INFO: task syz.2.3122:15269 blocked  for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.3122      state:D stack:25160 pid:15269 tgid:15267 ppid:5810   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1585/0x5260
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7fe/0x1300
 nfsd_nl_threads_get_doit+0x1c0/0x790
 genl_family_rcv_msg_doit+0x22a/0x330
 genl_rcv_msg+0x61c/0x7a0
 netlink_rcv_skb+0x232/0x4b0
 genl_rcv+0x28/0x40
 netlink_unicast+0x80f/0x9b0
 netlink_sendmsg+0x813/0xb40
 sock_sendmsg_nosec+0x18f/0x1d0
 ____sys_sendmsg+0x589/0x8c0
 ___sys_sendmsg+0x2a5/0x360
 __x64_sys_sendmsg+0x1bd/0x2a0
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f761419acb9
RSP: 002b:00007f761504d028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f7614415fa0 RCX: 00007f761419acb9
RDX: 0000000020044000 RSI: 0000200000000140 RDI: 0000000000000007
RBP: 00007f7614208bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7614416038 R14: 00007f7614415fa0 R15: 00007ffe3f9ad898
 </TASK>
INFO: task syz.1.3137:15314 blocked  for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.3137      state:D stack:27048 pid:15314 tgid:15313 ppid:5805   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1585/0x5260
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7fe/0x1300
 nfsd_nl_threads_get_doit+0x1c0/0x790
 genl_family_rcv_msg_doit+0x22a/0x330
 genl_rcv_msg+0x61c/0x7a0
 netlink_rcv_skb+0x232/0x4b0
 genl_rcv+0x28/0x40
 netlink_unicast+0x80f/0x9b0
 netlink_sendmsg+0x813/0xb40
 sock_sendmsg_nosec+0x18f/0x1d0
 ____sys_sendmsg+0x589/0x8c0
 ___sys_sendmsg+0x2a5/0x360
 __x64_sys_sendmsg+0x1bd/0x2a0
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2ff4f9acb9
RSP: 002b:00007f2ff5dd1028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f2ff5215fa0 RCX: 00007f2ff4f9acb9
RDX: 0000000020044000 RSI: 0000200000000140 RDI: 0000000000000003
RBP: 00007f2ff5008bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2ff5216038 R14: 00007f2ff5215fa0 R15: 00007fff5ff7ade8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e5602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5632:
 #0: ffff88811012e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc90002a502f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
2 locks held by syz.0.668/8061:
 #0: ffffffff8fa33e50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e8838e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x16c0
2 locks held by syz.2.3122/15269:
 #0: ffffffff8fa33e50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e8838e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c0/0x790
2 locks held by syz.1.3137/15314:
 #0: ffffffff8fa33e50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e8838e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c0/0x790
2 locks held by syz.4.3807/17436:
 #0: ffffffff8fa33e50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e8838e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_set_doit+0xcd/0x7a0
2 locks held by syz.3.3980/17929:
 #0: ffffffff8fa33e50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e8838e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x16c0
3 locks held by syz.5.5601/22831:
 #0: ffffffff8fa33e50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffff888115d266f0 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0
 #2: ffffffff8e8838e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xdc/0x1410
4 locks held by syz.8.6117/24377:
2 locks held by syz.6.6121/24384:
2 locks held by syz.7.6120/24387:
2 locks held by syz.7.6120/24388:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0x103d/0x1090
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 24387 Comm: syz.7.6120 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:lock_is_held_type+0x4d/0x150
Code: c9 f0 68 07 85 c0 0f 85 d5 00 00 00 65 4c 8b 2d 11 ab 68 07 41 83 bd 14 0b 00 00 00 0f 85 bf 00 00 00 89 f5 49 89 fe 9c 41 5c <fa> 48 c7 c7 e9 f0 d0 8d e8 a6 18 00 00 65 ff 05 8f f0 68 07 41 83
RSP: 0018:ffffc9000a6be988 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 0000000000000000
RDX: ffff888174bf3a00 RSI: 00000000ffffffff RDI: ffff8881bf493440
RBP: 00000000ffffffff R08: ffffc9000a6bec00 R09: ffffc9000a6bedb0
R10: dffffc0000000000 R11: ffffed1037e9267c R12: 0000000000000246
R13: ffff888174bf3a00 R14: ffff8881bf493440 R15: 0000000000000001
FS:  00007f33c6a2b6c0(0000) GS:ffff8882a969b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f33c5dde2f8 CR3: 000000016fa68000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 find_vma+0xba/0x160
 __get_user_pages+0x3ba/0x29d0
 get_dump_page+0x1b5/0x410
 dump_user_range+0x1e4/0xc70
 elf_core_dump+0x34c2/0x3ad0
 coredump_write+0x11de/0x1980
 vfs_coredump+0x36a9/0x4280
 get_signal+0x1107/0x1330
 arch_do_signal_or_restart+0xbc/0x830
 irqentry_exit+0x176/0x620
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7f33c5b9acc1
Code: 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 48 3d 01 f0 ff ff 73 01 <c3> 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f33c5e16180 RCX: 00007f33c5b9acb9
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007f33c5c08bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f33c5e16218 R14: 00007f33c5e16180 R15: 00007ffc401abbd8
 </TASK>
