INFO: task syz.0.944:10602 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.944 state:D stack:26688 pid:10602 tgid:10600 ppid:10254 task_flags:0x400040 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 user_get_super+0xc8/0x120 fs/super.c:1001 quotactl_block fs/quota/quota.c:889 [inline] __do_sys_quotactl fs/quota/quota.c:955 [inline] __se_sys_quotactl+0x540/0x9e0 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: 0033:0x7f4b4850c799 RSP: 002b:00007f4b4675e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f4b48785fa0 RCX: 00007f4b4850c799 RDX: 0000000000000000 RSI: 0000200000000280 RDI: ffffffff80000701 RBP: 00007f4b485a2c99 R08: 0000000000000000 R09: 0000000000000000 R10: 00002000000005c0 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4b48786038 R14: 00007f4b48785fa0 R15: 00007ffd77f9e0c8 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 5 locks held by kworker/u8:9/1058: 2 locks held by getty/5557: #0: ffff888037d700a0 (&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+0x462/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5812: 4 locks held by syz-executor/7162: 1 lock held by udevd/10586: 1 lock held by syz.0.944/10602: #0: ffff8880339840d0 (&type->s_umount_key#74){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880339840d0 (&type->s_umount_key#74){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 4 locks held by syz.2.1218/12560: 2 locks held by syz.5.1220/12566: 2 locks held by syz.7.1222/12572: 3 locks held by udevadm/12600: 2 locks held by syz.8.1225/12602: 5 locks held by syz.3.1226/12603: 2 locks held by syz.3.1226/12605: 2 locks held by dhcpcd-run-hook/12604: ============================================= 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 02/12/2026 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: 1058 Comm: kworker/u8:9 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline] RIP: 0010:lock_acquire+0x105/0x2e0 kernel/locking/lockdep.c:5870 Code: f8 6a 00 6a 00 6a 00 ff b4 24 88 00 00 00 41 56 e8 80 02 00 00 48 83 c4 28 48 c7 c7 51 d3 7b 8d e8 00 b7 82 09 b8 ff ff ff ff <65> 0f c1 05 d3 4f ae 10 83 f8 01 0f 85 b0 00 00 00 9c 58 a9 00 02 RSP: 0018:ffffc900055af6f0 EFLAGS: 00000002 RAX: 00000000ffffffff RBX: 0000000000000046 RCX: 0000000080000001 RDX: 00000000a6c8a000 RSI: ffffffff8d7bd351 RDI: ffffffff8ba66700 RBP: 0000000000000000 R08: ffffffff8b252147 R09: ffff8880b89370d0 R10: dffffc0000000000 R11: fffffbfff1ed4797 R12: 0000000000000000 R13: ffff8880b89370d0 R14: 0000000000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff88812643c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fee799e14e8 CR3: 0000000082ee8000 CR4: 00000000003526f0 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162 rtlock_slowlock kernel/locking/rtmutex.c:1894 [inline] rtlock_lock kernel/locking/spinlock_rt.c:43 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline] rt_spin_lock+0x157/0x400 kernel/locking/spinlock_rt.c:57 spin_lock include/linux/spinlock_rt.h:45 [inline] crng_make_state+0x162/0x5d0 drivers/char/random.c:361 _get_random_bytes+0xff/0x260 drivers/char/random.c:399 eth_random_addr include/linux/etherdevice.h:238 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:826 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline] nsim_dev_trap_report_work+0x362/0xbc0 drivers/net/netdevsim/dev.c:922 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 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