INFO: task syz.7.178:7357 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.178 state:D stack:25096 pid:7357 tgid:7356 ppid:7054 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 __rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1466 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1539 __super_lock fs/super.c:60 [inline] super_lock+0x2d6/0x3d0 fs/super.c:122 __iterate_supers+0x126/0x290 fs/super.c:926 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:938 [inline] __se_sys_quotactl+0x3a7/0x9e0 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7e84f4c819 RSP: 002b:00007f7e8319e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f7e851c5fa0 RCX: 00007f7e84f4c819 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000100 RBP: 00007f7e84fe2c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7e851c6038 R14: 00007f7e851c5fa0 R15: 00007fffd11eb168 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:8/1144: #0: ffff8880321a3938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff8880321a3938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90005ac7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90005ac7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f15cc38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f15cc38 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4198 2 locks held by kworker/u8:9/1230: #0: ffff888019c44938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90005d67c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90005d67c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 3 locks held by kworker/1:3/1239: #0: ffff888019c07938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c07938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90005db7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90005db7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffff88802ba87260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x222/0x3e0 drivers/net/netdevsim/fib.c:1490 7 locks held by udevd/5163: 2 locks held by dhcpcd/5458: 2 locks held by getty/5555: #0: ffff8880377d70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5797: 1 lock held by udevd/5848: #0: ffff8880620f1a08 (&ep->lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:96 [inline] #0: ffff8880620f1a08 (&ep->lock){+.+.}-{3:3}, at: ep_poll fs/eventpoll.c:2040 [inline] #0: ffff8880620f1a08 (&ep->lock){+.+.}-{3:3}, at: do_epoll_wait+0x851/0xbd0 fs/eventpoll.c:2462 1 lock held by udevd/5861: 1 lock held by syz.7.178/7357: #0: ffff888036db80d0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888036db80d0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 3 locks held by kworker/u8:12/7890: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc900061e7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc900061e7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f15cc38 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 1 lock held by syz.8.312/8256: #0: ffff888036db80d0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888036db80d0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.8.312/8264: #0: ffff888036db80d0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888036db80d0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.5.361/8684: #0: ffff888036db80d0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888036db80d0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.5.361/8709: #0: ffff888036db80d0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888036db80d0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 3 locks held by syz.2.378/8816: #0: ffff88803d343b28 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1261 #1: ffff888029940480 (sb_writers#3){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #1: ffff888029940480 (sb_writers#3){.+.+}-{0:0}, at: vfs_writev+0x2b0/0x9a0 fs/read_write.c:1057 #2: ffff888036db80d0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #2: ffff888036db80d0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz-executor/8831: #0: ffffffff8f15cc38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f15cc38 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978 3 locks held by syz-executor/8848: #0: ffffffff8f15cc38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f15cc38 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978 #1: ffffffff8f23fc80 ((inetaddr_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x54/0x90 kernel/notifier.c:379 #2: ffff88813fe18758 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffff88813fe18758 (&n->list_lock){+.+.}-{3:3}, at: get_partial_node_bulk mm/slub.c:3750 [inline] #2: ffff88813fe18758 (&n->list_lock){+.+.}-{3:3}, at: __refill_objects_node+0x87/0x560 mm/slub.c:7027 6 locks held by syz-executor/8966: 1 lock held by modprobe/9147: ============================================= 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 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 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: 9147 Comm: modprobe Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:enqueue_task_rt+0xe/0xd20 kernel/sched/rt.c:1432 Code: 41 5e 41 5f 5d e9 82 34 8e 09 cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 <48> 83 ec 40 89 d5 49 89 f5 49 bf 00 00 00 00 00 fc ff df 40 f6 c5 RSP: 0018:ffffc90000a78e68 EFLAGS: 00000046 RAX: 1ffffffff1afec22 RBX: ffff88801d2bbd00 RCX: 0000000080000004 RDX: 0000000000000009 RSI: ffff88801d2bbd00 RDI: ffff8880b893b780 RBP: 0000000000000009 R08: ffffffff8f6a6db7 R09: 1ffffffff1ed4db6 R10: dffffc0000000000 R11: ffffffff81998e30 R12: ffff8880b893b780 R13: dffffc0000000000 R14: ffff8880b893b780 R15: ffffffff8d7f6110 FS: 0000000000000000(0000) GS:ffff888126435000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc0c688d3c CR3: 00000000699da000 CR4: 00000000003526f0 Call Trace: enqueue_task+0x75/0x410 kernel/sched/core.c:2107 activate_task kernel/sched/core.c:2147 [inline] ttwu_do_activate+0x1cc/0x660 kernel/sched/core.c:3667 ttwu_queue kernel/sched/core.c:3918 [inline] try_to_wake_up+0x724/0x1380 kernel/sched/core.c:4242 wake_timersd kernel/softirq.c:704 [inline] __irq_exit_rcu+0xb7/0x180 kernel/softirq.c:727 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:194 Code: f7 e8 bd 6e 79 f6 f7 c3 00 02 00 00 74 05 e8 70 eb a4 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 94 3b 6c f6 65 8b 05 dd 29 27 07 85 c0 74 18 5b 41 5e e9 41 3c RSP: 0018:ffffc90005897660 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000296 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8d564e3e RDI: 0000000000000001 RBP: 0000000000000000 R08: ffffffff8f6a6db7 R09: 1ffffffff1ed4db6 R10: dffffc0000000000 R11: fffffbfff1ed4db7 R12: ffff88804125e780 R13: ffff88804125e770 R14: ffffffff9981d190 R15: 1ffff1100824bcf0 debug_object_activate+0x314/0x520 lib/debugobjects.c:853 debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline] __call_rcu_common kernel/rcu/tree.c:3116 [inline] call_rcu+0x43/0x890 kernel/rcu/tree.c:3251 slab_free_hook mm/slub.c:2649 [inline] slab_free mm/slub.c:6165 [inline] kmem_cache_free+0x50e/0x6b0 mm/slub.c:6295 __fput_deferred+0x2df/0x3e0 fs/file_table.c:524 fput_close+0x11f/0x240 fs/file_table.c:586 path_openat+0x3161/0x38a0 fs/namei.c:4845 do_file_open+0x23e/0x4a0 fs/namei.c:4865 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4d29db80ba Code: 41 89 f2 48 89 54 24 e0 41 83 e2 40 75 2a 89 f0 f7 d0 a9 00 00 41 00 74 1f 89 f2 b8 01 01 00 00 48 89 fe bf 9c ff ff ff 0f 05 <48> 3d 00 f0 ff ff 77 2e c3 0f 1f 44 00 00 48 8d 44 24 08 c7 44 24 RSP: 002b:00007ffc0c688b18 EFLAGS: 00000206 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffc0c688b90 RCX: 00007f4d29db80ba RDX: 0000000000080000 RSI: 00007ffc0c688b90 RDI: 00000000ffffff9c RBP: 00007ffc0c688b80 R08: 00007ffc0c688d87 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000033 R13: 00007f4d29d8c000 R14: 00007ffc0c688da0 R15: 0000000000000000