syzbot

INFO: task syz.8.3605:28109 blocked for more than 143 seconds.
      Not tainted 6.17.0-rc1-next-20250814-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.3605      state:D stack:21896 pid:28109 tgid:28094 ppid:27637  task_flags:0x440140 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 rpc_wait_bit_killable+0x5d/0x1c0 net/sunrpc/sched.c:281
 __wait_on_bit+0xb9/0x310 kernel/sched/wait_bit.c:52
 out_of_line_wait_on_bit+0x123/0x170 kernel/sched/wait_bit.c:67
 __rpc_execute+0x742/0x1290 net/sunrpc/sched.c:987
 rpc_execute+0x1d2/0x3a0 net/sunrpc/sched.c:1025
 rpc_run_task+0x4f5/0x690 net/sunrpc/clnt.c:1242
 rpc_call_sync+0xf9/0x1d0 net/sunrpc/clnt.c:1271
 rpcb_register_call net/sunrpc/rpcb_clnt.c:412 [inline]
 rpcb_register+0x2d4/0x530 net/sunrpc/rpcb_clnt.c:476
 __svc_unregister net/sunrpc/svc.c:1205 [inline]
 svc_unregister+0x22a/0x760 net/sunrpc/svc.c:1234
 svc_rpcb_setup net/sunrpc/svc.c:430 [inline]
 svc_bind+0x1e9/0x230 net/sunrpc/svc.c:463
 nfsd_create_serv+0x541/0x840 fs/nfsd/nfssvc.c:642
 nfsd_nl_listener_set_doit+0x13f/0x1690 fs/nfsd/nfsctl.c:1921
 genl_family_rcv_msg_doit+0x212/0x300 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:729
 ____sys_sendmsg+0x505/0x830 net/socket.c:2614
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
 __sys_sendmsg net/socket.c:2700 [inline]
 __do_sys_sendmsg net/socket.c:2705 [inline]
 __se_sys_sendmsg net/socket.c:2703 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
 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: 0033:0x7fd517d8ebe9
RSP: 002b:00007fd515fb4038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fd517fb6180 RCX: 00007fd517d8ebe9
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 000000000000000c
RBP: 00007fd517e11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd517fb6218 R14: 00007fd517fb6180 R15: 00007ffc5d6a6958
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.17.0-rc1-next-20250814-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 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:332 [inline]
 watchdog+0xf60/0xfa0 kernel/hung_task.c:495
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 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: 5917 Comm: kworker/1:4 Not tainted 6.17.0-rc1-next-20250814-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events drain_vmap_area_work
RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:80 [inline]
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:102 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
RIP: 0010:unwind_next_frame+0x1310/0x2390 arch/x86/kernel/unwind_orc.c:494
Code: 3f 48 01 c8 48 83 e0 fe 4c 8d 3c 45 00 00 00 00 49 01 ef 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 <75> 27 49 63 07 4c 01 f8 49 8d 4f 04 4c 39 e0 48 0f 46 e9 49 8d 47
RSP: 0018:ffffc900049a72f8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff8fc064f4 RCX: dffffc0000000000
RDX: ffffffff8fc064d8 RSI: ffffffff9040cfe0 RDI: ffffffff8be34ba0
RBP: ffffffff8fc064d8 R08: 0000000000000011 R09: 0000000000000000
R10: ffffc900049a7418 R11: ffffffff81ac38c0 R12: ffffffff82232bb1
R13: ffffffff8fc064d8 R14: ffffc900049a73c8 R15: ffffffff8fc064e4
FS:  0000000000000000(0000) GS:ffff888125d0f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055bae1731238 CR3: 0000000062f8e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 save_stack+0xf5/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895
 kasan_depopulate_vmalloc_pte+0x74/0xa0 mm/kasan/shadow.c:472
 apply_to_pte_range mm/memory.c:3143 [inline]
 apply_to_pmd_range mm/memory.c:3187 [inline]
 apply_to_pud_range mm/memory.c:3223 [inline]
 apply_to_p4d_range mm/memory.c:3259 [inline]
 __apply_to_page_range+0xb8f/0x1380 mm/memory.c:3295
 kasan_release_vmalloc+0xa2/0xd0 mm/kasan/shadow.c:593
 kasan_release_vmalloc_node mm/vmalloc.c:2249 [inline]
 purge_vmap_node+0x214/0x8f0 mm/vmalloc.c:2266
 __purge_vmap_area_lazy+0x7a4/0xb40 mm/vmalloc.c:2356
 drain_vmap_area_work+0x27/0x40 mm/vmalloc.c:2390
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>