INFO: task syz-executor:7034 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21768 pid:7034 tgid:7034 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block+0x5ba/0x6d0 kernel/locking/rtmutex.c:1647 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline] rt_mutex_slowlock+0x2b1/0x6e0 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:536 [inline] mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:547 lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 jfs_umount+0x2ef/0x3c0 fs/jfs/jfs_umount.c:114 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x135/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1730 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318 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+0xe9/0x130 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/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f229ab50a77 RSP: 002b:00007ffc599c41a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f229abd3d7d RCX: 00007f229ab50a77 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc599c4260 RBP: 00007ffc599c4260 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc599c52f0 R13: 00007f229abd3d7d R14: 0000000000032c44 R15: 00007ffc599c5330 INFO: task syz-executor:7162 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21768 pid:7162 tgid:7162 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block+0x5ba/0x6d0 kernel/locking/rtmutex.c:1647 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline] rt_mutex_slowlock+0x2b1/0x6e0 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:536 [inline] mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:547 lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 jfs_umount+0x2ef/0x3c0 fs/jfs/jfs_umount.c:114 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x135/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1730 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318 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+0xe9/0x130 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/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ffba2070a77 RSP: 002b:00007ffc021519c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007ffba20f3d7d RCX: 00007ffba2070a77 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc02151a80 RBP: 00007ffc02151a80 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc02152b10 R13: 00007ffba20f3d7d R14: 000000000003f854 R15: 00007ffc02152b50 Showing all locks held in the system: 3 locks held by rcuc/0/20: 1 lock held by khungtaskd/39: #0: ffffffff8d5a9e80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5a9e80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5a9e80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 6 locks held by kworker/u8:7/1298: 2 locks held by dhcpcd/5463: #0: ffff88807fa54920 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xbd/0xe90 net/netlink/af_netlink.c:2269 #1: ffffffff8e8635f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8e8635f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6819 2 locks held by getty/5556: #0: ffff88823bf688a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/0:3/5808: #0: ffff88813ff55138 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff55138 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90004c3fba0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90004c3fba0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff88803a096260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x224/0x3e0 drivers/net/netdevsim/fib.c:1490 2 locks held by syz-executor/6344: #0: ffff8880266ca0d0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880266ca0d0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880266ca0d0 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8d9df498 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz-executor/7034: #0: ffff88803b8020d0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88803b8020d0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88803b8020d0 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8d9df498 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz-executor/7162: #0: ffff8880367f80d0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880367f80d0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880367f80d0 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8d9df498 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz-executor/7188: #0: ffff88808f8080d0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88808f8080d0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88808f8080d0 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8d9df498 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 7 locks held by syz-executor/7921: #0: ffff888034006480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3173 [inline] #0: ffff888034006480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff8880490c3c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8881453362d8 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8881453362d8 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e0f3fb8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 #4: ffff88823bf640d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #4: ffff88823bf640d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 #5: ffff88808751d300 (&devlink->lock_key#26){+.+.}-{4:4}, at: nsim_drv_probe+0xc2/0xba0 drivers/net/netdevsim/dev.c:1582 #6: ffffffff8e8635f8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1047 [inline] #6: ffffffff8e8635f8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_create+0x800/0x1060 drivers/net/netdevsim/netdev.c:1141 1 lock held by syz-executor/7925: #0: ffffffff8e8635f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8e8635f8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978 4 locks held by syz-executor/7930: #0: ffff888034006480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3173 [inline] #0: ffff888034006480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff888077225c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8881453362d8 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8881453362d8 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e0f3fb8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 4 locks held by syz-executor/7991: #0: ffff888034006480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3173 [inline] #0: ffff888034006480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff88808ab9a878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8881453363c8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8881453363c8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e0f3fb8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234 4 locks held by syz-executor/8003: #0: ffff888034006480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3173 [inline] #0: ffff888034006480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff88803295b878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8881453363c8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8881453363c8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e0f3fb8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 7921 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__lock_acquire+0x121/0xd20 kernel/locking/lockdep.c:5146 Code: f5 28 5c 8f 48 0f af f0 45 85 f6 0f 85 4a 01 00 00 45 85 ed 0f 84 41 01 00 00 41 83 fd 31 0f 83 12 01 00 00 48 83 7c 24 68 00 <0f> 84 2b 01 00 00 48 8d 87 60 0b 00 00 4a 8d 0c ad 00 00 00 00 4c RSP: 0018:ffffc9002b76ef50 EFLAGS: 00000046 RAX: 000000000000165d RBX: ffff8880b8843668 RCX: ffffffff924c1310 RDX: 0000000000000008 RSI: 00000000000000e5 RDI: ffff888030b88000 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: ffff88807fe30b30 R11: ffffed100ffc6168 R12: 0000000000000000 R13: 0000000000000008 R14: 0000000000000000 R15: 0000000000000000 FS: 000055558c415500(0000) GS:ffff888126de9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005612901e1000 CR3: 00000000549bc000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 rt_spin_lock+0x88/0x3e0 kernel/locking/spinlock_rt.c:56 spin_lock include/linux/spinlock_rt.h:44 [inline] ___slab_alloc+0x12f/0x1400 mm/slub.c:4520 __slab_alloc+0xc6/0x1f0 mm/slub.c:4778 __slab_alloc_node mm/slub.c:4854 [inline] slab_alloc_node mm/slub.c:5276 [inline] kmem_cache_alloc_noprof+0xec/0x6b0 mm/slub.c:5295 lsm_inode_alloc security/security.c:761 [inline] security_inode_alloc+0x39/0x330 security/security.c:1736 inode_init_always_gfp+0x9bf/0xd70 fs/inode.c:306 inode_init_always include/linux/fs.h:3374 [inline] alloc_inode+0x82/0x1b0 fs/inode.c:353 new_inode+0x22/0x170 fs/inode.c:1175 debugfs_get_inode fs/debugfs/inode.c:72 [inline] __debugfs_create_file+0x14d/0x4f0 fs/debugfs/inode.c:442 debugfs_create_file_unsafe+0x3a/0x50 fs/debugfs/inode.c:518 nsim_bpf_init+0x163/0x250 drivers/net/netdevsim/bpf.c:635 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1052 [inline] nsim_create+0xb0c/0x1060 drivers/net/netdevsim/netdev.c:1141 __nsim_dev_port_add+0x6b6/0xb10 drivers/net/netdevsim/dev.c:1438 nsim_dev_port_add_all+0x37/0xf0 drivers/net/netdevsim/dev.c:1494 nsim_drv_probe+0x884/0xba0 drivers/net/netdevsim/dev.c:1653 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0x9e0 drivers/base/dd.c:659 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:801 driver_probe_device+0x4f/0x430 drivers/base/dd.c:831 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:959 bus_for_each_drv+0x254/0x2e0 drivers/base/bus.c:462 __device_attach+0x2bb/0x400 drivers/base/dd.c:1031 bus_probe_device+0x188/0x260 drivers/base/bus.c:537 device_add+0x7b6/0xb50 drivers/base/core.c:3689 nsim_bus_dev_new drivers/net/netdevsim/bus.c:463 [inline] new_device_store+0x36c/0x6f0 drivers/net/netdevsim/bus.c:191 kernfs_fop_write_iter+0x3b0/0x540 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5d5/0xb40 fs/read_write.c:686 ksys_write+0x14b/0x260 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcf8268e1ff Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48 RSP: 002b:00007fff5cf43f50 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fcf8268e1ff RDX: 0000000000000003 RSI: 00007fff5cf43fa0 RDI: 0000000000000005 RBP: 00007fcf827152ef R08: 0000000000000000 R09: 00007fff5cf43da7 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 00007fff5cf43fa0 R14: 00007fcf83414620 R15: 0000000000000003