INFO: task syz-executor:18846 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:22504 pid:18846 tgid:18846 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7668 rwbase_write_lock+0x3cf/0x720 kernel/locking/rwbase_rt.c:279 __super_lock fs/super.c:60 [inline] __super_lock_excl fs/super.c:75 [inline] deactivate_super+0xac/0xe0 fs/super.c:613 cleanup_mnt+0x204/0x2a0 fs/namespace.c:1396 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0c8fdff797 RSP: 002b:00007ffe0b47b098 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f0c8fe94efb RCX: 00007f0c8fdff797 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe0b47b150 RBP: 00007ffe0b47b150 R08: 00007ffe0b47c150 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe0b47c1e0 R13: 00007f0c8fe94efb R14: 0000000000150201 R15: 00007ffe0b47c220 INFO: task syz.7.1136:20411 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.1136 state:D stack:23624 pid:20411 tgid:20408 ppid:18696 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7376 jfs_flush_journal+0x719/0xf50 fs/jfs/jfs_logmgr.c:1561 jfs_sync_fs+0x7d/0xa0 fs/jfs/super.c:650 dquot_quota_sync+0xd1/0x490 fs/quota/dquot.c:782 __iterate_supers+0x282/0x420 fs/super.c:980 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:938 [inline] __se_sys_quotactl+0x3a0/0x9f0 fs/quota/quota.c:917 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: 0033:0x7f2d1007e559 RSP: 002b:00007f2d0e2d6028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f2d10305fa0 RCX: 00007f2d1007e559 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007f2d10115ab8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2d10306038 R14: 00007f2d10305fa0 R15: 00007fff4ac1c598 Showing all locks held in the system: locks held by khungtaskd/38: 1, last CPU#0: #0: ffffffff8f1c3d00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8f1c3d00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8f1c3d00 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871 locks held by getty/5346: 2, on CPU#0: #0: ffff888037c020a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900044d32e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 locks held by kworker/0:10/12023: 3, on CPU#0: #0: ffff88813ff2b938 ((wq_completion)events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88813ff2b938 ((wq_completion)events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88813ff2b938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88813ff2b938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc90004c3fc40 (netdev_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90004c3fc40 (netdev_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90004c3fc40 (netdev_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc90004c3fc40 (netdev_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #2: ffffffff905d6a38 (rtnl_mutex){+.+.}-{4:4}, at: netdev_work_proc+0x72/0x7f0 net/core/netdev_work.c:132 locks held by kworker/u8:1/13677: 7, last CPU#0: #0: ffff88801beb0938 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801beb0938 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801beb0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88801beb0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc900050cfc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc900050cfc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc900050cfc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc900050cfc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #2: ffffffff905c8200 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:677 #3: ffff888062a9b160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff888062a9b160 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline] #3: ffff888062a9b160 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:581 #4: ffff888038bac310 (&devlink->lock_key#87){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:314 [inline] #4: ffff888038bac310 (&devlink->lock_key#87){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline] #4: ffff888038bac310 (&devlink->lock_key#87){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:581 #5: ffff88803a2c0818 (&dir->lock#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #5: ffff88803a2c0818 (&dir->lock#2){+.+.}-{3:3}, at: ref_tracker_dir_exit+0x13f/0x650 lib/ref_tracker.c:231 #6: ffffffff8f1c3d00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #6: ffffffff8f1c3d00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #6: ffffffff8f1c3d00 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #6: ffffffff8f1c3d00 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e2/0x400 kernel/locking/spinlock_rt.c:57 locks held by kworker/u8:7/14594: 3, on CPU#0: #0: ffff88803437b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88803437b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88803437b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88803437b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc90004befc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90004befc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90004befc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc90004befc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #2: ffffffff905d6a38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline] #2: ffffffff905d6a38 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x123/0x16e0 net/ipv6/addrconf.c:4230 locks held by kworker/u8:20/14598: 3, on CPU#0: #0: ffff88813ff64138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88813ff64138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88813ff64138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88813ff64138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc9000439fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc9000439fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc9000439fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc9000439fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #2: ffffffff905d6a38 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 locks held by syz-executor/18846: 1, on CPU#0: #0: ffff8880666c00e0 (&type->s_umount_key#73){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880666c00e0 (&type->s_umount_key#73){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline] #0: ffff8880666c00e0 (&type->s_umount_key#73){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:613 locks held by syz.7.1136/20411: 1, on CPU#0: #0: ffff8880666c00e0 (&type->s_umount_key#73){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline] #0: ffff8880666c00e0 (&type->s_umount_key#73){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:124 locks held by syz-executor/21549: 1, on CPU#0: #0: ffffffff905d6a38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff905d6a38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline] #0: ffffffff905d6a38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4219 locks held by syz-executor/21758: 8, last CPU#0: #0: ffff888033464510 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2756 [inline] #0: ffff888033464510 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff88806adcf078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff88802afa02d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff88802afa02d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8fe46d78 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x6d0 drivers/net/netdevsim/bus.c:184 #4: ffff88803fbad160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #4: ffff88803fbad160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073 #5: ffff888058ed0310 (&devlink->lock_key#89){+.+.}-{4:4}, at: nsim_drv_probe+0xfb/0xbc0 drivers/net/netdevsim/dev.c:1583 #6: ffffffff905d6a38 (rtnl_mutex){+.+.}-{4:4}, at: nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1060 [inline] #6: ffffffff905d6a38 (rtnl_mutex){+.+.}-{4:4}, at: nsim_create+0x87f/0x1160 drivers/net/netdevsim/netdev.c:1154 #7: ffff88813ff77238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x41/0x6f0 fs/kernfs/dir.c:825 locks held by syz-executor/21955: 2, on CPU#0: #0: ffffffff8fd13e08 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8fd13e08 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8fd13e08 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:595 #1: ffffffff905d6a38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff905d6a38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline] #1: ffffffff905d6a38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4219 locks held by syz-executor/22015: 2, on CPU#0: #0: ffffffff8fd36108 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8fd36108 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8fd36108 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:595 #1: ffffffff905d6a38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff905d6a38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline] #1: ffffffff905d6a38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4219 locks held by syz.0.1297/22136: 3, last CPU#0: #0: ffff88801beb8510 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2756 [inline] #0: ffff88801beb8510 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff888066398390 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #1: ffff888066398390 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: shmem_file_write_iter+0x82/0x120 mm/shmem.c:3433 #2: ffffffff8f1c3d00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #2: ffffffff8f1c3d00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8f1c3d00 (rcu_read_lock){....}-{1:3}, at: get_mem_cgroup_from_mm+0x38/0x2d0 mm/memcontrol.c:1185 locks held by sed/22146: 2, last CPU#0: #0: ffff888035165948 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310 #1: ffffffff8f1c3d00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8f1c3d00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8f1c3d00 (rcu_read_lock){....}-{1:3}, at: count_memcg_events_mm include/linux/memcontrol.h:990 [inline] #1: ffffffff8f1c3d00 (rcu_read_lock){....}-{1:3}, at: count_memcg_event_mm+0x21/0x260 include/linux/memcontrol.h:1000 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 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:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x38b/0x470 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