syzbot

INFO: task kworker/u8:6:755 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:6    state:D stack:24960 pid:755   tgid:755   ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1295/0x67a0 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7283
 schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121
 __debugfs_file_removed fs/debugfs/inode.c:751 [inline]
 remove_one+0x312/0x420 fs/debugfs/inode.c:758
 __simple_recursive_removal+0x148/0x5c0 fs/libfs.c:624
 debugfs_remove+0x5d/0x80 fs/debugfs/inode.c:781
 nsim_dev_health_exit+0x3b/0xe0 drivers/net/netdevsim/health.c:227
 nsim_dev_reload_destroy+0x144/0x4a0 drivers/net/netdevsim/dev.c:1788
 nsim_dev_reload_down+0x66/0xd0 drivers/net/netdevsim/dev.c:1038
 devlink_reload+0x1ae/0x7a0 net/devlink/dev.c:462
 devlink_pernet_pre_exit+0x247/0x370 net/devlink/core.c:558
 ops_pre_exit_list net/core/net_namespace.c:161 [inline]
 ops_undo_list+0x187/0xab0 net/core/net_namespace.c:234
 cleanup_net+0x499/0x920 net/core/net_namespace.c:702
 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
 process_scheduled_works kernel/workqueue.c:3385 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task syz-executor:9272 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:23976 pid:9272  tgid:9272  ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1295/0x67a0 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7283
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:820
 device_lock include/linux/device.h:1040 [inline]
 device_del+0xa0/0x9b0 drivers/base/core.c:3857
 device_unregister+0x1d/0xe0 drivers/base/core.c:3936
 nsim_bus_dev_del drivers/net/netdevsim/bus.c:491 [inline]
 del_device_store+0x346/0x480 drivers/net/netdevsim/bus.c:244
 bus_attr_store+0x74/0xb0 drivers/base/bus.c:172
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142
 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:352
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6ac/0x1070 fs/read_write.c:688
 ksys_write+0x12a/0x250 fs/read_write.c:740
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9361b5d60e
RSP: 002b:00007ffca211b408 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055557b6b4500 RCX: 00007f9361b5d60e
RDX: 0000000000000001 RSI: 00007ffca211b490 RDI: 0000000000000005
RBP: 00007f9361c335ec R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffca211b490 R14: 00007f9362944620 R15: 0000000000000003
 </TASK>
INFO: task syz.0.3242:9279 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.3242      state:D stack:28312 pid:9279  tgid:9279  ppid:8263   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1295/0x67a0 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7283
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:820
 devlink_health_report+0x66c/0xb20 net/devlink/health.c:680
 nsim_dev_health_break_write+0x166/0x210 drivers/net/netdevsim/health.c:162
 full_proxy_write+0x135/0x1a0 fs/debugfs/file.c:388
 vfs_write+0x2aa/0x1070 fs/read_write.c:686
 ksys_write+0x12a/0x250 fs/read_write.c:740
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f557459cdd9
RSP: 002b:00007ffff8c55ca8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5574815fa0 RCX: 00007f557459cdd9
RDX: 00000000000001e1 RSI: 0000200000000080 RDI: 0000000000000004
RBP: 00007f5574632d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5574815fac R14: 00007f5574815fa0 R15: 00007f5574815fa0
 </TASK>
INFO: task syz.3.3266:9310 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.3266      state:D stack:28440 pid:9310  tgid:9310  ppid:5776   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1295/0x67a0 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7283
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
 rwsem_down_read_slowpath+0x5af/0xb40 kernel/locking/rwsem.c:1114
 __down_read_common kernel/locking/rwsem.c:1291 [inline]
 __down_read kernel/locking/rwsem.c:1304 [inline]
 down_read+0xed/0x450 kernel/locking/rwsem.c:1570
 inode_lock_shared include/linux/fs.h:1044 [inline]
 open_last_lookups fs/namei.c:4610 [inline]
 path_openat+0xa16/0x31a0 fs/namei.c:4855
 do_file_open+0x20e/0x430 fs/namei.c:4887
 do_sys_openat2+0x10d/0x1e0 fs/open.c:1364
 do_sys_open fs/open.c:1370 [inline]
 __do_sys_openat fs/open.c:1386 [inline]
 __se_sys_openat fs/open.c:1381 [inline]
 __x64_sys_openat+0x12d/0x210 fs/open.c:1381
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbdf779cdd9
RSP: 002b:00007fff96365178 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fbdf7a15fa0 RCX: 00007fbdf779cdd9
RDX: 0000000000048081 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007fbdf7832d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbdf7a15fac R14: 00007fbdf7a15fa0 R15: 00007fbdf7a15fa0
 </TASK>
INFO: task syz.1.3265:9311 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.3265      state:D stack:27752 pid:9311  tgid:9311  ppid:8766   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1295/0x67a0 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7283
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
 rwsem_down_read_slowpath+0x5af/0xb40 kernel/locking/rwsem.c:1114
 __down_read_common kernel/locking/rwsem.c:1291 [inline]
 __down_read kernel/locking/rwsem.c:1304 [inline]
 down_read+0xed/0x450 kernel/locking/rwsem.c:1570
 inode_lock_shared include/linux/fs.h:1044 [inline]
 open_last_lookups fs/namei.c:4610 [inline]
 path_openat+0xa16/0x31a0 fs/namei.c:4855
 do_file_open+0x20e/0x430 fs/namei.c:4887
 do_sys_openat2+0x10d/0x1e0 fs/open.c:1364
 do_sys_open fs/open.c:1370 [inline]
 __do_sys_openat fs/open.c:1386 [inline]
 __se_sys_openat fs/open.c:1381 [inline]
 __x64_sys_openat+0x12d/0x210 fs/open.c:1381
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7eff9539cdd9
RSP: 002b:00007ffc25189bb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007eff95615fa0 RCX: 00007eff9539cdd9
RDX: 0000000000048081 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007eff95432d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007eff95615fac R14: 00007eff95615fa0 R15: 00007eff95615fa0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e7e52e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8e7e52e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e7e52e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
6 locks held by kworker/u8:6/755:
 #0: ffff88801c6ae140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277
 #1: ffffc9000457fd08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278
 #2: ffffffff905f6368 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:673
 #3: ffff888035350128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #3: ffff888035350128 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline]
 #3: ffff888035350128 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x19e/0x370 net/devlink/core.c:555
 #4: ffff888034d3f258 (&devlink->lock_key#4){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline]
 #4: ffff888034d3f258 (&devlink->lock_key#4){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline]
 #4: ffff888034d3f258 (&devlink->lock_key#4){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x1b4/0x370 net/devlink/core.c:555
 #5: ffff88805bde71b0 (&sb->s_type->i_mutex_key#9/2){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline]
 #5: ffff88805bde71b0 (&sb->s_type->i_mutex_key#9/2){+.+.}-{4:4}, at: __simple_recursive_removal+0xe0/0x5c0 fs/libfs.c:620
3 locks held by kworker/u8:7/1054:
 #0: ffff8880b853b3e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x140 kernel/sched/core.c:652
 #1: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:225 [inline]
 #1: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2f15/0x67a0 kernel/sched/core.c:7183
 #2: ffff88805c4f0780 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6645 [inline]
 #2: ffff88805c4f0780 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0x92/0x570 net/wireless/core.c:499
3 locks held by klogd/4982:
 #0: ffff8880b853b3e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x140 kernel/sched/core.c:652
 #1: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:225 [inline]
 #1: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2f15/0x67a0 kernel/sched/core.c:7183
 #2: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:225 [inline]
 #2: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2f15/0x67a0 kernel/sched/core.c:7183
2 locks held by getty/5379:
 #0: ffff888033b6e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211
5 locks held by syz-executor/9272:
 #0: ffff8880349f0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
 #1: ffff888079084080 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
 #3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
 #4: ffff888035350128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #4: ffff888035350128 (&dev->mutex){....}-{4:4}, at: device_del+0xa0/0x9b0 drivers/base/core.c:3857
2 locks held by syz.0.3242/9279:
 #0: ffff888020292410 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
 #1: ffff888034d3f258 (&devlink->lock_key#4){+.+.}-{4:4}, at: devlink_health_report+0x66c/0xb20 net/devlink/health.c:680
2 locks held by syz.3.3266/9310:
 #0: ffff888020292410 (sb_writers#8){.+.+}-{0:0}, at: open_last_lookups fs/namei.c:4600 [inline]
 #0: ffff888020292410 (sb_writers#8){.+.+}-{0:0}, at: path_openat+0x9b1/0x31a0 fs/namei.c:4855
 #1: ffff88805bde71b0 (&sb->s_type->i_mutex_key#17){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1044 [inline]
 #1: ffff88805bde71b0 (&sb->s_type->i_mutex_key#17){++++}-{4:4}, at: open_last_lookups fs/namei.c:4610 [inline]
 #1: ffff88805bde71b0 (&sb->s_type->i_mutex_key#17){++++}-{4:4}, at: path_openat+0xa16/0x31a0 fs/namei.c:4855
2 locks held by syz.1.3265/9311:
 #0: ffff888020292410 (sb_writers#8){.+.+}-{0:0}, at: open_last_lookups fs/namei.c:4600 [inline]
 #0: ffff888020292410 (sb_writers#8){.+.+}-{0:0}, at: path_openat+0x9b1/0x31a0 fs/namei.c:4855
 #1: ffff88805bde71b0 (&sb->s_type->i_mutex_key#17){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1044 [inline]
 #1: ffff88805bde71b0 (&sb->s_type->i_mutex_key#17){++++}-{4:4}, at: open_last_lookups fs/namei.c:4610 [inline]
 #1: ffff88805bde71b0 (&sb->s_type->i_mutex_key#17){++++}-{4:4}, at: path_openat+0xa16/0x31a0 fs/namei.c:4855
4 locks held by syz-executor/9332:
 #0: ffff8880349f0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
 #1: ffff88802a878c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
 #3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/9351:
 #0: ffff8880349f0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
 #1: ffff8880267f9480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
 #3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/9353:
 #0: ffff8880349f0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
 #1: ffff88807ed97c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
 #3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/9387:
 #0: ffff8880349f0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
 #1: ffff88806931b480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
 #3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/9412:
 #0: ffff8880349f0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
 #1: ffff8880723a3c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
 #3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/9432:
 #0: ffff8880349f0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
 #1: ffff888036e93c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
 #3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/9434:
 #0: ffff8880349f0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
 #1: ffff88807aa2f080 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
 #3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/9471:
 #0: ffff8880349f0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
 #1: ffff888057818c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
 #3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/9497:
 #0: ffff8880349f0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
 #1: ffff888032d6dc80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
 #3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/9517:
 #0: ffff8880349f0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
 #1: ffff88807f52d080 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
 #3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/9519:
 #0: ffff8880349f0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
 #1: ffff888033721c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff88802a7d4e18 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
 #3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xcb1/0x1030 kernel/hung_task.c:561
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: e6 94 02 e9 c3 42 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 83 8f 23 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df0 EFLAGS: 00000242
RAX: 0000000000119fd3 RBX: ffff88801e680000 RCX: ffffffff8b880095
RDX: 0000000000000000 RSI: ffffffff8df1c469 RDI: ffffffff8c1c2800
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170a67b5
R10: ffff8880b8533dab R11: 0000000000000000 R12: 0000000000000001
R13: ffffed1003cd0000 R14: 0000000000000001 R15: ffffffff90d7dc50
FS:  0000000000000000(0000) GS:ffff888124477000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9c9e688e9c CR3: 000000000e596000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
 default_idle+0x9/0x10 arch/x86/kernel/process.c:767
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x464/0x590 kernel/sched/idle.c:352
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451
 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x148
 </TASK>