INFO: task syz.1.802:8904 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.802 state:D stack:28056 pid:8904 tgid:8898 ppid:6342 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x169e/0x54f0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 super_lock+0x1e0/0x3d0 fs/super.c:116 __iterate_supers+0x126/0x250 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+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f23240ea679 RSP: 002b:00007f232374e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f2324355fa0 RCX: 00007f23240ea679 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007f232417dee0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2324356038 R14: 00007f2324355fa0 R15: 00007ffd562f9c68 INFO: task syz.2.804:8903 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.804 state:D stack:26880 pid:8903 tgid:8901 ppid:6343 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x169e/0x54f0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 super_lock+0x1e0/0x3d0 fs/super.c:116 __iterate_supers+0x126/0x250 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+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe41d7ca679 RSP: 002b:00007fe41ce2e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007fe41da35fa0 RCX: 00007fe41d7ca679 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007fe41d85dee0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe41da36038 R14: 00007fe41da35fa0 R15: 00007ffe5de16488 INFO: task syz.0.805:8908 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.805 state:D stack:26880 pid:8908 tgid:8907 ppid:6338 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x169e/0x54f0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 super_lock+0x1e0/0x3d0 fs/super.c:116 __iterate_supers+0x126/0x250 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+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2477a0a679 RSP: 002b:00007f247706e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f2477c75fa0 RCX: 00007f2477a0a679 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007f2477a9dee0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2477c76038 R14: 00007f2477c75fa0 R15: 00007ffc878b6cc8 INFO: task syz.3.806:8912 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.806 state:D stack:25688 pid:8912 tgid:8911 ppid:6345 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x169e/0x54f0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 super_lock+0x1e0/0x3d0 fs/super.c:116 __iterate_supers+0x126/0x250 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+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6c4bafa679 RSP: 002b:00007f6c4b15e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f6c4bd65fa0 RCX: 00007f6c4bafa679 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007f6c4bb8dee0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6c4bd66038 R14: 00007f6c4bd65fa0 R15: 00007fff5dc3acd8 Showing all locks held in the system: 3 locks held by kworker/0:1/10: #0: ffff88813fe47938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x890/0x1710 kernel/workqueue.c:3284 #1: ffffc900000f7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x1710 kernel/workqueue.c:3285 #2: ffff888052795260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x222/0x3e0 drivers/net/netdevsim/fib.c:1490 5 locks held by ktimers/0/16: #0: ffffffff8e25f280 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #1: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #2: ffff8880b8624368 (tasklet_sync_callback.cb_lock){+...}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffff8880b8624368 (tasklet_sync_callback.cb_lock){+...}-{3:3}, at: tasklet_lock_callback kernel/softirq.c:881 [inline] #2: ffff8880b8624368 (tasklet_sync_callback.cb_lock){+...}-{3:3}, at: tasklet_action_common+0xb6/0x540 kernel/softirq.c:931 #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #4: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #4: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #4: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: netif_receive_skb_list_internal+0x501/0xcf0 net/core/dev.c:6428 1 lock held by khungtaskd/39: #0: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777 3 locks held by kworker/u8:6/150: #0: ffff888033169138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x890/0x1710 kernel/workqueue.c:3284 #1: ffffc90003aa7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x1710 kernel/workqueue.c:3285 #2: ffffffff8f7a2b38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f7a2b38 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4206 3 locks held by kworker/u8:8/1030: #0: ffff88801ae84138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x890/0x1710 kernel/workqueue.c:3284 #1: ffffc900050cfc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x8b7/0x1710 kernel/workqueue.c:3285 #2: ffffffff8f7a2b38 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 2 locks held by getty/5578: #0: ffff88803855b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:4/5935: #0: ffff88813fe47938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x890/0x1710 kernel/workqueue.c:3284 #1: ffffc90003db7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x1710 kernel/workqueue.c:3285 #2: ffff88802b5df260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x222/0x3e0 drivers/net/netdevsim/fib.c:1490 1 lock held by syz.1.802/8906: #0: ffff888036c420d0 (&type->s_umount_key#75/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 1 lock held by syz-executor/9391: #0: ffffffff8f7a2b38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f7a2b38 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5039 1 lock held by syz-executor/9398: #0: ffffffff8f7a2b38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f7a2b38 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978 ============================================= 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 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:162 [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+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 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 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:preempt_count kernel/rcu/tree.c:4033 [inline] RIP: 0010:rcu_lockdep_current_cpu_online+0x8/0x120 kernel/rcu/tree.c:4037 Code: df e9 4e ff ff ff 66 66 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 f3 0f 1e fa 41 57 41 56 <53> 65 8b 0d 60 9c 11 11 b0 01 f7 c1 00 00 f0 00 0f 85 d5 00 00 00 RSP: 0018:ffffc90000157118 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000080000001 RDX: 0000000000000100 RSI: ffffffff8bca5b40 RDI: ffffffff8bca5b00 RBP: ffffc90000157298 R08: 0000000000000000 R09: 0000000000000100 R10: ffffc90000157220 R11: fffff5200002ae46 R12: 1ffff1100ca5500c R13: dffffc0000000000 R14: ffff888066fbb400 R15: ffffc90000157398 FS: 0000000000000000(0000) GS:ffff888125a62000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa19ddf2e9c CR3: 000000002aaba000 CR4: 00000000003526f0 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:113 [inline] rcu_read_lock_held+0x1e/0x50 kernel/rcu/update.c:349 __find_rr_leaf+0x353/0x760 net/ipv6/route.c:833 find_rr_leaf net/ipv6/route.c:889 [inline] rt6_select net/ipv6/route.c:933 [inline] fib6_table_lookup+0x3b5/0xa80 net/ipv6/route.c:2247 ip6_pol_route+0x228/0x13e0 net/ipv6/route.c:2283 pol_lookup_func include/net/ip6_fib.h:667 [inline] fib6_rule_lookup+0x563/0x740 net/ipv6/fib6_rules.c:123 ip6_route_input_lookup net/ipv6/route.c:2352 [inline] ip6_route_input+0x730/0xad0 net/ipv6/route.c:2655 ip6_rcv_finish+0x141/0x280 net/ipv6/ip6_input.c:117 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6210 [inline] __netif_receive_skb net/core/dev.c:6323 [inline] process_backlog+0x3ce/0xc60 net/core/dev.c:6674 __napi_poll+0xab/0x550 net/core/dev.c:7738 napi_poll net/core/dev.c:7801 [inline] net_rx_action+0x696/0xe00 net/core/dev.c:7958 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] run_ktimerd+0x69/0x100 kernel/softirq.c:1155 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x388/0x470 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