INFO: task syz.3.5250:24325 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.5250 state:D stack:27864 pid:24325 tgid:24323 ppid:17941 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821
write_threads+0x39d/0x5a0 fs/nfsd/nfsctl.c:432
nfsctl_transaction_write+0x10f/0x160 fs/nfsd/nfsctl.c:112
vfs_write+0x296/0xba0 fs/read_write.c:685
ksys_write+0x150/0x270 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fadce19de99
RSP: 002b:00007fadcf0d2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fadce425fa0 RCX: 00007fadce19de99
RDX: 0000000000000001 RSI: 0000200000000380 RDI: 0000000000000003
RBP: 00007fadce233eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fadce426038 R14: 00007fadce425fa0 R15: 00007ffc7d2b58c8
Showing all locks held in the system:
3 locks held by kworker/u8:1/13:
#0: ffff88801b064140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88801b064140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc90000127c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc90000127c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffffffff9002d700 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
1 lock held by khungtaskd/32:
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:4/58:
#0: ffff8880b863b160 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160 kernel/sched/core.c:667
#1: ffff8880b8624440 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x57/0x7d0 kernel/sched/psi.c:933
#2: ffff8880b863b160 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160 kernel/sched/core.c:667
#3: ffffffff9aa2e900 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0xb7/0x420 lib/debugobjects.c:873
2 locks held by getty/5369:
#0: ffff88803228e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
3 locks held by kworker/1:9/11932:
#0: ffff88801b02b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88801b02b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc9000f79fc40 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc9000f79fc40 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#2: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
1 lock held by syz-executor/16294:
6 locks held by kworker/u8:16/18364:
#0: ffff88801c28e140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88801c28e140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc900034f7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc900034f7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffffffff9001eb48 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:673
#3: ffff88807d886128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline]
#3: ffff88807d886128 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline]
#3: ffff88807d886128 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:557
#4: ffff88807a185258 (&devlink->lock_key#23){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline]
#4: ffff88807a185258 (&devlink->lock_key#23){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline]
#4: ffff88807a185258 (&devlink->lock_key#23){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:557
#5: ffffffff9002d700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#5: ffffffff9002d700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2163
1 lock held by syz-executor/22126:
#0: ffff888042f44ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:497 [inline]
#0: ffff888042f44ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x22a/0x5b0 net/bluetooth/hci_core.c:2678
2 locks held by syz-executor/24083:
#0: ffff888067464ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:497 [inline]
#0: ffff888067464ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x22a/0x5b0 net/bluetooth/hci_core.c:2678
#1: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
3 locks held by syz.7.5219/24153:
#0: ffff888049a05eb0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
#1: ffff888032b1e450 (sb_writers#28){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline]
#1: ffff888032b1e450 (sb_writers#28){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#2: ffffffff8ee8e620 (nfsd_mutex){+.+.}-{4:4}, at: write_threads+0x39d/0x5a0 fs/nfsd/nfsctl.c:432
3 locks held by syz.3.5250/24325:
#0: ffff888074be0ef0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
#1: ffff88805111e450 (sb_writers#28){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline]
#1: ffff88805111e450 (sb_writers#28){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#2: ffffffff8ee8e620 (nfsd_mutex){+.+.}-{4:4}, at: write_threads+0x39d/0x5a0 fs/nfsd/nfsctl.c:432
7 locks held by syz-executor/25419:
#0: ffff888033dda450 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline]
#0: ffff888033dda450 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#1: ffff8880548dd880 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540 fs/kernfs/file.c:336
#2: ffff8880298a6f08 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff8880298a6f08 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22b/0x540 fs/kernfs/file.c:337
#3: ffffffff8f8a96a0 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234
#4: ffff8880527a5128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline]
#4: ffff8880527a5128 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline]
#4: ffff8880527a5128 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369
#5: ffff88801bb79258 (&devlink->lock_key#19){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x170 drivers/net/netdevsim/dev.c:1799
#6: ffffffff9002d700 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x173/0x800 drivers/net/netdevsim/netdev.c:1191
1 lock held by syz-executor/25597:
#0: ffffffff9002d700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff9002d700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff9002d700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158
1 lock held by syz.4.5582/25868:
#0: ffff888053a68ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:497 [inline]
#0: ffff888053a68ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x22a/0x5b0 net/bluetooth/hci_core.c:2678
1 lock held by sed/25884:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 25597 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:desc_read+0x1fe/0x3f0 kernel/printk/printk_ringbuffer.c:500
Code: 00 0f 84 90 00 00 00 e8 80 f5 1f 00 48 8b 5c 24 18 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 b5 8c 8d 00 48 8b 1b <48> 8b 7c 24 10 48 89 f8 48 c1 e8 03 42 80 3c 20 00 74 0a e8 8a 8d
RSP: 0018:ffffc9000751e480 EFLAGS: 00000246
RAX: 1ffffffff1d4fd39 RBX: 00000000000022af RCX: ffff8880259a9f00
RDX: 0000000000000000 RSI: ffffffff8ea37da0 RDI: ffffc9000751e5d8
RBP: ffffffff8ea37d88 R08: ffffc9000751e5d7 R09: 1ffff92000ea3cba
R10: dffffc0000000000 R11: fffff52000ea3cbb R12: dffffc0000000000
R13: 0000000000000000 R14: 1ffffffff1d46fb1 R15: 3fffffffffffffff
FS: 0000555572a3b500(0000) GS:ffff88812504e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5c7e32c000 CR3: 000000004545e000 CR4: 0000000000350ef0
Call Trace:
desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1934 [inline]
prb_read kernel/printk/printk_ringbuffer.c:1982 [inline]
_prb_read_valid+0x286/0xa50 kernel/printk/printk_ringbuffer.c:2173
prb_read_valid+0x3c/0x60 kernel/printk/printk_ringbuffer.c:2245
printk_get_next_message+0x18b/0x880 kernel/printk/printk.c:3052
console_emit_next_record kernel/printk/printk.c:3137 [inline]
console_flush_one_record kernel/printk/printk.c:3269 [inline]
console_flush_all+0x4e3/0xaf0 kernel/printk/printk.c:3343
__console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
_printk+0xdd/0x130 kernel/printk/printk.c:2504
br_set_state+0x4c9/0x6f0 net/bridge/br_stp.c:57
br_init_port+0x99/0x200 net/bridge/br_stp_if.c:39
new_nbp+0x4af/0x640 net/bridge/br_if.c:449
br_add_if+0x279/0xeb0 net/bridge/br_if.c:592
do_set_master+0x563/0x720 net/core/rtnetlink.c:3020
do_setlink+0xe7b/0x4670 net/core/rtnetlink.c:3222
rtnl_changelink net/core/rtnetlink.c:3849 [inline]
__rtnl_newlink net/core/rtnetlink.c:4022 [inline]
rtnl_newlink+0x15c2/0x1bd0 net/core/rtnetlink.c:4159
rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7076
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775
__sock_sendmsg net/socket.c:790 [inline]
__sys_sendto+0x408/0x5a0 net/socket.c:2252
__do_sys_sendto net/socket.c:2259 [inline]
__se_sys_sendto net/socket.c:2255 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2255
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5bb7f5e6ce
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007fff59f18588 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000555572a3b500 RCX: 00007f5bb7f5e6ce
RDX: 0000000000000028 RSI: 00007f5bb8d54670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007fff59f18604 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f5bb8d54670 R15: 0000000000000000