.c:2289
worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
kthread+0x266/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>
INFO: task syz-executor145:4505 blocked for more than 143 seconds.
Not tainted 6.1.0-rc5-syzkaller-00008-ge01d50cbd6ee #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor145 state:D stack:21896 pid:4505 ppid:3645 flags:0x00004002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5191 [inline]
__schedule+0x8c9/0xd70 kernel/sched/core.c:6503
schedule+0xcb/0x190 kernel/sched/core.c:6579
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6638
__mutex_lock_common+0xe4f/0x26e0 kernel/locking/mutex.c:679
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
rfkill_unregister+0xcb/0x220 net/rfkill/core.c:1130
nfc_unregister_device+0xba/0x290 net/nfc/core.c:1167
virtual_ncidev_close+0x55/0x90 drivers/nfc/virtual_ncidev.c:166
__fput+0x3ba/0x880 fs/file_table.c:320
task_work_run+0x243/0x300 kernel/task_work.c:179
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0x664/0x2070 kernel/exit.c:820
do_group_exit+0x1fd/0x2b0 kernel/exit.c:950
__do_sys_exit_group kernel/exit.c:961 [inline]
__se_sys_exit_group kernel/exit.c:959 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:959
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc8e3d92af9
RSP: 002b:00007fff2cfab0b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fc8e3e06330 RCX: 00007fc8e3d92af9
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000246 R12: 00007fc8e3e06330
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
</TASK>
INFO: task syz-executor145:4514 blocked for more than 143 seconds.
Not tainted 6.1.0-rc5-syzkaller-00008-ge01d50cbd6ee #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor145 state:D stack:23816 pid:4514 ppid:3640 flags:0x00004002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5191 [inline]
__schedule+0x8c9/0xd70 kernel/sched/core.c:6503
schedule+0xcb/0x190 kernel/sched/core.c:6579
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6638
__mutex_lock_common+0xe4f/0x26e0 kernel/locking/mutex.c:679
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
rfkill_fop_release+0x49/0x230 net/rfkill/core.c:1312
__fput+0x3ba/0x880 fs/file_table.c:320
task_work_run+0x243/0x300 kernel/task_work.c:179
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0x664/0x2070 kernel/exit.c:820
do_group_exit+0x1fd/0x2b0 kernel/exit.c:950
__do_sys_exit_group kernel/exit.c:961 [inline]
__se_sys_exit_group kernel/exit.c:959 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:959
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc8e3d92af9
RSP: 002b:00007fff2cfab0b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fc8e3e06330 RCX: 00007fc8e3d92af9
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000246 R12: 00007fc8e3e06330
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
</TASK>
INFO: task syz-executor145:4516 blocked for more than 144 seconds.
Not tainted 6.1.0-rc5-syzkaller-00008-ge01d50cbd6ee #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor145 state:D stack:23096 pid:4516 ppid:3647 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5191 [inline]
__schedule+0x8c9/0xd70 kernel/sched/core.c:6503
schedule+0xcb/0x190 kernel/sched/core.c:6579
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6638
__mutex_lock_common+0xe4f/0x26e0 kernel/locking/mutex.c:679
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
device_lock include/linux/device.h:835 [inline]
nfc_dev_down+0x33/0x260 net/nfc/core.c:143
nfc_rfkill_set_block+0x28/0xc0 net/nfc/core.c:179
rfkill_set_block+0x1e7/0x430 net/rfkill/core.c:345
rfkill_fop_write+0x5db/0x790 net/rfkill/core.c:1286
vfs_write+0x303/0xc50 fs/read_write.c:582
ksys_write+0x177/0x2a0 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc8e3d93e69
RSP: 002b:00007fff2cfab108 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007fc8e3d93e69
RDX: 0000000000000008 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000d60b
R13: 00007fff2cfab11c R14: 00007fff2cfab130 R15: 00007fff2cfab120
</TASK>
INFO: task syz-executor145:4517 blocked for more than 144 seconds.
Not tainted 6.1.0-rc5-syzkaller-00008-ge01d50cbd6ee #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor145 state:D stack:23816 pid:4517 ppid:3643 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5191 [inline]
__schedule+0x8c9/0xd70 kernel/sched/core.c:6503
schedule+0xcb/0x190 kernel/sched/core.c:6579
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6638
__mutex_lock_common+0xe4f/0x26e0 kernel/locking/mutex.c:679
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
misc_open+0x57/0x3c0 drivers/char/misc.c:107
chrdev_open+0x53b/0x5f0 fs/char_dev.c:414
do_dentry_open+0x85f/0x11b0 fs/open.c:882
do_open fs/namei.c:3557 [inline]
path_openat+0x25fc/0x2df0 fs/namei.c:3713
do_filp_open+0x264/0x4f0 fs/namei.c:3740
do_sys_openat2+0x124/0x4e0 fs/open.c:1310
do_sys_open fs/open.c:1326 [inline]
__do_sys_openat fs/open.c:1342 [inline]
__se_sys_openat fs/open.c:1337 [inline]
__x64_sys_openat+0x243/0x290 fs/open.c:1337
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc8e3d93e69
RSP: 002b:00007fff2cfab108 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007fc8e3d93e69
RDX: 0000000000000002 RSI: 0000000020002100 RDI: ffffffffffffff9c
RBP: 0000000000000000 R08: 00007fff2cfaab80 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000d60c
R13: 00007fff2cfab11c R14: 00007fff2cfab130 R15: 00007fff2cfab120
</TASK>
INFO: task syz-executor145:4518 blocked for more than 144 seconds.
Not tainted 6.1.0-rc5-syzkaller-00008-ge01d50cbd6ee #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor145 state:D stack:23816 pid:4518 ppid:3639 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5191 [inline]
__schedule+0x8c9/0xd70 kernel/sched/core.c:6503
schedule+0xcb/0x190 kernel/sched/core.c:6579
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6638
__mutex_lock_common+0xe4f/0x26e0 kernel/locking/mutex.c:679
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
misc_open+0x57/0x3c0 drivers/char/misc.c:107
chrdev_open+0x53b/0x5f0 fs/char_dev.c:414
do_dentry_open+0x85f/0x11b0 fs/open.c:882
do_open fs/namei.c:3557 [inline]
path_openat+0x25fc/0x2df0 fs/namei.c:3713
do_filp_open+0x264/0x4f0 fs/namei.c:3740
do_sys_openat2+0x124/0x4e0 fs/open.c:1310
do_sys_open fs/open.c:1326 [inline]
__do_sys_openat fs/open.c:1342 [inline]
__se_sys_openat fs/open.c:1337 [inline]
__x64_sys_openat+0x243/0x290 fs/open.c:1337
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc8e3d93e69
RSP: 002b:00007fff2cfab108 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007fc8e3d93e69
RDX: 0000000000000002 RSI: 0000000020002100 RDI: ffffffffffffff9c
RBP: 0000000000000000 R08: 00007fff2cfaab80 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000d60c
R13: 00007fff2cfab11c R14: 00007fff2cfab130 R15: 00007fff2cfab120
</TASK>
INFO: task syz-executor145:4519 blocked for more than 144 seconds.
Not tainted 6.1.0-rc5-syzkaller-00008-ge01d50cbd6ee #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor145 state:D stack:23816 pid:4519 ppid:3642 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5191 [inline]
__schedule+0x8c9/0xd70 kernel/sched/core.c:6503
schedule+0xcb/0x190 kernel/sched/core.c:6579
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6638
__mutex_lock_common+0xe4f/0x26e0 kernel/locking/mutex.c:679
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
rfkill_fop_open+0x12f/0x690 net/rfkill/core.c:1163
misc_open+0x346/0x3c0 drivers/char/misc.c:143
chrdev_open+0x53b/0x5f0 fs/char_dev.c:414
do_dentry_open+0x85f/0x11b0 fs/open.c:882
do_open fs/namei.c:3557 [inline]
path_openat+0x25fc/0x2df0 fs/namei.c:3713
do_filp_open+0x264/0x4f0 fs/namei.c:3740
do_sys_openat2+0x124/0x4e0 fs/open.c:1310
do_sys_open fs/open.c:1326 [inline]
__do_sys_openat fs/open.c:1342 [inline]
__se_sys_openat fs/open.c:1337 [inline]
__x64_sys_openat+0x243/0x290 fs/open.c:1337
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc8e3d93e69
RSP: 002b:00007fff2cfab108 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007fc8e3d93e69
RDX: 0000000000022002 RSI: 0000000020000080 RDI: ffffffffffffff9c
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000d64b
R13: 00007fff2cfab11c R14: 00007fff2cfab130 R15: 00007fff2cfab120
</TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8d327330 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8d327b30 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507
1 lock held by khungtaskd/28:
#0: ffffffff8d327160 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3308:
#0: ffff888145009098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x53b/0x1650 drivers/tty/n_tty.c:2177
3 locks held by kworker/0:6/4120:
#0: ffff888012864d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7f2/0xdb0
#1: ffffc90004d0fd00 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_one_work+0x831/0xdb0 kernel/workqueue.c:2264
#2: ffffffff8e787b08 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_global_led_trigger_worker+0x1b/0xf0 net/rfkill/core.c:181
2 locks held by syz-executor145/4505:
#0: ffff88807268e100 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline]
#0: ffff88807268e100 (&dev->mutex){....}-{3:3}, at: nfc_unregister_device+0x87/0x290 net/nfc/core.c:1165
#1: ffffffff8e787b08 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_unregister+0xcb/0x220 net/rfkill/core.c:1130
1 lock held by syz-executor145/4514:
#0: ffffffff8e787b08 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_release+0x49/0x230 net/rfkill/core.c:1312
2 locks held by syz-executor145/4516:
#0: ffffffff8e787b08 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0x1b3/0x790 net/rfkill/core.c:1278
#1: ffff88807268e100 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline]
#1: ffff88807268e100 (&dev->mutex){....}-{3:3}, at: nfc_dev_down+0x33/0x260 net/nfc/core.c:143
1 lock held by syz-executor145/4517:
#0: ffffffff8da8f368 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x57/0x3c0 drivers/char/misc.c:107
1 lock held by syz-executor145/4518:
#0: ffffffff8da8f368 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x57/0x3c0 drivers/char/misc.c:107
2 locks held by syz-executor145/4519:
#0: ffffffff8da8f368 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x57/0x3c0 drivers/char/misc.c:107
#1: ffffffff8e787b08 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_open+0x12f/0x690 net/rfkill/core.c:1163

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.0-rc5-syzkaller-00008-ge01d50cbd6ee #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
nmi_cpu_backtrace+0x46f/0x4f0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1ba/0x420 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xcf5/0xd40 kernel/hung_task.c:377
kthread+0x266/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 9 Comm: kworker/u4:0 Not tainted 6.1.0-rc5-syzkaller-00008-ge01d50cbd6ee #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:235 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x4/0xa0 kernel/kcov.c:311
Code: f0 48 83 c8 08 48 c7 04 01 05 00 00 00 48 89 f0 48 83 c8 10 48 89 14 01 48 83 ce 18 4c 89 0c 31 4c 89 44 f9 20 c3 4c 8b 04 24 <65> 48 8b 14 25 40 6f 02 00 65 8b 0d 24 d2 77 7e f7 c1 00 01 ff 00
RSP: 0018:ffffc900000e7a78 EFLAGS: 00000246
RAX: ffffffff920114a0 RBX: 0000000000000000 RCX: ffffffff8cd12a50
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff81b5a436 R09: fffff5200001cf3d
R10: fffff5200001cf3d R11: 1ffff9200001cf3c R12: 0000000000000020
R13: ffffffff8cd12a30 R14: dffffc0000000000 R15: 1ffffffff19a254b
FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f4c9bd9990 CR3: 000000000d08e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__jump_label_update+0xa6/0x3b0
static_key_disable_cpuslocked+0xc8/0x1b0 kernel/jump_label.c:207
static_key_disable+0x16/0x20 kernel/jump_label.c:215
toggle_allocation_gate+0x3b8/0x450 mm/kfence/core.c:814
process_one_work+0x877/0xdb0 kernel/workqueue.c:2289
worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
kthread+0x266/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>


---
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[Hillf Danton]

On 15 Nov 2022 08:56:42 -0800

No deadlock was reported for syz-executor145/4505 and syz-executor145/4516.
Why?

Hillf

[Hillf Danton]

On 15 Nov 2022 08:56:42 -0800

> syzbot found the following issue on:
>
> HEAD commit: e01d50cbd6ee Merge tag 'vfio-v6.1-rc6' of https://github.c..
> git tree: upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=136f6401880000
> kernel config: https://syzkaller.appspot.com/x/.config?x=47b0b2ecc119b39f
> dashboard link: https://syzkaller.appspot.com/bug?extid=2e39bc6569d281acbcfb

> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17e85d35880000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1579ac01880000

Destroy rfkill without device lock held.

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git e01d50cbd6ee

--- x/net/nfc/core.c
+++ a/net/nfc/core.c
@@ -1163,13 +1163,16 @@ void nfc_unregister_device(struct nfc_de
"was removed\n", dev_name(&dev->dev));

device_lock(&dev->dev);
+ dev->shutting_down = true;
if (dev->rfkill) {
- rfkill_unregister(dev->rfkill);
- rfkill_destroy(dev->rfkill);
+ struct rfkill *rfkill = dev->rfkill;
dev->rfkill = NULL;
- }
- dev->shutting_down = true;
- device_unlock(&dev->dev);
+
+ device_unlock(&dev->dev);
+ rfkill_unregister(rfkill);
+ rfkill_destroy(rfkill);
+ } else
+ device_unlock(&dev->dev);

if (dev->ops->check_presence) {
del_timer_sync(&dev->check_pres_timer);
--

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
INFO: rcu detected stall in corrupted

rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { P4112 } 2628 jiffies s: 2845 root: 0x0/T
rcu: blocking rcu_node structures (internal RCU debug):


Tested on:

commit: e01d50cb Merge tag 'vfio-v6.1-rc6' of https://github.c..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=16ef649e880000

kernel config: https://syzkaller.appspot.com/x/.config?x=47b0b2ecc119b39f
dashboard link: https://syzkaller.appspot.com/bug?extid=2e39bc6569d281acbcfb

compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=14b645be880000

[Hillf Danton]

On 15 Nov 2022 08:56:42 -0800

> syzbot found the following issue on:
>
> HEAD commit: e01d50cbd6ee Merge tag 'vfio-v6.1-rc6' of https://github.c..
> git tree: upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=136f6401880000
> kernel config: https://syzkaller.appspot.com/x/.config?x=47b0b2ecc119b39f
> dashboard link: https://syzkaller.appspot.com/bug?extid=2e39bc6569d281acbcfb

> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17e85d35880000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1579ac01880000

Destroy rfkill without device lock held.

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git 9e4ce762f0e7

[Tetsuo Handa]

On 2022/11/16 13:17, Hillf Danton wrote:
> No deadlock was reported for syz-executor145/4505 and syz-executor145/4516.
> Why?

Lockdep should be able to report this real deadlock case. But unfortunately,

>> INFO: task syz-executor145:4505 blocked for more than 143 seconds.
>> Not tainted 6.1.0-rc5-syzkaller-00008-ge01d50cbd6ee #0
>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>> task:syz-executor145 state:D stack:21896 pid:4505 ppid:3645 flags:0x00004002
>>

>> 2 locks held by syz-executor145/4505:
>> #0: ffff88807268e100 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline]
>> #0: ffff88807268e100 (&dev->mutex){....}-{3:3}, at: nfc_unregister_device+0x87/0x290 net/nfc/core.c:1165
>> #1: ffffffff8e787b08 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_unregister+0xcb/0x220 net/rfkill/core.c:1130
>>

>> INFO: task syz-executor145:4516 blocked for more than 144 seconds.
>> Not tainted 6.1.0-rc5-syzkaller-00008-ge01d50cbd6ee #0
>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>> task:syz-executor145 state:D stack:23096 pid:4516 ppid:3647 flags:0x00004004
>>

>> 2 locks held by syz-executor145/4516:
>> #0: ffffffff8e787b08 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0x1b3/0x790 net/rfkill/core.c:1278
>> #1: ffff88807268e100 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline]
>> #1: ffff88807268e100 (&dev->mutex){....}-{3:3}, at: nfc_dev_down+0x33/0x260 net/nfc/core.c:143

device_initialize() hides dev->mutex from lockdep tests; explained at
https://groups.google.com/g/syzkaller-bugs/c/Uj9LqEUCwac/m/BhdTjWhNAQAJ .

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to checkout kernel repo https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git on commit 9e4ce762f0e7: failed to run ["git" "checkout" "9e4ce762f0e7"]: exit status 1
error: pathspec '9e4ce762f0e7' did not match any file(s) known to git



Tested on:

commit: [unknown
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git 9e4ce762f0e7

dashboard link: https://syzkaller.appspot.com/bug?extid=2e39bc6569d281acbcfb
compiler:

patch: https://syzkaller.appspot.com/x/patch.diff?x=141f1031880000