syzbot

INFO: task syz.3.573:11446 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.573       state:D stack:26008 pid:11446 tgid:11445 ppid:10987  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: 0033:0x7f56b2dfce59
RSP: 002b:00007f56b104e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f56b3075fa0 RCX: 00007f56b2dfce59
RDX: 0000000000000000 RSI: 00002000000003c0 RDI: ffffffff80000800
RBP: 00007f56b2e92e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000540 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f56b3076038 R14: 00007f56b3075fa0 R15: 00007fffb0e21c58
 </TASK>
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:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 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: 15444 Comm: syz.1.854 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x3a/0xb0 kernel/rcu/tree.c:752
Code: e8 ab 9c 77 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd d0 47 8d 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 fc 94 84 00 48 c7 c3 58 fd 6e 92 49 03 1e 48 89
RSP: 0000:ffffc9000e80f9e0 EFLAGS: 00000046
RAX: 1ffffffff1b1a8fb RBX: 0000000000000001 RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8ba7ef80 RDI: ffffffff8ba7ef40
RBP: ffff888035e75100 R08: ffffffff8f89bbf7 R09: 1ffffffff1f1377e
R10: dffffc0000000000 R11: fffffbfff1f1377f R12: 0000000000000001
R13: ffff888035e75dc0 R14: ffffffff8d8d47d8 R15: dffffc0000000000
FS:  00007f84f8fd66c0(0000) GS:ffff888126244000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f84f0bce028 CR3: 00000000603ce000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 trace_irq_enable+0x3b/0x140 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x18/0x40 kernel/trace/trace_preemptirq.c:73
 flush_tlb_mm_range+0xa7a/0x1090 arch/x86/mm/tlb.c:1457
 flush_tlb_page arch/x86/include/asm/tlbflush.h:345 [inline]
 ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:104
 wp_page_copy mm/memory.c:3941 [inline]
 do_wp_page+0x23bd/0x3d90 mm/memory.c:4336
 handle_pte_fault mm/memory.c:6395 [inline]
 __handle_mm_fault mm/memory.c:6517 [inline]
 handle_mm_fault+0xa03/0x13f0 mm/memory.c:6686
 do_user_addr_fault+0xa4d/0x1340 arch/x86/mm/fault.c:1343
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7f84fac34123
Code: 1f 84 00 00 00 00 00 3d 00 01 00 00 75 29 45 31 f6 48 83 c4 18 44 89 f0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 0f 1f 40 00 49 8b 0f <44> 88 34 01 49 83 47 10 01 eb 92 66 90 8d 90 ff fe ff ff 83 fa 1c
RSP: 002b:00007f84f8fd5470 EFLAGS: 00010202
RAX: 0000000000018028 RBX: 00007f84f8fd5530 RCX: 00007f84f0bb6000
RDX: 00007f84f8fd56d0 RSI: 0000000000000000 RDI: 00007f84f8fd55d0
RBP: 000000000000009d R08: 0000000000000006 R09: 0000000000000021
R10: 0000000000000028 R11: 00007f84f8fd5530 R12: 0000000000000001
R13: 00007f84fae32aa0 R14: 0000000000000001 R15: 00007f84f8fd55d0
 </TASK>