INFO: task kworker/u8:9:1163 blocked for more than 143 seconds.
      Tainted: G          I         syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:9    state:D stack:22216 pid:1163  tgid:1163  ppid:2      task_flags:0x4208160 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7058
 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121
 __debugfs_file_removed fs/debugfs/inode.c:769 [inline]
 remove_one+0x312/0x420 fs/debugfs/inode.c:776
 __simple_recursive_removal+0x158/0x610 fs/libfs.c:631
 debugfs_remove+0x5d/0x80 fs/debugfs/inode.c:799
 nsim_dev_health_exit+0x3b/0xe0 drivers/net/netdevsim/health.c:227
 nsim_dev_reload_destroy+0x144/0x4d0 drivers/net/netdevsim/dev.c:1710
 nsim_dev_reload_down+0x6e/0xd0 drivers/net/netdevsim/dev.c:983
 devlink_reload+0x1a1/0x7c0 net/devlink/dev.c:461
 devlink_pernet_pre_exit+0x1a0/0x2b0 net/devlink/core.c:509
 ops_pre_exit_list net/core/net_namespace.c:160 [inline]
 ops_undo_list+0x187/0xab0 net/core/net_namespace.c:233
 cleanup_net+0x408/0x890 net/core/net_namespace.c:682
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task syz.0.1456:9591 blocked for more than 143 seconds.
      Tainted: G          I         syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1456      state:D stack:27160 pid:9591  tgid:9589  ppid:5876   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760
 devlink_health_report+0x3ba/0x9c0 net/devlink/health.c:627
 nsim_dev_health_break_write+0x166/0x210 drivers/net/netdevsim/health.c:162
 full_proxy_write+0x12e/0x1a0 fs/debugfs/file.c:388
 do_loop_readv_writev fs/read_write.c:850 [inline]
 do_loop_readv_writev fs/read_write.c:835 [inline]
 vfs_writev+0x5df/0xde0 fs/read_write.c:1059
 do_writev+0x132/0x340 fs/read_write.c:1103
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0876f8ebe9
RSP: 002b:00007f0877e6b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f08771c5fa0 RCX: 00007f0876f8ebe9
RDX: 000000000000000b RSI: 0000200000000000 RDI: 0000000000000000
RBP: 00007f0877011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f08771c6038 R14: 00007f08771c5fa0 R15: 00007ffd772ee528
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e5c10e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e5c10e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e5c10e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
6 locks held by kworker/u8:9/1163:
 #0: ffff88801c6fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
 #1: ffffc9000449fd10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
 #2: ffffffff90371510 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x890 net/core/net_namespace.c:658
 #3: ffff888075d250e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #3: ffff888075d250e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline]
 #3: ffff888075d250e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x12c/0x2b0 net/devlink/core.c:506
 #4: ffff888075d26250 (&devlink->lock_key){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline]
 #4: ffff888075d26250 (&devlink->lock_key){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline]
 #4: ffff888075d26250 (&devlink->lock_key){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x136/0x2b0 net/devlink/core.c:506
 #5: ffff88805b8295a8 (&sb->s_type->i_mutex_key#3/2){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:914 [inline]
 #5: ffff88805b8295a8 (&sb->s_type->i_mutex_key#3/2){+.+.}-{4:4}, at: __simple_recursive_removal+0x354/0x610 fs/libfs.c:627
2 locks held by kworker/u9:1/5186:
 #0: ffff88802651b948 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
 #1: ffffc9000ed07d10 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
2 locks held by getty/9467:
 #0: ffff8880313930a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000359b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
2 locks held by syz.0.1456/9591:
 #0: ffff888140e8a428 (sb_writers#8){.+.+}-{0:0}, at: do_writev+0x132/0x340 fs/read_write.c:1103
 #1: ffff888075d26250 (&devlink->lock_key){+.+.}-{4:4}, at: devlink_health_report+0x3ba/0x9c0 net/devlink/health.c:627
1 lock held by syz.2.3006/13499:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G          I         syzkaller #0 PREEMPT(full) 
Tainted: [I]=FIRMWARE_WORKAROUND
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
 watchdog+0xf0e/0x1260 kernel/hung_task.c:491
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 59 Comm: kworker/u8:4 Tainted: G          I         syzkaller #0 PREEMPT(full) 
Tainted: [I]=FIRMWARE_WORKAROUND
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: kvfree_rcu_reclaim kfree_rcu_work
RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:412
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <c3> cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 e9 db 1e 98 f5 cc
RSP: 0018:ffffc9000210faa8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880e2e76c00 RCX: ffffffff816c85aa
RDX: ffff88801d7a8000 RSI: ffff888062e76c00 RDI: 0000000000000006
RBP: ffff888062e76c00 R08: 0000000000000006 R09: ffff888062e76c00
R10: ffff8880e2e76c00 R11: 000000000000012a R12: 0000000000000000
R13: ffff888062e76c00 R14: 000000000000012a R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881246c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe3d24ed58 CR3: 0000000075bbe000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __phys_addr+0x2a/0x180 arch/x86/mm/physaddr.c:20
 virt_to_folio include/linux/mm.h:1180 [inline]
 virt_to_slab mm/slab.h:187 [inline]
 build_detached_freelist mm/slub.c:5227 [inline]
 kmem_cache_free_bulk.part.0+0x146/0x7f0 mm/slub.c:5279
 kfree_bulk include/linux/slab.h:794 [inline]
 kvfree_rcu_bulk+0x1b7/0x1e0 mm/slab_common.c:1516
 kfree_rcu_work+0x124/0x1a0 mm/slab_common.c:1594
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>