INFO: task syz.2.457:11561 blocked for more than 143 seconds. Tainted: G W syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.457 state:D stack:26712 pid:11561 tgid:11560 ppid:10934 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 __rwbase_read_lock+0xbc/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+0x127/0x1f0 kernel/locking/rwsem.c:1539 __super_lock fs/super.c:59 [inline] super_lock+0x2a9/0x3b0 fs/super.c:121 user_get_super+0xc8/0x120 fs/super.c:998 quotactl_block fs/quota/quota.c:890 [inline] __do_sys_quotactl fs/quota/quota.c:955 [inline] __se_sys_quotactl+0x4da/0x950 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8b1baaebe9 RSP: 002b:00007f8b19d0e038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f8b1bcd5fa0 RCX: 00007f8b1baaebe9 RDX: 000000000000ee00 RSI: 0000200000000000 RDI: ffffffff80000901 RBP: 00007f8b1bb31e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8b1bcd6038 R14: 00007f8b1bcd5fa0 R15: 00007ffeb832ef08 INFO: lockdep is turned off. NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Tainted: G W syzkaller #0 PREEMPT_{RT,(full)} Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 14478 Comm: syz.5.793 Tainted: G W syzkaller #0 PREEMPT_{RT,(full)} Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:do_raw_spin_unlock+0x0/0x240 kernel/locking/spinlock_debug.c:139 Code: 80 e1 07 80 c1 03 38 c1 0f 8c 6a ff ff ff e8 77 e0 80 00 e9 60 ff ff ff 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <66> 0f 1f 00 55 41 57 41 56 41 55 41 54 53 48 89 fb 49 bc 00 00 00 RSP: 0018:ffffc9000447f598 EFLAGS: 00000082 RAX: 9ca4823e89e07e00 RBX: 0000000000000a06 RCX: 9ca4823e89e07e00 RDX: 0000000000000001 RSI: ffffffff8b620c60 RDI: ffff8880b893bf40 RBP: ffffc9000447f630 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff5200088fea4 R12: dffffc0000000000 R13: ffff8880b893bf40 R14: ffff8880b893bf40 R15: 1ffff9200088feb4 FS: 00007fe6623766c0(0000) GS:ffff8881269c4000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560613498080 CR3: 000000008af12000 CR4: 00000000003526f0 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_unlock_irqrestore+0x78/0x110 kernel/locking/spinlock.c:194 unlock_rt_mutex_safe kernel/locking/rtmutex.c:344 [inline] rt_mutex_slowunlock+0x493/0x8a0 kernel/locking/rtmutex.c:1454 spin_unlock include/linux/spinlock_rt.h:105 [inline] consume_stock mm/memcontrol.c:1820 [inline] try_charge_memcg+0x3f3/0xf70 mm/memcontrol.c:2314 try_charge mm/memcontrol.c:2499 [inline] charge_memcg+0x9f/0x180 mm/memcontrol.c:4702 __mem_cgroup_charge+0x25/0x80 mm/memcontrol.c:4719 mem_cgroup_charge include/linux/memcontrol.h:654 [inline] shmem_alloc_and_add_folio mm/shmem.c:1957 [inline] shmem_get_folio_gfp+0x74e/0x1a70 mm/shmem.c:2597 shmem_get_folio mm/shmem.c:2703 [inline] shmem_write_begin+0xef/0x2a0 mm/shmem.c:3353 generic_perform_write+0x29a/0x8c0 mm/filemap.c:4175 shmem_file_write_iter+0xfb/0x120 mm/shmem.c:3528 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5d2/0xb40 fs/read_write.c:686 ksys_write+0x14b/0x260 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe66410d69f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48 RSP: 002b:00007fe662375df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000013bd7ef RCX: 00007fe66410d69f RDX: 00000000013bd7ef RSI: 00007fe659f56000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000005516 R10: 00000000000003c8 R11: 0000000000000293 R12: 0000000000000003 R13: 00007fe662375ef0 R14: 00007fe662375eb0 R15: 00007fe659f56000