INFO: task syz.1.7491:29365 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.7491      state:D stack:28048 pid:29365 tgid:29364 ppid:26905  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x1259/0x6980 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0xdd/0x2c0 kernel/sched/core.c:7376
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0xccf/0x1c20 kernel/locking/mutex.c:821
 nfsd_nl_unlock_filesystem_doit+0x203/0x410 fs/nfsd/nfsctl.c:2677
 genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
 genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2579
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1338 [inline]
 netlink_unicast+0x65f/0x950 net/netlink/af_netlink.c:1364
 netlink_sendmsg+0xa02/0x1020 net/netlink/af_netlink.c:1923
 sock_sendmsg_nosec net/socket.c:800 [inline]
 __sock_sendmsg net/socket.c:815 [inline]
 ____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2713
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2767
 __sys_sendmsg+0x160/0x210 net/socket.c:2799
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4ebcd9f559
RSP: 002b:00007f4ebdc11028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f4ebd025fa0 RCX: 00007f4ebcd9f559
RDX: 0000000004000080 RSI: 00002000000005c0 RDI: 0000000000000003
RBP: 00007f4ebce36b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4ebd026038 R14: 00007f4ebd025fa0 R15: 00007ffdae816be8
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/32: 1, last CPU#1:
 #0: ffffffff8fdec660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8fdec660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8fdec660 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6871
locks held by kworker/u8:3/50: 5, last CPU#0:
 #0: ffff88802822c940 ((wq_completion)krds_cp_wq#3/0){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
 #1: ffffc90000ba7d08 ((work_completion)(&(&cp->cp_conn_w)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
 #2: ffff88806baa6180 (&tc->t_conn_path_lock){+.+.}-{4:4}, at: rds_tcp_conn_path_connect+0x1da/0xaa0 net/rds/tcp_connect.c:118
 #3: ffffffff8fffd758 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline]
 #3: ffffffff8fffd758 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:305 [inline]
 #3: ffffffff8fffd758 (remove_cache_srcu){.+.+}-{0:0}, at: kasan_quarantine_reduce+0x8a/0x1f0 mm/kasan/quarantine.c:259
 #4: ffffffff8fdec660 (rcu_read_lock){....}-{1:3}, at: spin_trylock include/linux/spinlock.h:359 [inline]
 #4: ffffffff8fdec660 (rcu_read_lock){....}-{1:3}, at: __free_frozen_pages+0x57e/0x10f0 mm/page_alloc.c:2986
locks held by getty/5352: 2, on CPU#0:
 #0: ffff8880358220a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032432e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1540 drivers/tty/n_tty.c:2211
locks held by syz.8.6796/26679: 2, on CPU#0:
 #0: ffffffff91d86cc8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff90289900 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x1a3/0x1dc0 fs/nfsd/nfsctl.c:2057
locks held by syz.1.7491/29365: 2, on CPU#0:
 #0: ffffffff91d86cc8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff90289900 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_unlock_filesystem_doit+0x203/0x410 fs/nfsd/nfsctl.c:2677

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123
 nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:66
 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xcb6/0x1030 kernel/hung_task.c:561
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: d7 95 02 e9 93 54 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 13 58 16 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8fa07cf0 EFLAGS: 00000246
RAX: 0000000003c3e821 RBX: ffffffff8fa91580 RCX: ffffffff8bd562f5
RDX: 0000000000000001 RSI: ffffffff8e3e59fb RDI: ffffffff8c625e80
RBP: fffffbfff1f522b0 R08: 0000000000000001 R09: ffffed10170467bd
R10: ffff8880b8233deb R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffffffff1f40fa2 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888122940000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555962d57168 CR3: 000000000fb96000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
 default_idle+0x9/0x10 arch/x86/kernel/process.c:768
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x3ae/0x5b0 kernel/sched/idle.c:355
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454
 rest_init+0x2d3/0x2e0 init/main.c:732
 start_kernel+0x48e/0x490 init/main.c:1190
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x158
 </TASK>