INFO: task syz.1.348:8639 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.348 state:D stack:26008 pid:8639 tgid:8637 ppid:8059 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7228 __schedule_loop kernel/sched/core.c:7307 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7603 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1670 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline] __rt_mutex_slowlock_locked+0x1f84/0x25b0 kernel/locking/rtmutex.c:1787 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1827 __rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline] rwbase_write_lock+0x14c/0x720 kernel/locking/rwbase_rt.c:251 __super_lock fs/super.c:58 [inline] super_lock+0x289/0x3d0 fs/super.c:122 user_get_super+0xc8/0x120 fs/super.c:941 quotactl_block fs/quota/quota.c:889 [inline] __do_sys_quotactl fs/quota/quota.c:955 [inline] __se_sys_quotactl+0x538/0x9a0 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f124ce9ce59 RSP: 002b:00007f124b0ee028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f124d115fa0 RCX: 00007f124ce9ce59 RDX: 0000000000000000 RSI: 0000200000000000 RDI: ffffffff80000200 RBP: 00007f124cf32e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000040 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f124d116038 R14: 00007f124d115fa0 R15: 00007ffd2fbd2928 INFO: task syz.1.348:8642 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.348 state:D stack:26008 pid:8642 tgid:8637 ppid:8059 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7228 __schedule_loop kernel/sched/core.c:7307 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7603 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1670 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline] __rt_mutex_slowlock_locked+0x1f84/0x25b0 kernel/locking/rtmutex.c:1787 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1827 __rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline] rwbase_write_lock+0x14c/0x720 kernel/locking/rwbase_rt.c:251 __super_lock fs/super.c:58 [inline] super_lock+0x289/0x3d0 fs/super.c:122 user_get_super+0xc8/0x120 fs/super.c:941 quotactl_block fs/quota/quota.c:889 [inline] __do_sys_quotactl fs/quota/quota.c:955 [inline] __se_sys_quotactl+0x538/0x9a0 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f124ce9ce59 RSP: 002b:00007f124b0cd028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f124d116090 RCX: 00007f124ce9ce59 RDX: 0000000000000000 RSI: 0000200000000080 RDI: ffffffff80000200 RBP: 00007f124cf32e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f124d116128 R14: 00007f124d116090 R15: 00007ffd2fbd2928 INFO: lockdep is turned off. 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 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 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+0xfd7/0x1030 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 10862 Comm: kworker/u8:14 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: kvfree_rcu_reclaim kfree_rcu_work RIP: 0010:_raw_spin_lock_irqsave+0x4c/0x60 kernel/locking/spinlock.c:166 Code: 6a f6 49 8d 7e 18 31 f6 31 d2 31 c9 41 b8 01 00 00 00 45 31 c9 ff 74 24 10 e8 50 84 77 f6 48 83 c4 08 4c 89 f7 e8 24 3d 78 f6 <48> 89 d8 5b 41 5e e9 d9 3d 00 00 cc 0f 1f 84 00 00 00 00 00 90 90 RSP: 0018:ffffc9000e81f9c0 EFLAGS: 00000046 RAX: 44827c8e20cb8a00 RBX: 0000000000000292 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc9000e81f940 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52001d03f28 R12: ffffffff99ab6fd8 R13: ffff88802b9e9600 R14: ffffffff99ab6fe0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff88812621d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f328a959000 CR3: 0000000039246000 CR4: 00000000003526f0 Call Trace: debug_object_active_state+0xa4/0x260 lib/debugobjects.c:1101 debug_rcu_head_unqueue kernel/rcu/rcu.h:245 [inline] debug_rcu_bhead_unqueue mm/slab_common.c:1418 [inline] kvfree_rcu_bulk+0x4b/0x190 mm/slab_common.c:1495 kfree_rcu_work+0xe8/0x160 mm/slab_common.c:1580 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 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