INFO: task syz.9.1144:11772 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.1144 state:D stack:22760 pid:11772 ppid:10038 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
wb_wait_for_completion+0x166/0x290 fs/fs-writeback.c:192
sync_inodes_sb+0x1bc/0x9e0 fs/fs-writeback.c:2772
sync_filesystem+0x171/0x220 fs/sync.c:64
generic_shutdown_super+0x6f/0x2b0 fs/super.c:666
kill_block_super+0x44/0x90 fs/super.c:1660
deactivate_locked_super+0x97/0x100 fs/super.c:481
cleanup_mnt+0x429/0x4c0 fs/namespace.c:1259
task_work_run+0x1ce/0x250 kernel/task_work.c:239
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x90b/0x23c0 kernel/exit.c:883
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
get_signal+0x12fc/0x1400 kernel/signal.c:2902
arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315
exc_general_protection+0x170/0x200 arch/x86/kernel/traps.c:745
asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:602
RIP: 0033:0x7f1c74f8f6d1
RSP: 002b:0000200000000450 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f1c751e6090 RCX: 00007f1c74f8f6c9
RDX: 0000200000000980 RSI: 0000200000000450 RDI: 0000000040100000
RBP: 00007f1c75011f91 R08: 0000200000000a00 R09: 0000200000000a00
R10: 00002000000009c0 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f1c751e6128 R14: 00007f1c751e6090 R15: 00007ffdca41b118
Showing all locks held in the system:
6 locks held by kworker/1:1/27:
#0: ffff888147a6a938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888147a6a938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90000a2fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90000a2fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888024c0c190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#2: ffff888024c0c190 (&dev->mutex){....}-{3:3}, at: hub_event+0x185/0x49c0 drivers/usb/core/hub.c:5861
#3: ffff888024c0f508 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3215 [inline]
#3: ffff888024c0f508 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5426 [inline]
#3: ffff888024c0f508 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5669 [inline]
#3: ffff888024c0f508 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5833 [inline]
#3: ffff888024c0f508 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x21ab/0x49c0 drivers/usb/core/hub.c:5915
#4: ffff8880245d9868 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5427 [inline]
#4: ffff8880245d9868 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5669 [inline]
#4: ffff8880245d9868 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5833 [inline]
#4: ffff8880245d9868 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x21d3/0x49c0 drivers/usb/core/hub.c:5915
#5: ffff8880b8e3c218 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:566
1 lock held by khungtaskd/29:
#0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
6 locks held by kworker/u4:5/74:
#0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900015d7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900015d7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffffffff8dfaeed0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x136/0xb90 net/core/net_namespace.c:606
#3: ffff888030488250 (&devlink->lock_key#13){+.+.}-{3:3}, at: devl_lock net/devlink/core.c:60 [inline]
#3: ffff888030488250 (&devlink->lock_key#13){+.+.}-{3:3}, at: devlink_pernet_pre_exit+0xe1/0x340 net/devlink/core.c:285
#4: ffffffff8dfbbd08 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x3f/0x180 drivers/net/netdevsim/netdev.c:417
#5: ffffffff8cd358b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#5: ffffffff8cd358b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004
2 locks held by kworker/u4:6/1092:
2 locks held by getty/5553:
#0: ffff88802cfd40a0 (&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+0x425/0x1380 drivers/tty/n_tty.c:2217
2 locks held by kworker/u4:12/8316:
#0: ffff88801e280d38 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801e280d38 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90004a1fd00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90004a1fd00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
3 locks held by kworker/u4:14/8318:
2 locks held by kworker/1:7/10854:
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000566fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000566fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
2 locks held by syz.9.1144/11772:
#0: ffff88807e9da0e0 (&type->s_umount_key#92){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline]
#0: ffff88807e9da0e0 (&type->s_umount_key#92){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff88807e9da0e0 (&type->s_umount_key#92){++++}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
#1: ffff88814131e7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
#1: ffff88814131e7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a0/0x9e0 fs/fs-writeback.c:2770
1 lock held by segctord/11860:
#0: ffff8880b8e3c218 (&rq->__lock){-.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#0: ffff8880b8e3c218 (&rq->__lock){-.-.}-{2:2}, at: nilfs_segctor_thread+0xaf4/0x1000 fs/nilfs2/segment.c:2674
1 lock held by syz.1.1195/12073:
#0: ffff88807e9da0e0 (&type->s_umount_key#92){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88807e9da0e0 (&type->s_umount_key#92){++++}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117
1 lock held by syz.7.1203/12144:
#0: ffff88807e9da0e0 (&type->s_umount_key#92){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88807e9da0e0 (&type->s_umount_key#92){++++}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117
7 locks held by syz-executor/13858:
#0: ffff8880313d4418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x20e/0x940 fs/read_write.c:580
#1: ffff888018755088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x520 fs/kernfs/file.c:343
#2: ffff88802258d5d8 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802258d5d8 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x23a/0x520 fs/kernfs/file.c:344
#3: ffffffff8d897be8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd2/0x360 drivers/net/netdevsim/bus.c:209
#4: ffff88807f0900e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#4: ffff88807f0900e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline]
#4: ffff88807f0900e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb6/0x7a0 drivers/base/dd.c:1292
#5: ffff888078087250 (&devlink->lock_key#5){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675
#6: ffffffff8dfbbd08 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x3f/0x180 drivers/net/netdevsim/netdev.c:417
1 lock held by syz-executor/13997:
#0: ffffffff8dfbbd08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
#0: ffffffff8dfbbd08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469
4 locks held by dhcpcd-run-hook/14022:
=============================================
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 10/02/2025
Call Trace:
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 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+0xf41/0xf80 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
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 14010 Comm: dhcpcd-run-hook Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x10/0x60 kernel/kcov.c:216
Code: 89 fb e8 13 00 00 00 48 8b 3d 0c 00 c5 0c 48 89 de 5b e9 a3 8a 56 00 cc cc cc f3 0f 1e fa 48 8b 04 24 65 48 8b 0d 20 28 7e 7e <65> 8b 15 21 28 7e 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75
RSP: 0018:ffffc900032e7860 EFLAGS: 00000286
RAX: ffffffff812ec6e9 RBX: ffffc900032e7908 RCX: ffff8880281e9e00
RDX: 0000000000000000 RSI: ffff8880281e9e00 RDI: ffffc900032e78a0
RBP: dffffc0000000000 R08: ffffc900032e7967 R09: 0000000000000000
R10: ffffc900032e7908 R11: fffff5200065cf2d R12: ffffc900032e78a0
R13: ffffc900032e7928 R14: ffffc900032e7928 R15: ffff8880281e9e00
FS: 00007f220d49ac80(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a3b0db8138 CR3: 000000007c7a7000 CR4: 00000000003506e0
Call Trace:
get_stack_info+0x29/0x170 arch/x86/kernel/dumpstack_64.c:194
__unwind_start+0x48b/0x7e0 arch/x86/kernel/unwind_orc.c:729
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xf8/0x190 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1811 [inline]
slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
kmem_cache_free+0xf8/0x280 mm/slub.c:3852
vfs_fstatat+0x134/0x1b0 fs/stat.c:300
__do_sys_newfstatat fs/stat.c:463 [inline]
__se_sys_newfstatat fs/stat.c:457 [inline]
__x64_sys_newfstatat+0x117/0x190 fs/stat.c:457
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f220d654b0a
Code: 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 07 31 c0 c3 0f 1f 40 00 48 8b 15 b9 f2 0d 00 f7
RSP: 002b:00007ffec34f4478 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007f220d654b0a
RDX: 00007ffec34f4488 RSI: 000055a3b0db30b8 RDI: 00000000ffffff9c
RBP: 000055a3b0da4040 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f220d7dc324
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000