INFO: task syz.4.1068:17070 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.4.1068 state:D stack:26712 pid:17070 tgid:17069 ppid:15776 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: 0033:0x7f780678ebe9 RSP: 002b:00007f78049ee038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f78069b5fa0 RCX: 00007f780678ebe9 RDX: 0000000000000000 RSI: 00002000000000c0 RDI: ffffffff80000801 RBP: 00007f7806811e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000040 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f78069b6038 R14: 00007f78069b5fa0 R15: 00007ffd0049c028 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: 18729 Comm: syz.5.1241 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:__orc_find arch/x86/kernel/unwind_orc.c:100 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline] RIP: 0010:unwind_next_frame+0x12e3/0x2390 arch/x86/kernel/unwind_orc.c:494 Code: 18 48 8b 10 48 c7 c7 80 42 08 8b 89 de e8 45 8e b4 ff e9 43 06 00 00 49 89 d5 48 89 d5 48 89 d8 48 29 e8 48 89 c1 48 c1 f9 02 <48> c1 e8 3f 48 01 c8 48 83 e0 fe 4c 8d 3c 45 00 00 00 00 49 01 ef RSP: 0018:ffffc90004cff438 EFLAGS: 00000206 RAX: 0000000000000030 RBX: ffffffff8f38ccb8 RCX: 000000000000000c RDX: ffffffff8f38cc88 RSI: ffffffff8fb35a02 RDI: ffffffff8b620c20 RBP: ffffffff8f38cc88 R08: 000000000000000d R09: 0000000000000000 R10: ffffc90004cff558 R11: ffffffff81aae020 R12: ffffffff821d559d R13: ffffffff8f38cc88 R14: ffffc90004cff508 R15: 0000000000011d55 FS: 0000000000000000(0000) GS:ffff8881269c5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9662503000 CR3: 0000000036870000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 __call_rcu_common kernel/rcu/tree.c:3123 [inline] call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3243 slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4680 [inline] kmem_cache_free+0x402/0x510 mm/slub.c:4782 exit_mmap+0x53f/0xb50 mm/mmap.c:1305 __mmput+0xcb/0x3d0 kernel/fork.c:1130 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x2300 kernel/exit.c:949 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 __do_sys_exit_group kernel/exit.c:1113 [inline] __se_sys_exit_group kernel/exit.c:1111 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7f21c0c4ebe9 Code: Unable to access opcode bytes at 0x7f21c0c4ebbf. RSP: 002b:00007fff720c77e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f21c0c4ebe9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fff720c784c R08: 00000003720c78df R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000002c R13: 00000000000927c0 R14: 00000000000ec20c R15: 00007fff720c78a0