INFO: task syz.2.694:13208 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.694 state:D stack:25720 pid:13208 tgid:13207 ppid:12676 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: 0033:0x7f1e86c4ce59 RSP: 002b:00007f1e84ea6028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f1e86ec5fa0 RCX: 00007f1e86c4ce59 RDX: 0000000000000000 RSI: 00002000000001c0 RDI: ffffffff80000302 RBP: 00007f1e86ce2e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1e86ec6038 R14: 00007f1e86ec5fa0 R15: 00007ffe76e19df8 INFO: lockdep is turned off. NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 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: 16410 Comm: udevadm Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:debug_lockdep_rcu_enabled+0xd/0x40 kernel/rcu/update.c:320 Code: 8d 67 48 0f b9 3a 90 eb ca cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 31 c0 83 3d 63 29 68 04 00 <74> 1d 83 3d 7a 3b 68 04 00 74 14 65 48 8b 0d 38 45 4c 07 31 c0 83 RSP: 0018:ffffc9000623f558 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffffc9000623f618 RCX: ffffc9000623fdc8 RDX: ffffc9000623f601 RSI: dffffc0000000000 RDI: ffffc9000623f610 RBP: 1ffffffff204d901 R08: ffffc9000623fdb0 R09: 0000000000000000 R10: ffffc9000623f658 R11: fffff52000c47ecd R12: ffffc90006238000 R13: ffffffff8176a1ff R14: ffffc9000623f608 R15: ffffc9000623fdc0 FS: 00007f94edbd9880(0000) GS:ffff888126242000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055559e3ae5f8 CR3: 000000008c4c6000 CR4: 00000000003526f0 Call Trace: rcu_read_unlock include/linux/rcupdate.h:869 [inline] class_rcu_destructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0x1b5d/0x2550 arch/x86/kernel/unwind_orc.c:709 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4612 [inline] slab_alloc_node mm/slub.c:4945 [inline] kmem_cache_alloc_noprof+0x355/0x650 mm/slub.c:4959 alloc_empty_file+0x5b/0x1d0 fs/file_table.c:262 path_openat+0x8f/0x3850 fs/namei.c:4845 do_file_open+0x23e/0x4a0 fs/namei.c:4888 do_sys_openat2+0x115/0x200 fs/open.c:1395 do_sys_open fs/open.c:1401 [inline] __do_sys_openat fs/open.c:1417 [inline] __se_sys_openat fs/open.c:1412 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1412 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: 0033:0x7f94edcc7407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffc38f5d760 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f94edbd9880 RCX: 00007f94edcc7407 RDX: 0000000000080000 RSI: 00007ffc38f5d8d0 RDI: ffffffffffffff9c RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055557d03bee0 R13: 000055557d03bee0 R14: 0000000000000001 R15: 000055559e3abe60