INFO: task syz.2.20:5882 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.20 state:D stack:27432 pid:5882 tgid:5876 ppid:5622 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5535 [inline]
__schedule+0x1b47/0x5c60 kernel/sched/core.c:7305
__schedule_loop kernel/sched/core.c:7382 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7397
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7454
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
write_threads+0x3b1/0x610 fs/nfsd/nfsctl.c:439
nfsctl_transaction_write+0x10f/0x160 fs/nfsd/nfsctl.c:117
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:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f775e79e159
RSP: 002b:00007f775f692028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f775ea26090 RCX: 00007f775e79e159
RDX: 0000000000000002 RSI: 0000200000000700 RDI: 0000000000000005
RBP: 00007f775e83506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f775ea26128 R14: 00007f775ea26090 R15: 00007ffe9d5e9288
Showing all locks held in the system:
locks held by kworker/u8:0/12: 7, last CPU#1:
#0: ffff888033024148 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff888033024148 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff888033024148 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff888033024148 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc90000117c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90000117c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90000117c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc90000117c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffff88807ec8a790 (btrfs_ordered_extent){++++}-{0:0}, at: btrfs_finish_one_ordered+0x362/0x2550 fs/btrfs/inode.c:3229
#3: ffff88802e46c650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_finish_one_o
#3: ffff88802e46c650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_finish_one_ordered+0x7e4/0x2550 fs/btrfs/inode.c:3264
#4: ffff88807ec8a678 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0xc4d/0x1030 fs/btrfs/transaction.c:296
#5: ffff88807ec8a6a0 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0xc4d/0x1030 fs/btrfs/transaction.c:296
#6: ffff88807a6840f0 (btrfs-csum-00/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x45/0x250 fs/btrfs/locking.c:189
locks held by khungtaskd/34: 1, last CPU#1:
#0: ffffffff8ed5e2a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ed5e2a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ed5e2a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kworker/u8:3/51: 7, on CPU#1:
#0: ffff888033024148 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff888033024148 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff888033024148 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff888033024148 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc90000bb7c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90000bb7c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90000bb7c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc90000bb7c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffff88807ec8a790 (btrfs_ordered_extent){++++}-{0:0}, at: btrfs_finish_one_ordered+0x362/0x2550 fs/btrfs/inode.c:3229
#3: ffff88802e46c650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_finish_one_ordered+0x7e4/0x2550 fs/btrfs/inode.c:3264
#4: ffff88807ec8a678 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0xc4d/0x1030 fs/btrfs/transaction.c:296
#5: ffff88807ec8a6a0 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0xc4d/0x1030 fs/btrfs/transaction.c:296
#6: ffff88807a6840f0 (btrfs-csum-00){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x45/0x250 fs/btrfs/locking.c:146
locks held by kworker/u8:6/159: 3, last CPU#1:
#0: ffff8880318f1148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff8880318f1148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff8880318f1148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff8880318f1148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc90002effc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90002effc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90002effc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc90002effc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffffffff90250420 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline]
#2: ffffffff90250420 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4775
locks held by kworker/u8:7/978: 7, on CPU#1:
#0: ffff888033024148 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff888033024148 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff888033024148 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff888033024148 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc90004b97c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90004b97c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90004b97c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc90004b97c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffff88807ec8a790 (btrfs_ordered_extent){++++}-{0:0}, at: btrfs_finish_one_ordered+0x362/0x2550 fs/btrfs/inode.c:3229
#3: ffff88802e46c650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_finish_one_ordered+0x7e4/0x2550 fs/btrfs/inode.c:3264
#4: ffff88807ec8a678 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0xc4d/0x1030 fs/btrfs/transaction.c:296
#5: ffff88807ec8a6a0 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0xc4d/0x1030 fs/btrfs/transaction.c:296
#6: ffff88807a6840f0 (btrfs-csum-00){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x45/0x250 fs/btrfs/locking.c:146
locks held by kworker/u8:8/1700: 7, on CPU#1:
#0: ffff888033024148 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff888033024148 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff888033024148 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff888033024148 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc90005fd7c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90005fd7c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90005fd7c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc90005fd7c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffff88807ec8a790 (btrfs_ordered_extent){++++}-{0:0}, at: btrfs_finish_one_ordered+0x362/0x2550 fs/btrfs/inode.c:3229
#3: ffff88802e46c650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_finish_one_ordered+0x7e4/0x2550 fs/btrfs/inode.c:3264
#4: ffff88807ec8a678 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0xc4d/0x1030 fs/btrfs/transaction.c:296
#5: ffff88807ec8a6a0 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0xc4d/0x1030 fs/btrfs/transaction.c:296
#6: ffff88807a6840f0 (btrfs-csum-00){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x45/0x250 fs/btrfs/locking.c:146
locks held by kworker/u8:9/2234: 2, on CPU#1:
#0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc90006abfc40 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90006abfc40 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90006abfc40 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc90006abfc40 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
locks held by kworker/u8:10/3289: 2, last CPU#1:
#0: ffff888022774148 ((wq_completion)btrfs-delalloc){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff888022774148 ((wq_completion)btrfs-delalloc){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff888022774148 ((wq_completion)btrfs-delalloc){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff888022774148 ((wq_completion)btrfs-delalloc){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc9000e697c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9000e697c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9000e697c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc9000e697c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
locks held by kworker/u8:11/3330: 2, last CPU#1:
#0: ffff888031b3a948 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff888031b3a948 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff888031b3a948 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff888031b3a948 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc9000e7d7c40 ((work_completion)(&(&bat_priv->mcast.work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9000e7d7c40 ((work_completion)(&(&bat_priv->mcast.work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9000e7d7c40 ((work_completion)(&(&bat_priv->mcast.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc9000e7d7c40 ((work_completion)(&(&bat_priv->mcast.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
locks held by kworker/u8:12/3366: 3, last CPU#1:
#0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc9000e827c40 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9000e827c40 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9000e827c40 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc9000e827c40 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffff888055d50800 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6908 [inline]
#2: ffff888055d50800 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0xb4/0x420 net/wireless/core.c:550
locks held by syslogd/4963: 1, last CPU#1:
#0: ffff888034e39f70 (&u->iolock){+.+.}-{4:4}, at: __unix_dgram_recvmsg+0x1e3/0xd70 net/unix/af_unix.c:2587
locks held by getty/5376: 2, on CPU#0:
#0: ffff8880355e40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by kworker/1:8/5808: 3, on CPU#1:
#0: ffff8880206be548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff8880206be548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff8880206be548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff8880206be548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc9000495fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9000495fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9000495fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc9000495fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffff88802a2e91d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff88802a2e91d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5917
locks held by syz.2.20/5880: 3, on CPU#0:
#0: ffff8880328e5cf0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x118/0x160 fs/file.c:1273
#1: ffff88807ebbe460 (sb_writers#15){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#1: ffff88807ebbe460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#2: ffffffff8f0a0c80 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:874
locks held by syz.2.20/5882: 3, on CPU#0:
#0: ffff888079cd5270 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x118/0x160 fs/file.c:1273
#1: ffff88807ebbe460 (sb_writers
#15){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#15){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#2: ffffffff8f0a0c80 (nfsd_mutex){+.+.}-{4:4}, at: write_threads+0x3b1/0x610 fs/nfsd/nfsctl.c:439
locks held by syz.1.433/7427: 2, on CPU#1:
#0: ffff88807c81c0e8 (&type->s_umount_key#100){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88807c81c0e8 (&type->s_umount_key#100){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff88807c81c0e8 (&type->s_umount_key#100){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:613
#1: ffffffff8f0a0c80 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:590
locks held by syz-executor/8543: 1, last CPU#1:
#0: ffffffff8ed5e2a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ed5e2a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ed5e2a0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#0: ffffffff8ed5e2a0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by syz.5.758/8749: 2, last CPU#1:
#0: ffff888028b8e9b8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:586 [inline]
#0: ffff888028b8e9b8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1299
#1: ffffffff8ed5e2a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8ed5e2a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8ed5e2a0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:302
locks held by syz.7.769/8743: 3, on CPU#0:
#0: ffff888074b791c8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:309
#1: ffff88802e46c558 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x147/0x310 mm/memory.c:3875
#2: ffff8880b863c1a0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160 kernel/sched/core.c:678
locks held by dhcpcd-run-hook/8768: 2, last CPU#1:
#0: ffff88807f26d038 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:530 [inline]
#0: ffff88807f26d038 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2d8/0x9f0 mm/mmap.c:1323
#1: ffffffff8ed5e2a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8ed5e2a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8ed5e2a0 (rcu_read_lock){....}-{1:3}, at: is_bpf_text_address+0x26/0x2b0 kernel/bpf/core.c:750
locks held by udevadm/8769: 1, last CPU#1:
#0: ffff88807f26a9f8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:548 [inline]
#0: ffff88807f26a9f8 (&mm->mmap_lock){++++}-{4:4}, at: do_mprotect_pkey+0x25c/0xd10 mm/mprotect.c:901
locks held by syz-executor/8778: 1, last CPU#1:
#0: ffffffff8ed5e2a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ed5e2a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ed5e2a0 (rcu_read_lock){....}-{1:3}, at: is_bpf_text_address+0x26/0x2b0 kernel/bpf/core.c:750
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [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:377 [inline]
watchdog+0x1058/0x10d0 kernel/hung_task.c:598
kthread+0x38b/0x480 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16 Comm: pr/ttyS0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409
Code: e8 1e 43 50 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 5f 90 c1 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 5a 59 75 06 cc 44 89 f9 80 e1 07
RSP: 0018:ffffc900001578b8 EFLAGS: 00000002
RAX: 1ffffffff35abd00 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff85789f40 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9ad5eba0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124caf000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fac54d97a16 CR3: 000000002e924000 CR4: 00000000003526f0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x184/0x2f0 drivers/tty/serial/8250/8250_port.c:2013
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3270 [inline]
__serial8250_console_fifo_write+0x346/0x3e0 drivers/tty/serial/8250/8250_port.c:3372
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline]
__serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline]
serial8250_console_write+0xaa1/0x1200 drivers/tty/serial/8250/8250_port.c:3493
nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1
nbcon_emit_one kernel/printk/nbcon.c:1157 [inline]
nbcon_kthread_func+0x6d9/0x8d0 kernel/printk/nbcon.c:1271
kthread+0x38b/0x480 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