INFO: task syz.2.390:5393 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.390 state:D stack:27088 pid:5393 ppid:4278 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6698 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x548/0xae0 kernel/locking/mutex.c:747 nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783 write_threads+0x2ea/0x350 fs/nfsd/nfsctl.c:424 nfsctl_transaction_write+0x105/0x150 fs/nfsd/nfsctl.c:114 vfs_write+0x2dc/0x9a0 fs/read_write.c:582 ksys_write+0x14d/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7ffa8219e159 RSP: 002b:00007ffa830ac028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ffa82426090 RCX: 00007ffa8219e159 RDX: 0000000000000002 RSI: 0000200000000700 RDI: 0000000000000003 RBP: 00007ffa8223506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffa82426128 R14: 00007ffa82426090 R15: 00007ffe7b529058 INFO: task syz.5.400:5474 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.400 state:D stack:27088 pid:5474 ppid:5383 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6698 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x548/0xae0 kernel/locking/mutex.c:747 nfsd4_write_time+0xa4/0x330 fs/nfsd/nfsctl.c:980 nfsctl_transaction_write+0x105/0x150 fs/nfsd/nfsctl.c:114 vfs_write+0x2dc/0x9a0 fs/read_write.c:582 ksys_write+0x14d/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fbb1479e159 RSP: 002b:00007fbb1571d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fbb14a25fa0 RCX: 00007fbb1479e159 RDX: 0000000000000002 RSI: 0000200000000240 RDI: 0000000000000003 RBP: 00007fbb1483506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbb14a26038 R14: 00007fbb14a25fa0 R15: 00007fff2ebbb8d8 Showing all locks held in the system: 7 locks held by kworker/0:0/7: #0: ffff8880176a4538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc900000c7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #2: ffff888146f5c190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline] #2: ffff888146f5c190 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5200 drivers/usb/core/hub.c:5850 #3: ffff888038715190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline] #3: ffff888038715190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:1009 #4: ffff88808f68c118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline] #4: ffff88808f68c118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:1009 #5: ffff88807b7f40f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_alloc_board_minor+0x121/0x500 drivers/comedi/comedi_fops.c:3336 #6: ffffffff8c9da310 (umhelper_sem){++++}-{3:3}, at: usermodehelper_read_trylock+0xf9/0x2b0 kernel/umh.c:218 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2e170 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2e990 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8cb2d7e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2d7e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2d7e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6529 2 locks held by getty/4029: #0: ffff88814db8d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198 3 locks held by kworker/0:5/4323: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc90004277d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #2: ffff888018e89240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x283/0x3320 drivers/net/netdevsim/fib.c:1491 3 locks held by syz.2.390/5392: #0: ffff88807cc1b4e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88807706a460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 3 locks held by syz.2.390/5393: #0: ffff88802e6819e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88807706a460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783 3 locks held by syz.5.400/5474: #0: ffff88801d7479e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff8880707ba460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd4_write_time+0xa4/0x330 fs/nfsd/nfsctl.c:980 3 locks held by syz.6.404/5597: #0: ffff888024c4f9e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888073dec460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 3 locks held by syz.6.404/5598: #0: ffff88807c868368 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888073dec460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783 3 locks held by syz.8.401/5615: #0: ffff888078d07c68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888077864460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 3 locks held by syz.8.401/5617: #0: ffff88802ae83268 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888077864460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783 3 locks held by syz.7.409/5645: #0: ffff8880744a6d68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888026e1e460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:681 3 locks held by syz.7.409/5648: #0: ffff88807e0665e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888026e1e460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 3 locks held by syz.7.409/5649: #0: ffff888024c574e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888026e1e460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783 3 locks held by syz.9.403/5700: #0: ffff8880731c65e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88802c0c6460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:681 3 locks held by syz.9.403/5702: #0: ffff88805e4b8ae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88802c0c6460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 3 locks held by syz.9.403/5706: #0: ffff8880296e0868 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88802c0c6460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783 3 locks held by syz.4.414/5783: #0: ffff8880287eaae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88807b7aa460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:681 3 locks held by syz.4.414/5785: #0: ffff88806224f268 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88807b7aa460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 1 lock held by syz.4.414/5788: #0: ffff88806224f268 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 2 locks held by syz-executor/5900: #0: ffff8880781c20e0 (&type->s_umount_key#53){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x4f/0x1a0 fs/nfsd/nfssvc.c:633 4 locks held by udevd/5992: #0: ffff8880391f1c30 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0x9d/0xc50 fs/seq_file.c:182 #1: ffff888083103888 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x59/0x410 fs/kernfs/file.c:172 #2: ffff888095fd9cb8 (kn->active#5){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888095fd9cb8 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0xae/0x410 fs/kernfs/file.c:173 #3: ffff888038715190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline] #3: ffff888038715190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16e/0x320 drivers/base/core.c:2669 3 locks held by syz.1.434/6136: #0: ffff88802f82cd68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff8880523d4460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 3 locks held by kworker/u4:10/6173: 3 locks held by syz.5.462/6288: #0: ffff888052078d68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88807ca6a460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:681 3 locks held by syz.5.462/6289: #0: ffff88805fce0368 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88807ca6a460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 3 locks held by syz.5.462/6293: #0: ffff888079cac368 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88807ca6a460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783 3 locks held by syz.6.510/6521: #0: ffff888024c6aae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888075348460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd4_write_time+0xa4/0x330 fs/nfsd/nfsctl.c:980 3 locks held by syz.6.510/6522: #0: ffff88802e4ce5e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888075348460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:681 3 locks held by syz.6.510/6523: #0: ffff88807cfbd768 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888075348460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 3 locks held by syz.6.510/6524: #0: ffff8880786aad68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888075348460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783 3 locks held by syz.0.517/6557: #0: ffff88806244a868 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88807587e460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 1 lock held by syz.0.517/6558: #0: ffff88806244a868 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 3 locks held by syz.2.518/6561: #0: ffff88807a4945e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff8880274aa460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:681 3 locks held by syz.2.518/6562: #0: ffff88807a4959e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff8880274aa460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 3 locks held by syz.2.518/6563: #0: ffff88807d618d68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff8880274aa460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783 3 locks held by syz.7.541/6664: #0: ffff8880782359e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888053276460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 3 locks held by syz.7.541/6665: #0: ffff888078234d68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888053276460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783 3 locks held by syz.8.546/6687: #0: ffff8880789025e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88808ac0c460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 3 locks held by syz.8.546/6688: #0: ffff8880778bf4e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88808ac0c460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783 2 locks held by syz-executor/6804: #0: ffff888055fbc0e0 (&type->s_umount_key#53){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x4f/0x1a0 fs/nfsd/nfssvc.c:633 3 locks held by syz.9.574/6826: #0: ffff8880661c5c68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88807c5fa460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:681 6 locks held by syz.1.576/6834: #0: ffff88807c9e8868 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88807d6cc460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffff888051b33088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1d8/0x520 fs/kernfs/file.c:343 #3: ffff88801841ebd0 (kn->active#80){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #3: ffff88801841ebd0 (kn->active#80){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x520 fs/kernfs/file.c:344 #4: ffffffff8c9e2aa8 (system_transition_mutex){+.+.}-{3:3}, at: enter_state kernel/power/suspend.c:575 [inline] #4: ffffffff8c9e2aa8 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend+0x3bc/0x9a0 kernel/power/suspend.c:626 #5: ffff8880781c20e0 (&type->s_umount_key#53){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755 3 locks held by syz.4.612/6962: #0: ffff888027d000e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888029a30460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:681 3 locks held by syz.4.612/6963: #0: ffff88807cd4cfe8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888029a30460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 3 locks held by syz.4.612/6966: #0: ffff88807846bc68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888029a30460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783 3 locks held by syz.3.619/6984: #0: ffff8880277b0868 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88808f834460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:681 3 locks held by syz.3.619/6987: #0: ffff88807c9e80e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88808f834460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 3 locks held by syz.3.619/6989: #0: ffff888078902ae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88808f834460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783 4 locks held by syz-executor/6992: #0: ffff8880964511e0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:521 [inline] #0: ffff8880964511e0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x20e/0x500 net/bluetooth/hci_core.c:2718 #1: ffff888096450428 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x506/0x1040 net/bluetooth/hci_sync.c:5300 #2: ffffffff8deb3b48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1833 [inline] #2: ffffffff8deb3b48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xac/0x290 net/bluetooth/hci_conn.c:2563 #3: ffffffff8cb334b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #3: ffffffff8cb334b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962 3 locks held by syz.0.634/7054: #0: ffff88807c869268 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88809b6ce460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783 2 locks held by syz-executor/7091: #0: ffff88808e1ac0e0 (&type->s_umount_key#53){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x4f/0x1a0 fs/nfsd/nfssvc.c:633 3 locks held by syz.2.636/7111: #0: ffff88807c3c8ae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888052040460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:681 3 locks held by syz.2.636/7113: #0: ffff88807cadfc68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888052040460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:681 3 locks held by syz.2.636/7114: #0: ffff88807ac20fe8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888052040460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 3 locks held by syz.2.636/7115: #0: ffff88807a1c2fe8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888052040460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783 2 locks held by syz-executor/7116: #0: ffff88802e10e0e0 (&type->s_umount_key#53){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x4f/0x1a0 fs/nfsd/nfssvc.c:633 5 locks held by syz.9.658/7223: #0: ffff8880279c1c68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888050b20460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffff88808f16ac88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1d8/0x520 fs/kernfs/file.c:343 #3: ffff88801de792c0 (kn->active#4){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #3: ffff88801de792c0 (kn->active#4){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x520 fs/kernfs/file.c:344 #4: ffffffff8c9df728 (param_lock){+.+.}-{3:3}, at: kernel_param_lock kernel/params.c:598 [inline] #4: ffffffff8c9df728 (param_lock){+.+.}-{3:3}, at: param_attr_store+0xcb/0x300 kernel/params.c:583 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf0e/0xf50 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4329 Comm: kworker/u4:5 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:stack_trace_consume_entry+0x12a/0x270 kernel/stacktrace.c:95 Code: 62 00 49 89 e8 4c 89 e2 48 89 de 49 89 37 41 8b 18 41 0f b6 44 15 00 84 c0 0f 85 2f 01 00 00 41 3b 1e 0f 92 c0 48 83 c4 18 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 44 89 c1 80 e1 07 80 c1 03 38 c1 0f RSP: 0018:ffffc900044676f8 EFLAGS: 00000296 RAX: 0000000000000001 RBX: ffffc900044677e0 RCX: 0000000080000000 RDX: dffffc0000000000 RSI: ffffffff81d371d7 RDI: ffffc900044677e0 RBP: 1ffff9200088cefe R08: ffffc900044677f0 R09: 0000000000000001 R10: dffffc0000000000 R11: fffff5200088cef1 R12: 0000000000000000 R13: 1ffff9200088cefd R14: ffffc900044677e8 R15: ffffc90004467868 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000559f179e4f70 CR3: 000000002e060000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x100/0x140 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] kmem_cache_free+0xf7/0x2a0 mm/slub.c:3709 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x71f/0xa80 drivers/net/netdevsim/dev.c:851 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295