syzbot


INFO: task hung in fqdir_free_fn

Status: auto-obsoleted due to no activity on 2025/02/05 05:14
Subsystems: net
[Documentation on labels]
First crash: 282d, last: 172d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: task hung in fqdir_free_fn 1 278d 278d 0/3 auto-obsoleted due to no activity on 2024/11/01 18:36

Sample crash report:
INFO: task kworker/1:8:5927 blocked for more than 143 seconds.
      Not tainted 6.12.0-rc6-syzkaller-00099-g7758b206117d #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:8     state:D stack:18392 pid:5927  tgid:5927  ppid:2      flags:0x00004000
Workqueue: events fqdir_free_fn
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5328 [inline]
 __schedule+0x184f/0x4c30 kernel/sched/core.c:6690
 __schedule_loop kernel/sched/core.c:6767 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6782
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6839
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
 rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4562
 fqdir_free_fn+0x32/0x140 net/ipv4/inet_fragment.c:167
 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>
INFO: task syz-executor:16907 blocked for more than 144 seconds.
      Not tainted 6.12.0-rc6-syzkaller-00099-g7758b206117d #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:20992 pid:16907 tgid:16907 ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5328 [inline]
 __schedule+0x184f/0x4c30 kernel/sched/core.c:6690
 __schedule_loop kernel/sched/core.c:6767 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6782
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6839
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
 rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4562
 netdev_run_todo+0x3a0/0x1000 net/core/dev.c:10786
 tun_detach drivers/net/tun.c:704 [inline]
 tun_chr_close+0x137/0x1b0 drivers/net/tun.c:3517
 __fput+0x23f/0x880 fs/file_table.c:431
 task_work_run+0x24f/0x310 kernel/task_work.c:239
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0xa2f/0x28e0 kernel/exit.c:939
 do_group_exit+0x207/0x2c0 kernel/exit.c:1088
 get_signal+0x16a3/0x1740 kernel/signal.c:2917
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f17a757d15c
RSP: 002b:00007f17a785fd90 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: fffffffffffffe00 RBX: 0000000000000003 RCX: 00007f17a757d15c
RDX: 0000000000000028 RSI: 00007f17a785fe40 RDI: 00000000000000f9
RBP: 00007f17a785fdec R08: 0000000000000000 R09: 0079746972756365
R10: 00007f17a77097e0 R11: 0000000000000246 R12: 000055556327e5eb
R13: 000055556327e590 R14: 000000000007eff8 R15: 00007f17a785fe40
 </TASK>
INFO: task syz-executor:17419 blocked for more than 145 seconds.
      Not tainted 6.12.0-rc6-syzkaller-00099-g7758b206117d #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:20992 pid:17419 tgid:17419 ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5328 [inline]
 __schedule+0x184f/0x4c30 kernel/sched/core.c:6690
 __schedule_loop kernel/sched/core.c:6767 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6782
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6839
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
 rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4562
 netdev_run_todo+0x3a0/0x1000 net/core/dev.c:10786
 tun_detach drivers/net/tun.c:704 [inline]
 tun_chr_close+0x137/0x1b0 drivers/net/tun.c:3517
 __fput+0x23f/0x880 fs/file_table.c:431
 task_work_run+0x24f/0x310 kernel/task_work.c:239
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0xa2f/0x28e0 kernel/exit.c:939
 do_group_exit+0x207/0x2c0 kernel/exit.c:1088
 get_signal+0x16a3/0x1740 kernel/signal.c:2917
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f85d037d15c
RSP: 002b:00007f85d065fd90 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: fffffffffffffe00 RBX: 0000000000000003 RCX: 00007f85d037d15c
RDX: 0000000000000028 RSI: 00007f85d065fe40 RDI: 00000000000000f9
RBP: 00007f85d065fdec R08: 0000000000000000 R09: 0079746972756365
R10: 00007f85d05097e0 R11: 0000000000000246 R12: 00005555932db5eb
R13: 00005555932db590 R14: 000000000007f46e R15: 00007f85d065fe40
 </TASK>
INFO: task syz.5.1777:18178 blocked for more than 146 seconds.
      Not tainted 6.12.0-rc6-syzkaller-00099-g7758b206117d #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.1777      state:D stack:18192 pid:18178 tgid:18170 ppid:17700  flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5328 [inline]
 __schedule+0x184f/0x4c30 kernel/sched/core.c:6690
 __schedule_loop kernel/sched/core.c:6767 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6782
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6839
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
 rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4562
 kvm_mmu_uninit_vm+0x2f/0x60 arch/x86/kvm/mmu/mmu.c:6566
 kvm_arch_destroy_vm+0x3a8/0x430 arch/x86/kvm/x86.c:12886
 kvm_destroy_vm virt/kvm/kvm_main.c:1350 [inline]
 kvm_put_kvm+0xd61/0x1350 virt/kvm/kvm_main.c:1386
 kvm_vm_release+0x43/0x50 virt/kvm/kvm_main.c:1409
 __fput+0x23f/0x880 fs/file_table.c:431
 task_work_run+0x24f/0x310 kernel/task_work.c:239
 get_signal+0x15e8/0x1740 kernel/signal.c:2690
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f856677e31b
RSP: 002b:00007f85675df490 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007f85675dfbe0 RCX: 00007f856677e31b
RDX: 00007f85675dfbe0 RSI: 000000004020ae46 RDI: 0000000000000004
RBP: 0000000000000004 R08: 0000000000000001 R09: 0000000000000055
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000004
R13: 0000000020fec000 R14: 0000000020fe8000 R15: 00000000fec00000
 </TASK>
INFO: task syz-executor:18199 blocked for more than 147 seconds.
      Not tainted 6.12.0-rc6-syzkaller-00099-g7758b206117d #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:26360 pid:18199 tgid:18199 ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5328 [inline]
 __schedule+0x184f/0x4c30 kernel/sched/core.c:6690
 __schedule_loop kernel/sched/core.c:6767 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6782
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6839
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
 rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4562
 setup_net+0x8ff/0x9e0 net/core/net_namespace.c:394
 copy_net_ns+0x33f/0x570 net/core/net_namespace.c:494
 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
 ksys_unshare+0x57d/0xa70 kernel/fork.c:3313
 __do_sys_unshare kernel/fork.c:3384 [inline]
 __se_sys_unshare kernel/fork.c:3382 [inline]
 __x64_sys_unshare+0x38/0x40 kernel/fork.c:3382
 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: 0033:0x7fdd5117ff17
RSP: 002b:00007fdd5145ffa8 EFLAGS: 00000206 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fdd511f2b8d RCX: 00007fdd5117ff17
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 0000000000000000 R08: 00007fdd51e67d60 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 000000000000000c
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
6 locks held by kworker/u8:0/11:
 #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90000107d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90000107d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcc6dd0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:580
 #3: ffff88805cd450e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #3: ffff88805cd450e8 (&dev->mutex){....}-{3:3}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline]
 #3: ffff88805cd450e8 (&dev->mutex){....}-{3:3}, at: devlink_pernet_pre_exit+0x13b/0x440 net/devlink/core.c:506
 #4: ffff88805cd46250 (&devlink->lock_key#40){+.+.}-{3:3}, at: devl_lock net/devlink/core.c:276 [inline]
 #4: ffff88805cd46250 (&devlink->lock_key#40){+.+.}-{3:3}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline]
 #4: ffff88805cd46250 (&devlink->lock_key#40){+.+.}-{3:3}, at: devlink_pernet_pre_exit+0x14d/0x440 net/devlink/core.c:506
 #5: ffffffff8e93d200 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4562
3 locks held by ksoftirqd/0/16:
1 lock held by khungtaskd/30:
 #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720
2 locks held by kworker/u8:8/3447:
2 locks held by getty/5595:
 #0: ffff88814d31f0a0 (&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
3 locks held by kworker/1:8/5927:
 #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90004657d00 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90004657d00 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8e93d200 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4562
1 lock held by syz-executor/16907:
 #0: ffffffff8e93d200 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4562
1 lock held by syz-executor/17419:
 #0: ffffffff8e93d200 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4562
1 lock held by syz.1.1723/17681:
 #0: ffffffff8e93d200 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4562
1 lock held by syz.5.1777/18178:
 #0: ffffffff8e93d200 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4562
2 locks held by syz-executor/18199:
 #0: ffffffff8fcc6dd0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490
 #1: ffffffff8e93d200 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4562
4 locks held by syz-executor/18229:
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff888032d3dc88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff888144b26008 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f571728 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
4 locks held by syz-executor/18232:
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff8880787a1488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff888144b26008 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f571728 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
4 locks held by syz-executor/18234:
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff888078e74888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff888144b26008 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f571728 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
7 locks held by syz-executor/18239:
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff888033ab8c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff888144b26008 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f571728 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
 #4: ffff888049add0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #4: ffff888049add0e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline]
 #4: ffff888049add0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293
 #5: ffff888049ade250 (&devlink->lock_key#28){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675
 #6: ffffffff8e93d200 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4562
1 lock held by syz-executor/18263:
 #0: ffffffff8e93d200 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4562
4 locks held by syz-executor/18557:
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff888143785088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff888144b26008 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f571728 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
4 locks held by syz-executor/18590:
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff888053c8a488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff888144b26008 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f571728 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
4 locks held by syz-executor/18605:
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff8880280f2488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff888144b26008 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f571728 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
4 locks held by syz-executor/18611:
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff8880668f1488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff888144b26008 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f571728 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
4 locks held by syz-executor/18613:
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff888054ed5888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff888144b26008 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f571728 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
4 locks held by syz-executor/19433:
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff88804cdc5888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff888144b26008 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f571728 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
4 locks held by syz-executor/19467:
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff88809217f888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff888144b26008 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f571728 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
4 locks held by syz-executor/19480:
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff888028041488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff888144b26008 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f571728 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
4 locks held by syz-executor/19483:
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff8880ac29b488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff888144b26008 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f571728 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
4 locks held by syz-executor/19494:
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888030d62420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff8880accde488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff888144b26008 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f571728 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
2 locks held by dhcpcd/20057:
 #0: ffff88804dcb6258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1611 [inline]
 #0: ffff88804dcb6258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcb0 net/packet/af_packet.c:3266
 #1: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline]
 #1: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc6-syzkaller-00099-g7758b206117d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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: 16 Comm: ksoftirqd/0 Not tainted 6.12.0-rc6-syzkaller-00099-g7758b206117d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4831 [inline]
RIP: 0010:__lock_acquire+0x6ef/0x2050 kernel/locking/lockdep.c:5152
Code: 11 00 00 48 8d 04 fe 48 89 44 24 40 40 84 ed 4c 8b 6c 24 48 0f 84 37 04 00 00 0f b6 1b 41 0f b6 04 16 84 c0 0f 85 f3 11 00 00 <41> f6 47 01 80 0f 85 1c 04 00 00 84 db 40 0f b6 c5 0f b6 cb 0f 44
RSP: 0018:ffffc900001575d0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8170541f
RDX: dffffc0000000000 RSI: ffff88801ce8e4e0 RDI: 0000000000000005
RBP: 0000000000000002 R08: ffffffff942cd83f R09: 1ffffffff2859b07
R10: dffffc0000000000 R11: fffffbfff2859b08 R12: ffff88801ce8da00
R13: ffff88801ce8e4d8 R14: 1ffff110039d1ca5 R15: ffff88801ce8e528
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055dfc92fed88 CR3: 000000000e734000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
 ref_tracker_free+0x121/0x7e0 lib/ref_tracker.c:243
 netdev_tracker_free include/linux/netdevice.h:4082 [inline]
 netdev_put include/linux/netdevice.h:4099 [inline]
 dst_destroy+0x105/0x360 net/core/dst.c:114
 rcu_do_batch kernel/rcu/tree.c:2567 [inline]
 rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823
 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554
 run_ksoftirqd+0xca/0x130 kernel/softirq.c:927
 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164
 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>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/07 05:13 upstream 7758b206117d df3dc63b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in fqdir_free_fn
2024/09/28 21:17 upstream 3efc57369a0c ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in fqdir_free_fn
2024/09/23 12:00 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 68d4209158f4 89298aad .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in fqdir_free_fn
2024/07/20 15:34 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 3c3ff7be9729 b88348e9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in fqdir_free_fn
* Struck through repros no longer work on HEAD.