syzbot

INFO: task syz.4.92:6456 blocked for more than 142 seconds.
      Not tainted 6.12.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.92        state:D stack:25744 pid:6456  tgid:6436  ppid:5839   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5328 [inline]
 __schedule+0x17fa/0x4bd0 kernel/sched/core.c:6693
 __schedule_loop kernel/sched/core.c:6770 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6785
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6842
 rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176
 __down_write_common kernel/locking/rwsem.c:1304 [inline]
 __down_write kernel/locking/rwsem.c:1313 [inline]
 down_write_nested+0x1e0/0x220 kernel/locking/rwsem.c:1694
 inode_lock_nested include/linux/fs.h:850 [inline]
 vfs_rename+0x658/0xf00 fs/namei.c:4976
 do_renameat2+0xd94/0x13f0 fs/namei.c:5170
 __do_sys_rename fs/namei.c:5217 [inline]
 __se_sys_rename fs/namei.c:5215 [inline]
 __x64_sys_rename+0x82/0x90 fs/namei.c:5215
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f82d7d7e719
RSP: 002b:00007f82d8ad6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007f82d7f36058 RCX: 00007f82d7d7e719
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000020000580
RBP: 00007f82d7df175e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f82d7f36058 R15: 00007fffcb707db8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720
3 locks held by kworker/u8:5/190:
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90002edfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90002edfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcc1908 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276
3 locks held by kworker/u8:6/750:
 #0: ffff888030bd3948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff888030bd3948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc9000323fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc9000323fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcc1908 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4196
5 locks held by kworker/u8:9/3548:
 #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc9000c68fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc9000c68fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcb4dd0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:580
 #3: ffffffff8fcc1908 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe9/0xaa0 net/core/dev.c:11938
 #4: ffffffff8e93d478 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline]
 #4: ffffffff8e93d478 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976
4 locks held by udevd/5206:
 #0: ffff88805df8b8b8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb4/0xd70 fs/seq_file.c:182
 #1: ffff88802bfa6088 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154
 #2: ffff8880649e2878 (kn->active#5){.+.+}-{0:0}, at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155
 #3: ffff88807419b0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #3: ffff88807419b0e8 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17d/0x340 drivers/base/core.c:2736
1 lock held by dhcpcd/5500:
 #0: ffffffff8fcc1908 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x2ce/0x1aa0 net/ipv4/devinet.c:1112
2 locks held by getty/5589:
 #0: ffff88814d9680a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
5 locks held by syz.4.92/6456:
 #0: ffff888058ad6420 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515
 #1: ffff888058ad6730 (&type->s_vfs_rename_key#2){+.+.}-{3:3}, at: lock_rename fs/namei.c:3165 [inline]
 #1: ffff888058ad6730 (&type->s_vfs_rename_key#2){+.+.}-{3:3}, at: do_renameat2+0x5cf/0x13f0 fs/namei.c:5105
 #2: ffff8880713d8f80 (&sb->s_type->i_mutex_key#26/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:850 [inline]
 #2: ffff8880713d8f80 (&sb->s_type->i_mutex_key#26/1){+.+.}-{3:3}, at: lock_two_directories+0x145/0x220 fs/namei.c:3131
 #3: ffff8880713d82a0 (&sb->s_type->i_mutex_key#26/5){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:850 [inline]
 #3: ffff8880713d82a0 (&sb->s_type->i_mutex_key#26/5){+.+.}-{3:3}, at: lock_two_directories+0x16f/0x220 fs/namei.c:3132
 #4: ffff8880713d82a0 (&sb->s_type->i_mutex_key#26/2){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:850 [inline]
 #4: ffff8880713d82a0 (&sb->s_type->i_mutex_key#26/2){+.+.}-{3:3}, at: vfs_rename+0x658/0xf00 fs/namei.c:4976
1 lock held by syz-executor/9225:
 #0: ffffffff8fcc1908 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fcc1908 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6672
7 locks held by syz-executor/9426:
 #0: ffff888035b64420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888035b64420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff88805ab37c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff888027f76698 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f55f6a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: new_device_store+0x1b4/0x890 drivers/net/netdevsim/bus.c:166
 #4: ffff88807419b0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #4: ffff88807419b0e8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1005
 #5: ffff88807419c250 (&devlink->lock_key#11){+.+.}-{3:3}, at: nsim_drv_probe+0xcb/0xb80 drivers/net/netdevsim/dev.c:1537
 #6: ffffffff8fcc1908 (rtnl_mutex){+.+.}-{3:3}, at: register_nexthop_notifier+0x84/0x290 net/ipv4/nexthop.c:3885
4 locks held by syz-executor/9427:
 #0: ffff888035b64420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888035b64420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff88807b545888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff888027f76788 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f55f6a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
1 lock held by syz-executor/9593:
 #0: ffffffff8fcc1908 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x48c/0x2400 drivers/net/tun.c:3121
3 locks held by syz.8.453/9602:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xff4/0x1040 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 53 Comm: kworker/u8:3 Not tainted 6.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:mark_lock+0x15/0x360 kernel/locking/lockdep.c:4686
Code: 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 48 83 ec 10 49 89 f7 48 89 3c 24 <49> bd 00 00 00 00 00 fc ff df 83 fa 08 75 27 49 8d 5f 20 48 89 d8
RSP: 0018:ffffc90000be76b8 EFLAGS: 00000086
RAX: 000000000004075b RBX: ffff888021eda958 RCX: ffffffff8170cf4a
RDX: 0000000000000002 RSI: ffff888021eda958 RDI: ffff888021ed9e00
RBP: ffffc90000be77a8 R08: ffffffff9429b8ef R09: 1ffffffff285371d
R10: dffffc0000000000 R11: fffffbfff285371e R12: ffff888021eda978
R13: 0000000000000003 R14: ffff888021eda8d8 R15: ffff888021eda958
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4dcf1ff000 CR3: 000000000e734000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 mark_held_locks kernel/locking/lockdep.c:4321 [inline]
 __trace_hardirqs_on_caller kernel/locking/lockdep.c:4339 [inline]
 lockdep_hardirqs_on_prepare+0x282/0x780 kernel/locking/lockdep.c:4406
 trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:61
 crng_make_state+0x4db/0xa80 drivers/char/random.c:393
 _get_random_bytes+0xd7/0x2c0 drivers/char/random.c:406
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:775 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
 nsim_dev_trap_report_work+0x622/0xab0 drivers/net/netdevsim/dev.c:851
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>