INFO: task syz.0.389:9029 blocked for more than 163 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.389 state:D stack:29304 pid:9029 tgid:9027 ppid:8226 task_flags:0x400040 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 __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:1502 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1576 __super_lock fs/super.c:60 [inline] super_lock+0x2d6/0x3d0 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: 0033:0x7f5a5c6ece59 RSP: 002b:00007f5a5a925028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f5a5c966090 RCX: 00007f5a5c6ece59 RDX: ffffffffffffffff RSI: 00002000000000c0 RDI: ffffffff80000900 RBP: 00007f5a5c782e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5a5c966128 R14: 00007f5a5c966090 R15: 00007ffe96535978 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: 13241 Comm: syz.6.773 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:___update_load_sum kernel/sched/pelt.c:227 [inline] RIP: 0010:__update_load_avg_se+0x557/0xbd0 kernel/sched/pelt.c:309 Code: b6 6c 24 07 40 84 ed 74 21 c1 e3 0a 4d 8d bc 24 18 01 00 00 4c 89 f8 48 c1 e8 03 0f b6 04 30 84 c0 0f 85 d4 04 00 00 41 01 1f <49> c1 ed 0a 45 85 ed 0f 84 9b 00 00 00 4c 89 e3 4c 89 e0 48 c1 e8 RSP: 0000:ffffc900103d7138 EFLAGS: 00000046 RAX: 1ffff11007ed2412 RBX: 0000000000001595 RCX: 7ffffffffffffc00 RDX: 0000000000565400 RSI: dffffc0000000000 RDI: ffff88803f692098 RBP: 0000000000000000 R08: 000000000000024d R09: 0000000000000000 R10: ffffe8ffffd95798 R11: ffffffff81971450 R12: ffff88803f691f80 R13: 0000000000001a4d R14: 1ffff11007ed2413 R15: ffff88803f692090 FS: 00007ff36c0366c0(0000) GS:ffff88812621d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1d946cefeb CR3: 00000000351e0000 CR4: 00000000003526f0 Call Trace: update_load_avg+0x1ae/0x1950 kernel/sched/fair.c:5652 set_next_entity kernel/sched/fair.c:6338 [inline] set_next_task_fair+0x116/0xce0 kernel/sched/fair.c:15045 put_prev_set_next_task kernel/sched/sched.h:2770 [inline] __pick_next_task+0x215/0x3c0 kernel/sched/core.c:6146 pick_next_task kernel/sched/core.c:-1 [inline] __schedule+0x864/0x5500 kernel/sched/core.c:7143 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7409 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 class_preempt_destructor include/linux/preempt.h:468 [inline] raw_spin_unlock_irqrestore_wake include/linux/sched/wake_q.h:102 [inline] rtlock_slowlock kernel/locking/rtmutex.c:1923 [inline] rtlock_lock kernel/locking/spinlock_rt.c:43 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline] rt_spin_lock+0x316/0x400 kernel/locking/spinlock_rt.c:57 spin_lock include/linux/spinlock_rt.h:45 [inline] folio_lruvec_lock_irqsave+0x293/0x540 mm/memcontrol.c:1464 folio_lruvec_relock_irqsave include/linux/memcontrol.h:1526 [inline] folio_batch_move_lru+0x4ae/0x820 mm/swap.c:199 __folio_batch_add_and_move+0x446/0xa90 mm/swap.c:231 shmem_alloc_and_add_folio mm/shmem.c:2008 [inline] shmem_get_folio_gfp+0xc8a/0x1c40 mm/shmem.c:2502 shmem_get_folio mm/shmem.c:2608 [inline] shmem_write_begin+0x166/0x320 mm/shmem.c:3239 generic_perform_write+0x2ad/0x8b0 mm/filemap.c:4358 shmem_file_write_iter+0xfb/0x120 mm/shmem.c:3414 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61e/0xbb0 fs/read_write.c:687 ksys_write+0x156/0x270 fs/read_write.c:739 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: 0033:0x7ff36dd9d68e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007ff36c035da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ff36c0366c0 RCX: 00007ff36dd9d68e RDX: 00000000013bd7ef RSI: 00007ff363c16000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 00007ff36c035ee0 R14: 00007ff36c035ea0 R15: 00007ff363c16000