[v6.6] INFO: task hung in remove_one
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syzbot
1:11 AM (16 hours ago) 1:11 AM
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: a1153c0deb44 Linux 6.6.147
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13521e32580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0bc3d90c30838b5
dashboard link: https://syzkaller.appspot.com/bug?extid=2c544ba85ab929d6af8b
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/9f646bfa1b52/disk-a1153c0d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a2aec2e8f0fd/vmlinux-a1153c0d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a7abe1f87405/bzImage-a1153c0d.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2c544b...@syzkaller.appspotmail.com
INFO: task syz-executor:23254 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22344 pid:23254 ppid:1 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_timeout+0xc1/0x2d0 kernel/time/timer.c:2144
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common kernel/sched/completion.c:116 [inline]
wait_for_common kernel/sched/completion.c:127 [inline]
wait_for_completion+0x2c6/0x5a0 kernel/sched/completion.c:148
__debugfs_file_removed fs/debugfs/inode.c:748 [inline]
remove_one+0xe8/0x130 fs/debugfs/inode.c:754
simple_recursive_removal+0x613/0x7e0 fs/libfs.c:633
debugfs_remove+0x56/0x70 fs/debugfs/inode.c:777
nsim_dev_debugfs_exit drivers/net/netdevsim/dev.c:367 [inline]
nsim_drv_remove+0xc0/0x170 drivers/net/netdevsim/dev.c:1680
device_remove drivers/base/dd.c:626 [inline]
__device_release_driver drivers/base/dd.c:1351 [inline]
device_release_driver_internal+0x408/0x6f0 drivers/base/dd.c:1374
bus_remove_device+0x43b/0x520 drivers/base/bus.c:624
device_del+0x51f/0x910 drivers/base/core.c:3889
device_unregister+0x20/0xc0 drivers/base/core.c:3930
nsim_bus_dev_del drivers/net/netdevsim/bus.c:310 [inline]
del_device_store+0x2b6/0x370 drivers/net/netdevsim/bus.c:219
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: 0033:0x7fbfba75e84e
RSP: 002b:00007ffcb171a7a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00005555899fd500 RCX: 00007fbfba75e84e
RDX: 0000000000000001 RSI: 00007ffcb171a830 RDI: 0000000000000005
RBP: 00007fbfba83588f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffcb171a830 R14: 00007fbfbb554620 R15: 0000000000000003
</TASK>
INFO: task syz.3.5096:23329 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.5096 state:D stack:27912 pid:23329 ppid:21717 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
nsim_bus_dev_max_vfs_write+0x214/0x380 drivers/net/netdevsim/dev.c:275
full_proxy_write+0x110/0x1c0 fs/debugfs/file.c:244
vfs_write+0x299/0x9a0 fs/read_write.c:582
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: 0033:0x7fa34a79e019
RSP: 002b:00007fa34b605028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa34aa25fa0 RCX: 00007fa34a79e019
RDX: 0000000000000001 RSI: 0000200000000180 RDI: 0000000000000003
RBP: 00007fa34a83500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa34aa26038 R14: 00007fa34aa25fa0 R15: 00007ffef5a8a438
</TASK>
INFO: task syz.3.5096:23332 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.5096 state:D stack:26280 pid:23332 ppid:21717 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
__fdget_pos+0x2a3/0x330 fs/file.c:1040
fdget_pos include/linux/file.h:75 [inline]
ksys_write+0x7b/0x260 fs/read_write.c:628
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: 0033:0x7fa34a79e019
RSP: 002b:00007fa34b5e4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa34aa26090 RCX: 00007fa34a79e019
RDX: 0000000000001006 RSI: 0000200000000340 RDI: 0000000000000003
RBP: 00007fa34a83500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa34aa26128 R14: 00007fa34aa26090 R15: 00007ffef5a8a438
</TASK>
Showing all locks held in the system:
1 lock held by ksoftirqd/0/16:
1 lock held by khungtaskd/29:
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:2/42:
2 locks held by kworker/0:2/173:
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#1: ffffc90002f27d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90002f27d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
2 locks held by getty/5532:
#0: ffff8880315720a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
2 locks held by kworker/u4:7/18486:
1 lock held by syz.5.3976/19094:
#0: ffffffff8e3d6b08 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8e3d6b08 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3514
2 locks held by syz.4.4265/20171:
#0: ffffffff8e3d6b08 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8e3d6b08 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3514
#1: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#1: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
7 locks held by syz-executor/23254:
#0: ffff88807e596418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88805ce82088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
#4: ffff8881412aa130 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1094 [inline]
#4: ffff8881412aa130 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1174 [inline]
#4: ffff8881412aa130 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa7/0x6f0 drivers/base/dd.c:1371
#5: ffff8881412ac250 (&devlink->lock_key#8){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x170 drivers/net/netdevsim/dev.c:1676
#6: ffff88805d3369e0 (&sb->s_type->i_mutex_key#3/2){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
#6: ffff88805d3369e0 (&sb->s_type->i_mutex_key#3/2){+.+.}-{3:3}, at: simple_recursive_removal+0x319/0x7e0 fs/libfs.c:625
3 locks held by syz.3.5096/23329:
#0: ffff88802e61eac8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
#1: ffff888142a6a418 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#2: ffff8881412ac250 (&devlink->lock_key#8){+.+.}-{3:3}, at: nsim_bus_dev_max_vfs_write+0x214/0x380 drivers/net/netdevsim/dev.c:275
1 lock held by syz.3.5096/23332:
#0: ffff88802e61eac8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
4 locks held by syz-executor/23413:
#0: ffff88807e596418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff888059e48088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/23454:
#0: ffff88807e596418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88814cf15c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/23469:
#0: ffff88807e596418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff888087223c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/23484:
#0: ffff88807e596418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88808b7abc88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/23500:
#0: ffff88807e596418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff888034934488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd 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
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf59/0xfa0 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 42 Comm: kworker/u4:2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: bat_events batadv_nc_worker
RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline]
RIP: 0010:lock_acquire+0x1a2/0x420 kernel/locking/lockdep.c:5756
Code: c1 4c 89 ef 8b 74 24 1c 89 da 48 8b 4c 24 20 4c 8b 44 24 30 6a 00 6a 00 6a 00 ff 75 10 ff 74 24 48 e8 c2 03 00 00 48 83 c4 28 <48> c7 c7 60 dd ca 8a e8 e2 54 24 09 b8 ff ff ff ff 65 0f c1 05 5d
RSP: 0018:ffffc90000b2fa40 EFLAGS: 00000092
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911eb500
RBP: ffffc90000b2fb48 R08: dffffc0000000000 R09: 1ffffffff223d6a0
R10: dffffc0000000000 R11: fffffbfff223d6a1 R12: 1ffff92000165f54
R13: ffffffff8d131da0 R14: 0000000000000246 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f3b304ca78 CR3: 000000000cf32000 CR4: 00000000003506e0
Call Trace:
<TASK>
rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
rcu_read_lock include/linux/rcupdate.h:786 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0xef/0x600 net/batman-adv/network-coding.c:719
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</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.
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If the report is already addressed, let syzbot know by replying with:
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If you want to overwrite report's subsystems, reply with:
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If the report is a duplicate of another one, reply with:
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If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: a1153c0deb44 Linux 6.6.147
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13521e32580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0bc3d90c30838b5
dashboard link: https://syzkaller.appspot.com/bug?extid=2c544ba85ab929d6af8b
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/9f646bfa1b52/disk-a1153c0d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a2aec2e8f0fd/vmlinux-a1153c0d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a7abe1f87405/bzImage-a1153c0d.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2c544b...@syzkaller.appspotmail.com
INFO: task syz-executor:23254 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22344 pid:23254 ppid:1 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_timeout+0xc1/0x2d0 kernel/time/timer.c:2144
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common kernel/sched/completion.c:116 [inline]
wait_for_common kernel/sched/completion.c:127 [inline]
wait_for_completion+0x2c6/0x5a0 kernel/sched/completion.c:148
__debugfs_file_removed fs/debugfs/inode.c:748 [inline]
remove_one+0xe8/0x130 fs/debugfs/inode.c:754
simple_recursive_removal+0x613/0x7e0 fs/libfs.c:633
debugfs_remove+0x56/0x70 fs/debugfs/inode.c:777
nsim_dev_debugfs_exit drivers/net/netdevsim/dev.c:367 [inline]
nsim_drv_remove+0xc0/0x170 drivers/net/netdevsim/dev.c:1680
device_remove drivers/base/dd.c:626 [inline]
__device_release_driver drivers/base/dd.c:1351 [inline]
device_release_driver_internal+0x408/0x6f0 drivers/base/dd.c:1374
bus_remove_device+0x43b/0x520 drivers/base/bus.c:624
device_del+0x51f/0x910 drivers/base/core.c:3889
device_unregister+0x20/0xc0 drivers/base/core.c:3930
nsim_bus_dev_del drivers/net/netdevsim/bus.c:310 [inline]
del_device_store+0x2b6/0x370 drivers/net/netdevsim/bus.c:219
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: 0033:0x7fbfba75e84e
RSP: 002b:00007ffcb171a7a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00005555899fd500 RCX: 00007fbfba75e84e
RDX: 0000000000000001 RSI: 00007ffcb171a830 RDI: 0000000000000005
RBP: 00007fbfba83588f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffcb171a830 R14: 00007fbfbb554620 R15: 0000000000000003
</TASK>
INFO: task syz.3.5096:23329 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.5096 state:D stack:27912 pid:23329 ppid:21717 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
nsim_bus_dev_max_vfs_write+0x214/0x380 drivers/net/netdevsim/dev.c:275
full_proxy_write+0x110/0x1c0 fs/debugfs/file.c:244
vfs_write+0x299/0x9a0 fs/read_write.c:582
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: 0033:0x7fa34a79e019
RSP: 002b:00007fa34b605028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa34aa25fa0 RCX: 00007fa34a79e019
RDX: 0000000000000001 RSI: 0000200000000180 RDI: 0000000000000003
RBP: 00007fa34a83500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa34aa26038 R14: 00007fa34aa25fa0 R15: 00007ffef5a8a438
</TASK>
INFO: task syz.3.5096:23332 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.5096 state:D stack:26280 pid:23332 ppid:21717 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
__fdget_pos+0x2a3/0x330 fs/file.c:1040
fdget_pos include/linux/file.h:75 [inline]
ksys_write+0x7b/0x260 fs/read_write.c:628
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: 0033:0x7fa34a79e019
RSP: 002b:00007fa34b5e4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa34aa26090 RCX: 00007fa34a79e019
RDX: 0000000000001006 RSI: 0000200000000340 RDI: 0000000000000003
RBP: 00007fa34a83500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa34aa26128 R14: 00007fa34aa26090 R15: 00007ffef5a8a438
</TASK>
Showing all locks held in the system:
1 lock held by ksoftirqd/0/16:
1 lock held by khungtaskd/29:
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:2/42:
2 locks held by kworker/0:2/173:
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#1: ffffc90002f27d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90002f27d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
2 locks held by getty/5532:
#0: ffff8880315720a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
2 locks held by kworker/u4:7/18486:
1 lock held by syz.5.3976/19094:
#0: ffffffff8e3d6b08 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8e3d6b08 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3514
2 locks held by syz.4.4265/20171:
#0: ffffffff8e3d6b08 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8e3d6b08 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3514
#1: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#1: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
7 locks held by syz-executor/23254:
#0: ffff88807e596418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88805ce82088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
#4: ffff8881412aa130 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1094 [inline]
#4: ffff8881412aa130 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1174 [inline]
#4: ffff8881412aa130 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa7/0x6f0 drivers/base/dd.c:1371
#5: ffff8881412ac250 (&devlink->lock_key#8){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x170 drivers/net/netdevsim/dev.c:1676
#6: ffff88805d3369e0 (&sb->s_type->i_mutex_key#3/2){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
#6: ffff88805d3369e0 (&sb->s_type->i_mutex_key#3/2){+.+.}-{3:3}, at: simple_recursive_removal+0x319/0x7e0 fs/libfs.c:625
3 locks held by syz.3.5096/23329:
#0: ffff88802e61eac8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
#1: ffff888142a6a418 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#2: ffff8881412ac250 (&devlink->lock_key#8){+.+.}-{3:3}, at: nsim_bus_dev_max_vfs_write+0x214/0x380 drivers/net/netdevsim/dev.c:275
1 lock held by syz.3.5096/23332:
#0: ffff88802e61eac8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
4 locks held by syz-executor/23413:
#0: ffff88807e596418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff888059e48088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/23454:
#0: ffff88807e596418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88814cf15c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/23469:
#0: ffff88807e596418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff888087223c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/23484:
#0: ffff88807e596418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88808b7abc88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/23500:
#0: ffff88807e596418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff888034934488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880249498c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd 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
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf59/0xfa0 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 42 Comm: kworker/u4:2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: bat_events batadv_nc_worker
RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline]
RIP: 0010:lock_acquire+0x1a2/0x420 kernel/locking/lockdep.c:5756
Code: c1 4c 89 ef 8b 74 24 1c 89 da 48 8b 4c 24 20 4c 8b 44 24 30 6a 00 6a 00 6a 00 ff 75 10 ff 74 24 48 e8 c2 03 00 00 48 83 c4 28 <48> c7 c7 60 dd ca 8a e8 e2 54 24 09 b8 ff ff ff ff 65 0f c1 05 5d
RSP: 0018:ffffc90000b2fa40 EFLAGS: 00000092
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911eb500
RBP: ffffc90000b2fb48 R08: dffffc0000000000 R09: 1ffffffff223d6a0
R10: dffffc0000000000 R11: fffffbfff223d6a1 R12: 1ffff92000165f54
R13: ffffffff8d131da0 R14: 0000000000000246 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f3b304ca78 CR3: 000000000cf32000 CR4: 00000000003506e0
Call Trace:
<TASK>
rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
rcu_read_lock include/linux/rcupdate.h:786 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0xef/0x600 net/batman-adv/network-coding.c:719
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
---
This report is generated by a bot. It may contain errors.
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If you want to undo deduplication, reply with:
#syz undup
syzbot
4:26 AM (13 hours ago) 4:26 AM
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:
HEAD commit: a1153c0deb44 Linux 6.6.147
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1158f4c6580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9f646bfa1b52/disk-a1153c0d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a2aec2e8f0fd/vmlinux-a1153c0d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a7abe1f87405/bzImage-a1153c0d.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2c544b...@syzkaller.appspotmail.com
INFO: task syz-executor:9360 blocked for more than 143 seconds.
RIP: 0033:0x7fe10f95e84e
RSP: 002b:00007fff8a1719e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055556f326500 RCX: 00007fe10f95e84e
RDX: 0000000000000001 RSI: 00007fff8a171a70 RDI: 0000000000000005
RBP: 00007fe10fa3588f R08: 0000000000000000 R09: 0000000000000000
</TASK>
INFO: task syz.1.3288:9445 blocked for more than 143 seconds.
RSP: 002b:00007ffd664bb418 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f82b4425fa0 RCX: 00007f82b419e019
</TASK>
INFO: task syz.3.3289:9446 blocked for more than 144 seconds.
RSP: 002b:00007ffc5847d798 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f7362625fa0 RCX: 00007f736239e019
</TASK>
INFO: task syz.2.3290:9447 blocked for more than 144 seconds.
RSP: 002b:00007ffcf3d9f058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f2580e25fa0 RCX: 00007f2580b9e019
1 lock held by syslogd/5120:
#0: ffff8880b8e3c298 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff888023d92c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#4: ffff88814666f130 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1174 [inline]
#4: ffff88814666f130 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa7/0x6f0 drivers/base/dd.c:1371
#5: ffff88814666b250 (&devlink->lock_key#4){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x170 drivers/net/netdevsim/dev.c:1676
#6: ffff88805d533400 (&sb->s_type->i_mutex_key#3/2){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
#6: ffff88805d533400 (&sb->s_type->i_mutex_key#3/2){+.+.}-{3:3}, at: simple_recursive_removal+0x319/0x7e0 fs/libfs.c:625
2 locks held by syz.1.3288/9445:
#0: ffff888142274418 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88814666b250 (&devlink->lock_key#4){+.+.}-{3:3}, at: nsim_bus_dev_max_vfs_write+0x214/0x380 drivers/net/netdevsim/dev.c:275
2 locks held by syz.3.3289/9446:
#0: ffff888142274418 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88814666b250 (&devlink->lock_key#4){+.+.}-{3:3}, at: nsim_bus_dev_max_vfs_write+0x214/0x380 drivers/net/netdevsim/dev.c:275
2 locks held by syz.2.3290/9447:
#0: ffff888142274418 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88814666b250 (&devlink->lock_key#4){+.+.}-{3:3}, at: nsim_bus_dev_max_vfs_write+0x214/0x380 drivers/net/netdevsim/dev.c:275
4 locks held by syz-executor/9468:
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff888141e43488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff888144edec88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff8880302a9088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88805cc6b488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88802c9be888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88805f5a1888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff8880302c6088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88805d204088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff888056f10888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff888056f02888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88805becf888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
Code: 2f 97 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 06 02 00 00 83 3d 33 e0 c5 15 00 74 36 45 31 ff 49 83 c7 60 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 04 a8 76 00 b8 01 00 00 00 45 85
RSP: 0018:ffffc90000117940 EFLAGS: 00000802
RAX: 1ffffffff2176352 RBX: ffff88801be55a00 RCX: ffffffff81694414
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911eb5e8
RBP: 0000000000000006 R08: ffffffff911eb5ef R09: 1ffffffff223d6bd
R10: dffffc0000000000 R11: fffffbfff223d6be R12: 0000000000000040
R13: dffffc0000000000 R14: ffff88801be564e0 R15: ffffffff90bb1a90
Call Trace:
<TASK>
mark_held_locks kernel/locking/lockdep.c:4274 [inline]
__trace_hardirqs_on_caller kernel/locking/lockdep.c:4300 [inline]
lockdep_hardirqs_on_prepare+0x384/0x7d0 kernel/locking/lockdep.c:4359
trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:61
__local_bh_enable_ip+0x13a/0x1c0 kernel/softirq.c:411
spin_unlock_bh include/linux/spinlock.h:396 [inline]
batadv_nc_purge_paths+0x300/0x3a0 net/batman-adv/network-coding.c:471
batadv_nc_worker+0x363/0x600 net/batman-adv/network-coding.c:722
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
HEAD commit: a1153c0deb44 Linux 6.6.147
git tree: linux-6.6.y
kernel config: https://syzkaller.appspot.com/x/.config?x=f0bc3d90c30838b5
dashboard link: https://syzkaller.appspot.com/bug?extid=2c544ba85ab929d6af8b
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=171d8db9580000
dashboard link: https://syzkaller.appspot.com/bug?extid=2c544ba85ab929d6af8b
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9f646bfa1b52/disk-a1153c0d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a2aec2e8f0fd/vmlinux-a1153c0d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a7abe1f87405/bzImage-a1153c0d.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2c544b...@syzkaller.appspotmail.com
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22344 pid:9360 ppid:1 flags:0x00004006
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
RSP: 002b:00007fff8a1719e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055556f326500 RCX: 00007fe10f95e84e
RDX: 0000000000000001 RSI: 00007fff8a171a70 RDI: 0000000000000005
RBP: 00007fe10fa3588f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff8a171a70 R14: 00007fe110754620 R15: 0000000000000003
</TASK>
INFO: task syz.1.3288:9445 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.3288 state:D stack:27560 pid:9445 ppid:8314 flags:0x00004004
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
nsim_bus_dev_max_vfs_write+0x214/0x380 drivers/net/netdevsim/dev.c:275
full_proxy_write+0x110/0x1c0 fs/debugfs/file.c:244
vfs_write+0x299/0x9a0 fs/read_write.c:582
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: 0033:0x7f82b419e019
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
nsim_bus_dev_max_vfs_write+0x214/0x380 drivers/net/netdevsim/dev.c:275
full_proxy_write+0x110/0x1c0 fs/debugfs/file.c:244
vfs_write+0x299/0x9a0 fs/read_write.c:582
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
RSP: 002b:00007ffd664bb418 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f82b4425fa0 RCX: 00007f82b419e019
RDX: 0000000000000001 RSI: 0000200000000180 RDI: 0000000000000003
RBP: 00007f82b423500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f82b4425fac R14: 00007f82b4425fa0 R15: 00007f82b4425fa0
</TASK>
INFO: task syz.3.3289:9446 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.3289 state:D stack:27560 pid:9446 ppid:5904 flags:0x00004004
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
nsim_bus_dev_max_vfs_write+0x214/0x380 drivers/net/netdevsim/dev.c:275
full_proxy_write+0x110/0x1c0 fs/debugfs/file.c:244
vfs_write+0x299/0x9a0 fs/read_write.c:582
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: 0033:0x7f736239e019
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
nsim_bus_dev_max_vfs_write+0x214/0x380 drivers/net/netdevsim/dev.c:275
full_proxy_write+0x110/0x1c0 fs/debugfs/file.c:244
vfs_write+0x299/0x9a0 fs/read_write.c:582
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
RSP: 002b:00007ffc5847d798 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f7362625fa0 RCX: 00007f736239e019
RDX: 0000000000000001 RSI: 0000200000000180 RDI: 0000000000000003
RBP: 00007f736243500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7362625fac R14: 00007f7362625fa0 R15: 00007f7362625fa0
</TASK>
INFO: task syz.2.3290:9447 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.3290 state:D stack:27560 pid:9447 ppid:8827 flags:0x00004004
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
nsim_bus_dev_max_vfs_write+0x214/0x380 drivers/net/netdevsim/dev.c:275
full_proxy_write+0x110/0x1c0 fs/debugfs/file.c:244
vfs_write+0x299/0x9a0 fs/read_write.c:582
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: 0033:0x7f2580b9e019
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
nsim_bus_dev_max_vfs_write+0x214/0x380 drivers/net/netdevsim/dev.c:275
full_proxy_write+0x110/0x1c0 fs/debugfs/file.c:244
vfs_write+0x299/0x9a0 fs/read_write.c:582
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
RSP: 002b:00007ffcf3d9f058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f2580e25fa0 RCX: 00007f2580b9e019
RDX: 0000000000000001 RSI: 0000200000000180 RDI: 0000000000000003
RBP: 00007f2580c3500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2580e25fac R14: 00007f2580e25fa0 R15: 00007f2580e25fa0
</TASK>
Showing all locks held in the system:
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/u4:7/2935:
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
1 lock held by syslogd/5120:
#0: ffff8880b8e3c298 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559
2 locks held by getty/5532:
#0: ffff88814c6020a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
7 locks held by syz-executor/9360:
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff888023d92c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
#4: ffff88814666f130 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1094 [inline]
#4: ffff88814666f130 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1174 [inline]
#4: ffff88814666f130 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa7/0x6f0 drivers/base/dd.c:1371
#5: ffff88814666b250 (&devlink->lock_key#4){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x170 drivers/net/netdevsim/dev.c:1676
#6: ffff88805d533400 (&sb->s_type->i_mutex_key#3/2){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
#6: ffff88805d533400 (&sb->s_type->i_mutex_key#3/2){+.+.}-{3:3}, at: simple_recursive_removal+0x319/0x7e0 fs/libfs.c:625
2 locks held by syz.1.3288/9445:
#0: ffff888142274418 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88814666b250 (&devlink->lock_key#4){+.+.}-{3:3}, at: nsim_bus_dev_max_vfs_write+0x214/0x380 drivers/net/netdevsim/dev.c:275
2 locks held by syz.3.3289/9446:
#0: ffff888142274418 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88814666b250 (&devlink->lock_key#4){+.+.}-{3:3}, at: nsim_bus_dev_max_vfs_write+0x214/0x380 drivers/net/netdevsim/dev.c:275
2 locks held by syz.2.3290/9447:
#0: ffff888142274418 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88814666b250 (&devlink->lock_key#4){+.+.}-{3:3}, at: nsim_bus_dev_max_vfs_write+0x214/0x380 drivers/net/netdevsim/dev.c:275
4 locks held by syz-executor/9468:
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff888141e43488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/9470:
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff888144edec88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/9473:
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff8880302a9088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/9496:
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88805cc6b488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/9513:
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88802c9be888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/9517:
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88805f5a1888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/9518:
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff8880302c6088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/9545:
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88805d204088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/9564:
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff888056f10888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/9567:
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff888056f02888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/9569:
#0: ffff88802d1b8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88805becf888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888024bbb4e0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8dcb73a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd 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
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf59/0xfa0 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 12 Comm: kworker/u4:1 Not tainted syzkaller #0
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd 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
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf59/0xfa0 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: bat_events batadv_nc_worker
RIP: 0010:mark_lock+0xdd/0x320 kernel/locking/lockdep.c:4656
Workqueue: bat_events batadv_nc_worker
Code: 2f 97 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 06 02 00 00 83 3d 33 e0 c5 15 00 74 36 45 31 ff 49 83 c7 60 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 04 a8 76 00 b8 01 00 00 00 45 85
RSP: 0018:ffffc90000117940 EFLAGS: 00000802
RAX: 1ffffffff2176352 RBX: ffff88801be55a00 RCX: ffffffff81694414
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911eb5e8
RBP: 0000000000000006 R08: ffffffff911eb5ef R09: 1ffffffff223d6bd
R10: dffffc0000000000 R11: fffffbfff223d6be R12: 0000000000000040
R13: dffffc0000000000 R14: ffff88801be564e0 R15: ffffffff90bb1a90
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564c499a0a38 CR3: 000000000cf32000 CR4: 00000000003506e0
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Call Trace:
<TASK>
mark_held_locks kernel/locking/lockdep.c:4274 [inline]
__trace_hardirqs_on_caller kernel/locking/lockdep.c:4300 [inline]
lockdep_hardirqs_on_prepare+0x384/0x7d0 kernel/locking/lockdep.c:4359
trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:61
__local_bh_enable_ip+0x13a/0x1c0 kernel/softirq.c:411
spin_unlock_bh include/linux/spinlock.h:396 [inline]
batadv_nc_purge_paths+0x300/0x3a0 net/batman-adv/network-coding.c:471
batadv_nc_worker+0x363/0x600 net/batman-adv/network-coding.c:722
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
---
If you want syzbot to run the reproducer, reply with:
process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
---
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
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