[syzbot] [nfs?] INFO: task hung in nfsd_nl_rpc_status_get_dumpit

[syzbot <syzbot+68f089d6e18e8b1d41eb@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    d7e78951a8b8 Merge tag 'net-6.11-rc0' of git://git.kernel...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=139afe79980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a4420b8b2270c1b1
dashboard link: https://syzkaller.appspot.com/bug?extid=68f089d6e18e8b1d41eb
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7f08d7d67259/disk-d7e78951.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b8fd351d830d/vmlinux-d7e78951.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1bb4a3d18f9e/bzImage-d7e78951.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+68f089d6e18e8b1d41eb@syzkaller.appspotmail.com

INFO: task syz.4.464:6984 blocked for more than 144 seconds.
      Not tainted 6.10.0-syzkaller-09703-gd7e78951a8b8 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.464       state:D stack:26160 pid:6984  tgid:6982  ppid:5094   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0xe37/0x5490 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6621
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752
 nfsd_nl_rpc_status_get_dumpit+0xb1/0x1160 fs/nfsd/nfsctl.c:1550
 genl_dumpit+0x11c/0x220 net/netlink/genetlink.c:1027
 netlink_dump+0x552/0xcc0 net/netlink/af_netlink.c:2325
 __netlink_dump_start+0x6d9/0x9b0 net/netlink/af_netlink.c:2440
 genl_family_rcv_msg_dumpit+0x1e1/0x2e0 net/netlink/genetlink.c:1076
 genl_family_rcv_msg net/netlink/genetlink.c:1192 [inline]
 genl_rcv_msg+0x470/0x800 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2550
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
 netlink_unicast+0x544/0x830 net/netlink/af_netlink.c:1357
 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0xab5/0xc90 net/socket.c:2597
 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2651
 __sys_sendmsg+0x117/0x1f0 net/socket.c:2680
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff23e775b59
RSP: 002b:00007ff23f596048 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff23e905f60 RCX: 00007ff23e775b59
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 000000000000000c
RBP: 00007ff23e7e4e5d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007ff23e905f60 R15: 00007ffdc08a1768
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8dbb29a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:327 [inline]
 #0: ffffffff8dbb29a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:839 [inline]
 #0: ffffffff8dbb29a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6620
3 locks held by kworker/u8:3/52:
3 locks held by kworker/u8:4/62:
 #0: ffff888029d7b948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206
 #1: ffffc900015d7d80 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1b40 kernel/workqueue.c:3207
 #2: ffffffff8f763ce8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcf/0x1500 net/ipv6/addrconf.c:4194
3 locks held by kworker/1:2/928:
 #0: ffff888015480948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206
 #1: ffffc90003c7fd80 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1b40 kernel/workqueue.c:3207
 #2: ffff88802d224240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x1bb/0x26e0 drivers/net/netdevsim/fib.c:1489
2 locks held by kworker/u8:9/2475:
 #0: 
ffff8880b923ec98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:568 [inline]
ffff8880b923ec98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:553
 #1: ffff8880b9228a48 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2d9/0x900 kernel/sched/psi.c:989
2 locks held by getty/4849:
 #0: ffff88802f1020a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: 
ffffc900031232f0
 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2211
4 locks held by kworker/1:3/5137:
 #0: ffff8880b923ec98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:568 [inline]
 #0: ffff8880b923ec98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:553
 #1: ffff8880b9328a48 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2d9/0x900 kernel/sched/psi.c:989
 #2: ffffffff8dbb29a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:327 [inline]
 #2: ffffffff8dbb29a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:839 [inline]
 #2: ffffffff8dbb29a0 (rcu_read_lock){....}-{1:2}, at: check_lifetime+0x73/0xab0 net/ipv4/devinet.c:719
 #3: ffffffff94dea408 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x199/0x540 lib/debugobjects.c:709
2 locks held by syz.0.392/6658:
 #0: ffffffff8f801330 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffffffff8dfb7fe8 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nl_listener_set_doit+0xe3/0x1b30 fs/nfsd/nfsctl.c:1956
3 locks held by syz.4.464/6984:
 #0: ffffffff8f801330 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffff888078416678 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: __netlink_dump_start+0x154/0x9b0 net/netlink/af_netlink.c:2404
 #2: ffffffff8dfb7fe8 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nl_rpc_status_get_dumpit+0xb1/0x1160 fs/nfsd/nfsctl.c:1550
3 locks held by syz.3.482/7069:
 #0: ffffffff8f801330 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffff888065de7678 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: __netlink_dump_start+0x154/0x9b0 net/netlink/af_netlink.c:2404
 #2: ffffffff8dfb7fe8 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nl_rpc_status_get_dumpit+0xb1/0x1160 fs/nfsd/nfsctl.c:1550
3 locks held by syz.1.578/7517:
 #0: ffffffff8f801330 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffff888063317678 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: __netlink_dump_start+0x154/0x9b0 net/netlink/af_netlink.c:2404
 #2: ffffffff8dfb7fe8 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nl_rpc_status_get_dumpit+0xb1/0x1160 fs/nfsd/nfsctl.c:1550
3 locks held by syz.3.733/8134:
 #0: ffffffff8f801330 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffff888060faa678 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: __netlink_dump_start+0x154/0x9b0 net/netlink/af_netlink.c:2404
 #2: ffffffff8dfb7fe8 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nl_rpc_status_get_dumpit+0xb1/0x1160 fs/nfsd/nfsctl.c:1550
3 locks held by syz.0.772/8293:
 #0: ffffffff8f801330 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffff88801f9c1678 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: __netlink_dump_start+0x154/0x9b0 net/netlink/af_netlink.c:2404
 #2: ffffffff8dfb7fe8 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nl_rpc_status_get_dumpit+0xb1/0x1160 fs/nfsd/nfsctl.c:1550
3 locks held by syz-executor/8376:
 #0: ffffffff8f763ce8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8f763ce8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x372/0xea0 net/core/rtnetlink.c:6644
 #1: ffff888023ff5428 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_open+0x203/0x4e0 drivers/net/wireguard/device.c:50
 #2: ffffffff8dbbe138 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:296
1 lock held by syz.3.811/8466:
 #0: ffffffff8dbbe000 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x6c0 kernel/rcu/tree.c:4486

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 30 Comm: khungtaskd Not tainted 6.10.0-syzkaller-09703-gd7e78951a8b8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xf86/0x1240 kernel/hung_task.c:379
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.10.0-syzkaller-09703-gd7e78951a8b8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
RIP: 0010:debug_spin_lock_before kernel/locking/spinlock_debug.c:88 [inline]
RIP: 0010:do_raw_spin_lock+0xe2/0x2c0 kernel/locking/spinlock_debug.c:115
Code: 65 48 8b 05 d0 3a 9b 7e 48 39 c2 0f 84 61 01 00 00 4c 8d 63 08 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 0f b6 14 02 <4c> 89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 68 01 00 00 8b
RSP: 0018:ffffc90000157890 EFLAGS: 00000802
RAX: dffffc0000000000 RBX: ffff888019b44600 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8b2cb840 RDI: ffff888019b44604
RBP: 1ffff9200002af13 R08: 0000000000000000 R09: fffffbfff2856a82
R10: ffffffff942b5417 R11: 0000000000000000 R12: ffff888019b44608
R13: ffff888019b44610 R14: ffff888019b44600 R15: 0100000000000004
FS:  0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f9e2ff8 CR3: 000000007d8d6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0x42/0x60 kernel/locking/spinlock.c:162
 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline]
 try_to_wake_up+0x9a/0x13e0 kernel/sched/core.c:4051
 swake_up_locked kernel/sched/swait.c:29 [inline]
 swake_up_locked kernel/sched/swait.c:21 [inline]
 complete_with_flags kernel/sched/completion.c:24 [inline]
 complete+0xb0/0x200 kernel/sched/completion.c:47
 __usb_hcd_giveback_urb+0x389/0x6e0 drivers/usb/core/hcd.c:1650
 usb_giveback_urb_bh+0x28f/0x570 drivers/usb/core/hcd.c:1684
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 bh_worker+0x5a4/0x8a0 kernel/workqueue.c:3569
 workqueue_softirq_action+0x12c/0x190 kernel/workqueue.c:3596
 tasklet_action+0x14/0x70 kernel/softirq.c:810
 handle_softirqs+0x216/0x8f0 kernel/softirq.c:554
 run_ksoftirqd kernel/softirq.c:928 [inline]
 run_ksoftirqd+0x3a/0x60 kernel/softirq.c:920
 smpboot_thread_fn+0x661/0xa10 kernel/smpboot.c:164
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>


---
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