INFO: task syz.1.1645:17435 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1645      state:D stack:24328 pid:17435 tgid:17433 ppid:1[  862.663683][   T38] task:syz.1.1645      state:D stack:24328 pid:17435 tgid:17433 ppid:15919  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 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: 0033:0x7fe3e954ce59
RSP: 002b:00007fe3e779e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fe3e97c5fa0 RCX: 00007fe3e954ce59
RDX: 0000000000000000 RSI: 0000200000000340 RDI: ffffffff80000800
RBP: 00007fe3e95e2e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000080 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe3e97c6038 R14: 00007fe3e97c5fa0 R15: 00007fff7f0e1c68
 </TASK>
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:
 <TASK>
 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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 20088 Comm: syz.4.1915 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:css_rstat_cpu kernel/cgroup/rstat.c:32 [inline]
RIP: 0010:__css_rstat_updated+0x1a7/0x540 kernel/cgroup/rstat.c:90
Code: 86 07 00 eb 20 65 44 8b 25 ee ae b0 10 31 ff 44 89 e6 e8 9c 8a 07 00 45 85 e4 0f 85 ae 02 00 00 e8 de 85 07 00 4c 89 6c 24 20 <49> 83 c7 20 4c 89 f8 48 c1 e8 03 42 80 3c 30 00 74 08 4c 89 ff e8
RSP: 0018:ffffc90005c9f5e0 EFLAGS: 00000283
RAX: ffffffff81bd7161 RBX: ffff888040212000 RCX: 0000000000080000
RDX: ffffc9000e729000 RSI: 0000000000033cdf RDI: 0000000000033ce0
RBP: ffffc90005c9f6c8 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f1383f R12: 0000000000000000
R13: 1ffff92000b93ec4 R14: dffffc0000000000 R15: ffff888062073d00
FS:  00007fa31d7266c0(0000) GS:ffff888126242000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f463d654000 CR3: 0000000025a6e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 memcg_rstat_updated+0x2e/0x200 mm/memcontrol.c:682
 __mod_memcg_lruvec_state+0x18d/0x360 mm/memcontrol.c:931
 mod_memcg_lruvec_state+0x1e7/0x270 mm/memcontrol.c:950
 mod_lruvec_state mm/memcontrol.c:973 [inline]
 lruvec_stat_mod_folio+0x239/0x3e0 mm/memcontrol.c:993
 shmem_update_stats mm/shmem.c:874 [inline]
 shmem_add_to_page_cache+0x900/0xc10 mm/shmem.c:925
 shmem_alloc_and_add_folio mm/shmem.c:1975 [inline]
 shmem_get_folio_gfp+0x8b2/0x1c40 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:4363
 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: 0033:0x7fa31f48d68e
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 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007fa31d725da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa31d7266c0 RCX: 00007fa31f48d68e
RDX: 0000000000200000 RSI: 00007fa315306000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007fa31d725ee0 R14: 00007fa31d725ea0 R15: 00007fa315306000
 </TASK>