INFO: task syz.4.32:5942 blocked for more than 142 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.32 state:D stack:25976 pid:5942 tgid:5939 ppid:5874 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x17dd/0x5940 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7362 schedule_timeout+0xc0/0x2c0 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2ca/0x5e0 kernel/sched/completion.c:153 __cld_pipe_upcall fs/nfsd/nfs4recover.c:674 [inline] cld_pipe_upcall fs/nfsd/nfs4recover.c:692 [inline] nfsd4_cld_grace_start fs/nfsd/nfs4recover.c:1306 [inline] nfsd4_cld_tracking_init+0xda0/0x13a0 fs/nfsd/nfs4recover.c:1495 nfsd4_client_tracking_init+0xca/0x1c0 fs/nfsd/nfs4recover.c:1942 nfs4_state_start_net+0xc95/0x1180 fs/nfsd/nfs4state.c:10009 nfsd_startup_net fs/nfsd/nfssvc.c:399 [inline] nfsd_svc+0x481/0x710 fs/nfsd/nfssvc.c:783 write_threads+0x434/0x610 fs/nfsd/nfsctl.c:440 nfsctl_transaction_write+0x10f/0x160 fs/nfsd/nfsctl.c:116 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: 0033:0x7eff1b99e159 RSP: 002b:00007eff1c8d5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007eff1bc26090 RCX: 00007eff1b99e159 RDX: 0000000000000002 RSI: 0000200000000100 RDI: 0000000000000005 RBP: 00007eff1ba35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007eff1bc26128 R14: 00007eff1bc26090 R15: 00007ffcc03fe718 INFO: task syz.5.35:5967 blocked for more than 142 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.35 state:D stack:27432 pid:5967 tgid:5966 ppid:5900 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x17dd/0x5940 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7362 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7419 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c9/0x15a0 kernel/locking/mutex.c:821 write_versions+0x95/0xe30 fs/nfsd/nfsctl.c:710 nfsctl_transaction_write+0x10f/0x160 fs/nfsd/nfsctl.c:116 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: 0033:0x7f57a499e159 RSP: 002b:00007f57a57a2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f57a4c25fa0 RCX: 00007f57a499e159 RDX: 0000000000000005 RSI: 0000200000000140 RDI: 0000000000000003 RBP: 00007f57a4a35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f57a4c26038 R14: 00007f57a4c25fa0 R15: 00007ffc237e7728 INFO: task syz.5.35:5968 blocked for more than 142 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.35 state:D stack:27432 pid:5968 tgid:5966 ppid:5900 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x17dd/0x5940 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7362 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7419 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c9/0x15a0 kernel/locking/mutex.c:821 write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:869 nfsctl_transaction_write+0x10f/0x160 fs/nfsd/nfsctl.c:116 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: 0033:0x7f57a499e159 RSP: 002b:00007f57a5781028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f57a4c26090 RCX: 00007f57a499e159 RDX: 0000000000000009 RSI: 00002000000001c0 RDI: 0000000000000004 RBP: 00007f57a4a35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f57a4c26128 R14: 00007f57a4c26090 R15: 00007ffc237e7728 INFO: task syz.5.35:5969 blocked for more than 142 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.35 state:D stack:27432 pid:5969 tgid:5966 ppid:5900 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x17dd/0x5940 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7362 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7419 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c9/0x15a0 kernel/locking/mutex.c:821 write_threads+0x3b1/0x610 fs/nfsd/nfsctl.c:438 nfsctl_transaction_write+0x10f/0x160 fs/nfsd/nfsctl.c:116 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: 0033:0x7f57a499e159 RSP: 002b:00007f57a2bf6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f57a4c26180 RCX: 00007f57a499e159 RDX: 0000000000000002 RSI: 0000200000000240 RDI: 0000000000000005 RBP: 00007f57a4a35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f57a4c26218 R14: 00007f57a4c26180 R15: 00007ffc237e7728 INFO: task syz.6.37:6015 blocked for more than 142 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.37 state:D stack:25696 pid:6015 tgid:6014 ppid:5972 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x17dd/0x5940 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7362 do_uevent+0x2c3/0x570 fs/dlm/lockspace.c:206 new_lockspace fs/dlm/lockspace.c:583 [inline] __dlm_new_lockspace+0x17d1/0x1cd0 fs/dlm/lockspace.c:638 device_create_lockspace+0xc7/0x350 fs/dlm/user.c:414 device_write+0x872/0xed0 fs/dlm/user.c:606 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: 0033:0x7fe56f79e159 RSP: 002b:00007fe5706e7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fe56fa25fa0 RCX: 00007fe56f79e159 RDX: 0000000000000080 RSI: 00002000000004c0 RDI: 0000000000000008 RBP: 00007fe56f835024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe56fa26038 R14: 00007fe56fa25fa0 R15: 00007ffde94636c8 Showing all locks held in the system: locks held by khungtaskd/31: 1, last CPU#0: #0: ffffffff8ef5c9a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ef5c9a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ef5c9a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6837 locks held by getty/5375: 2, on CPU#1: #0: ffff8880328b40a0 (&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 locks held by kworker/0:3/5688: 6, on CPU#0: #0: ffff888022af3140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff888022af3140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff888022af3140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3364 [inline] #0: ffff888022af3140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3482 #1: ffffc90004197c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90004197c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90004197c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3364 [inline] #1: ffffc90004197c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3482 #2: ffff8880290d81d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff8880290d81d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5912 #3: ffff8880297571d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff8880297571d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073 #4: ffff88805dfd41a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #4: ffff88805dfd41a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073 #5: ffffffff8edf7d88 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xfc/0x2c0 kernel/umh.c:212 locks held by syz.4.32/5942: 3, on CPU#1: #0: ffff88802553a470 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259 #1: ffff888031310460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline] #1: ffff888031310460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #2: ffffffff8f2a00c0 (nfsd_mutex){+.+.}-{4:4}, at: write_threads+0x3b1/0x610 fs/nfsd/nfsctl.c:438 locks held by syz.5.35/5967: 3, on CPU#0: #0: ffff88802b791430 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259 #1: ffff888020f7a460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline] #1: ffff888020f7a460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #2: ffffffff8f2a00c0 (nfsd_mutex){+.+.}-{4:4}, at: write_versions+0x95/0xe30 fs/nfsd/nfsctl.c:710 locks held by syz.5.35/5968: 3, on CPU#0: #0: ffff88802b7907f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259 #1: ffff888020f7a460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline] #1: ffff888020f7a460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #2: ffffffff8f2a00c0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:869 locks held by syz.5.35/5969: 3, on CPU#0: #0: ffff88802b7909b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259 #1: ffff888020f7a460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline] #1: ffff888020f7a460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #2: ffffffff8f2a00c0 (nfsd_mutex){+.+.}-{4:4}, at: write_threads+0x3b1/0x610 fs/nfsd/nfsctl.c:438 locks held by syz.6.37/6015: 1, on CPU#1: #0: ffffffff9ad35c60 (&ls_lock){+.+.}-{4:4}, at: __dlm_new_lockspace+0xa8/0x1cd0 fs/dlm/lockspace.c:632 locks held by dlm_recoverd/6017: 1, on CPU#1: #0: ffff88807ddbea18 (&ls->ls_in_recovery){+.+.}-{4:4}, at: dlm_recoverd+0xbc/0x2a00 fs/dlm/recoverd.c:400 locks held by kworker/0:7/6237: 7, on CPU#0: #0: ffff88813ff42940 ((wq_completion)events_long){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88813ff42940 ((wq_completion)events_long){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88813ff42940 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3364 [inline] #0: ffff88813ff42940 ((wq_completion)events_long){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3482 #1: ffffc90005d3fc40 (serio_event_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90005d3fc40 (serio_event_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90005d3fc40 (serio_event_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3364 [inline] #1: ffffc90005d3fc40 (serio_event_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3482 #2: ffffffff8fed8ee0 (serio_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #2: ffffffff8fed8ee0 (serio_mutex){+.+.}-{4:4}, at: serio_handle_event+0x25/0xf80 drivers/input/serio/serio.c:190 #3: ffff888077149320 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff888077149320 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073 #4: ffff8880771491d0 (&serio->drv_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #4: ffff8880771491d0 (&serio->drv_mutex){+.+.}-{4:4}, at: serio_connect_driver drivers/input/serio/serio.c:42 [inline] #4: ffff8880771491d0 (&serio->drv_mutex){+.+.}-{4:4}, at: serio_driver_probe+0x58/0xa0 drivers/input/serio/serio.c:748 #5: ffffffff8fee8d80 (psmouse_mutex){+.+.}-{4:4}, at: psmouse_connect+0x94/0x13f0 drivers/input/mouse/psmouse-base.c:1559 #6: ffff88802bb34078 (&ps2dev->cmd_mutex){+.+.}-{4:4}, at: ps2_begin_command drivers/input/serio/libps2.c:132 [inline] #6: ffff88802bb34078 (&ps2dev->cmd_mutex){+.+.}-{4:4}, at: ps2_command+0x70/0xe0 drivers/input/serio/libps2.c:402 locks held by syz.1.55/6282: 1, on CPU#0: #0: ffffffff9ad35c60 (&ls_lock){+.+.}-{4:4}, at: __dlm_new_lockspace+0xa8/0x1cd0 fs/dlm/lockspace.c:632 locks held by syz.0.65/6376: 3, on CPU#0: #0: ffff888035121eb0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259 #1: ffff8880346b4460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline] #1: ffff8880346b4460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #2: ffffffff8f2a00c0 (nfsd_mutex){+.+.}-{4:4}, at: write_versions+0x95/0xe30 fs/nfsd/nfsctl.c:710 locks held by syz.0.65/6377: 3, on CPU#1: #0: ffff88807b32a470 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259 #1: ffff8880346b4460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline] #1: ffff8880346b4460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #2: ffffffff8f2a00c0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:869 locks held by syz.0.65/6378: 3, on CPU#0: #0: ffff88807d0cb0b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259 #1: ffff8880346b4460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline] #1: ffff8880346b4460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #2: ffffffff8f2a00c0 (nfsd_mutex){+.+.}-{4:4}, at: write_threads+0x3b1/0x610 fs/nfsd/nfsctl.c:438 locks held by udevd/6438: 4, on CPU#0: #0: ffff888033b91998 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xa4/0xca0 fs/seq_file.c:183 #1: ffff88804e4b5c80 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5d/0x420 fs/kernfs/file.c:165 #2: ffff88802aa84e18 (kn->active#28){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff88802aa84e18 (kn->active#28){.+.+}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:166 #3: ffff8880297571d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1109 [inline] #3: ffff8880297571d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 locks held by syz.3.75/6757: 3, on CPU#1: #0: ffff88803ca4e0f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259 #1: ffff8880735a6460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline] #1: ffff8880735a6460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #2: ffffffff8f2a00c0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:869 locks held by syz.3.75/6763: 3, on CPU#1: #0: ffff88805f80d0b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259 #1: ffff8880735a6460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline] #1: ffff8880735a6460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #2: ffffffff8f2a00c0 (nfsd_mutex){+.+.}-{4:4}, at: write_versions+0x95/0xe30 fs/nfsd/nfsctl.c:710 locks held by syz.3.75/6766: 3, on CPU#0: #0: ffff88807e5a95f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259 #1: ffff8880735a6460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline] #1: ffff8880735a6460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #2: ffffffff8f2a00c0 (nfsd_mutex){+.+.}-{4:4}, at: write_threads+0x3b1/0x610 fs/nfsd/nfsctl.c:438 locks held by syz.4.80/6824: 3, on CPU#0: #0: ffff888012ca89b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259 #1: ffff88805aae2460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline] #1: ffff88805aae2460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #2: ffffffff8f2a00c0 (nfsd_mutex){+.+.}-{4:4}, at: write_versions+0x95/0xe30 fs/nfsd/nfsctl.c:710 locks held by syz.4.80/6827: 3, on CPU#0: #0: ffff88807b3180f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259 #1: ffff88805aae2460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline] #1: ffff88805aae2460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #2: ffffffff8f2a00c0 (nfsd_mutex){+.+.}-{4:4}, at: write_pool_threads+0x113/0x8e0 fs/nfsd/nfsctl.c:487 locks held by syz.2.223/7965: 1, on CPU#0: #0: ffff88805e264378 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:548 [inline] #0: ffff88805e264378 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1dd/0x4e0 mm/util.c:579 locks held by syz.2.223/7966: 2, last CPU#0: #0: ffff88805e264378 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:586 [inline] #0: ffff88805e264378 (&mm->mmap_lock){++++}-{4:4}, at: __mm_populate+0x182/0x390 mm/gup.c:1942 #1: ffffffff8ef5c9a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8ef5c9a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8ef5c9a0 (rcu_read_lock){....}-{1:3}, at: count_memcg_events_mm include/linux/memcontrol.h:980 [inline] #1: ffffffff8ef5c9a0 (rcu_read_lock){....}-{1:3}, at: count_memcg_event_mm+0x21/0x260 include/linux/memcontrol.h:990 locks held by syz.6.224/7970: 1, on CPU#0: #0: ffffffff8fed8ee0 (serio_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff8fed8ee0 (serio_mutex){+.+.}-{4:4}, at: serio_unregister_port+0x2f/0x150 drivers/input/serio/serio.c:677 locks held by syz.1.225/7973: 2, on CPU#0: #0: ffffffff904db5a8 (cb_lock){++++}-{4:4}, at: ctrl_getfamily+0x242/0x5c0 net/netlink/genetlink.c:1451 #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: ctrl_getfamily+0x250/0x5c0 net/netlink/genetlink.c:1452 locks held by syz.1.225/7977: 4, last CPU#0: #0: ffffffff904db5a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 #2: ffffffff8f87e5a8 (vdpa_dev_lock){+.+.}-{4:4}, at: vdpa_nl_cmd_dev_add_set_doit+0x582/0xbd0 drivers/vdpa/vdpa.c:628 #3: ffffffff8ef5c9a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #3: ffffffff8ef5c9a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8ef5c9a0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline] #3: ffffffff8ef5c9a0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495 locks held by syz.1.225/7979: 2, on CPU#0: #0: ffffffff904db5a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz.1.225/7980: 2, on CPU#0: #0: ffffffff904db5a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz.1.225/7982: 2, on CPU#0: #0: ffffffff904db5a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz.1.225/7984: 2, on CPU#0: #0: ffffffff904db5a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz.1.225/7985: 2, on CPU#0: #0: ffffffff904db5a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff904db3e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 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+0x105d/0x10e0 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