INFO: task syz.9.964:10291 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.964 state:D stack:25096 pid:10291 tgid:10291 ppid:8300 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 bdev_release+0x1a9/0x650 block/bdev.c:1128 blkdev_release+0x15/0x20 block/fops.c:702 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f142638eba9 RSP: 002b:00007ffdaf9b0b48 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f14265d7da0 RCX: 00007f142638eba9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f14265d7da0 R08: 00000000000015fc R09: 00000008af9b0e3f R10: 00000000003fe7e0 R11: 0000000000000246 R12: 0000000000072860 R13: 00007ffdaf9b0c40 R14: ffffffffffffffff R15: 00007ffdaf9b0c60 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:3/49: #0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:644 #1: ffff8880b8724008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 3 locks held by kworker/u8:5/150: #0: ffff88801a481148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801a481148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90002ee7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90002ee7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8f539c08 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by getty/5615: #0: ffff8880306de0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by kworker/u9:3/5872: #0: ffff888025926948 ((wq_completion)nbd9-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888025926948 ((wq_completion)nbd9-recv){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000423fbc0 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000423fbc0 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 1 lock held by udevd/6013: #0: ffff88802592d358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 1 lock held by syz-executor/8227: #0: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 1 lock held by syz.9.964/10291: #0: ffff88802592d358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1128 1 lock held by syz.7.1278/11588: #0: ffff88802592d358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288 1 lock held by syz.7.1278/11590: #0: ffff88802592d358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288 1 lock held by syz.7.1278/11591: #0: ffff88802592d358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288 1 lock held by syz.7.1278/11592: #0: ffff88802592d358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288 1 lock held by syz.7.1278/11593: #0: ffff88802592d358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288 1 lock held by syz.7.1278/11594: #0: ffff88802592d358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288 1 lock held by syz.7.1278/11595: #0: ffff88802592d358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288 1 lock held by syz.7.1278/11596: #0: ffff88802592d358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288 9 locks held by syz-executor/11770: #0: ffff888023414428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3108 [inline] #0: ffff888023414428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xb30 fs/read_write.c:682 #1: ffff8880522de488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325 #2: ffff888026c295a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0 fs/kernfs/file.c:326 #3: ffffffff8edaff28 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234 #4: ffff8880534340e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #4: ffff8880534340e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline] #4: ffff8880534340e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294 #5: ffff88805347a250 (&devlink->lock_key){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1721 #6: ffffffff8f539c08 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xe5/0x670 drivers/net/netdevsim/netdev.c:1135 #7: ffff888023f14d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2761 [inline] #7: ffff888023f14d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] #7: ffff888023f14d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0xdf5/0x1ff0 net/core/dev.c:12153 #8: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #8: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 1 lock held by sed/12000: ============================================= 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 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 10540 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:lock_is_held_type+0x0/0x190 kernel/locking/lockdep.c:5925 Code: 1f 09 f6 90 0f 0b 90 90 90 eb b5 e8 1a fc ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 10 65 48 8b 05 RSP: 0018:ffffc900051b70c0 EFLAGS: 00000092 RAX: ffffffff8b78357c RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff888020b18000 RSI: 00000000ffffffff RDI: ffff88802a2590d0 RBP: 0000000000000000 R08: ffff88802572cfff R09: 1ffff11004ae59ff R10: dffffc0000000000 R11: ffffed1004ae5a00 R12: 0000000000000000 R13: ffff88802a2590d0 R14: dffffc0000000000 R15: 00000000ffffffff FS: 0000000000000000(0000) GS:ffff888125d15000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560f259e6950 CR3: 000000007d8cc000 CR4: 0000000000350ef0 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] xa_entry_locked include/linux/xarray.h:1235 [inline] xas_store+0x851/0x1880 lib/xarray.c:843 page_cache_delete mm/filemap.c:141 [inline] __filemap_remove_folio+0x3c7/0x500 mm/filemap.c:224 filemap_remove_folio+0xe6/0x1f0 mm/filemap.c:253 truncate_inode_folio+0x5d/0x70 mm/truncate.c:176 shmem_undo_range+0x3a9/0x14b0 mm/shmem.c:1153 shmem_truncate_range mm/shmem.c:1269 [inline] shmem_evict_inode+0x272/0xa70 mm/shmem.c:1397 evict+0x504/0x9c0 fs/inode.c:810 __dentry_kill+0x209/0x660 fs/dcache.c:669 shrink_kill+0xa9/0x2c0 fs/dcache.c:1114 shrink_dentry_list+0x2e0/0x5e0 fs/dcache.c:1141 shrink_dcache_parent+0xa1/0x2c0 fs/dcache.c:-1 do_one_tree+0x23/0xe0 fs/dcache.c:1604 shrink_dcache_for_umount+0xa0/0x170 fs/dcache.c:1621 generic_shutdown_super+0x67/0x2c0 fs/super.c:621 kill_anon_super fs/super.c:1282 [inline] kill_litter_super+0x76/0xb0 fs/super.c:1292 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:961 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 __do_sys_exit_group kernel/exit.c:1113 [inline] __se_sys_exit_group kernel/exit.c:1111 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc65ff8eba9 Code: Unable to access opcode bytes at 0x7fc65ff8eb7f. RSP: 002b:00007fff87c95d38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fc660013653 RCX: 00007fc65ff8eba9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043 RBP: 00007fc660013665 R08: 00007fff87c93ad7 R09: 00000000000927c0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006 R13: 00000000000927c0 R14: 0000000000097370 R15: 00007fff87c95ee0