Re: [syzbot] [nfs?] INFO: task hung in nfsd_nl_listener_set_doit

[syzbot <syzbot+d1e76d963f757db40f91@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in nfsd_create_serv

------------[ cut here ]------------
WARNING: CPU: 0 PID: 6124 at fs/nfsd/nfssvc.c:656 nfsd_create_serv+0x631/0x760 fs/nfsd/nfssvc.c:656
Modules linked in:
CPU: 0 UID: 0 PID: 6124 Comm: syz.3.18 Not tainted 6.11.0-rc5-syzkaller-00151-gfe1910f9337b-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:nfsd_create_serv+0x631/0x760 fs/nfsd/nfssvc.c:656
Code: 43 0f b6 44 25 00 84 c0 0f 85 f5 00 00 00 48 8b 44 24 18 ff 00 48 8b 7c 24 30 e8 ba 60 15 09 e9 cd fa ff ff e8 c0 53 e5 fe 90 <0f> 0b 90 e9 91 fa ff ff 48 c7 c1 00 88 47 9a 80 e1 07 80 c1 03 38
RSP: 0018:ffffc90003aaf000 EFLAGS: 00010293
RAX: ffffffff82ae3870 RBX: ffff88801276bb80 RCX: ffff888055cf9e00
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ec0b5c0
RBP: ffffc90003aaf190 R08: ffffffff8ec0b5c7 R09: 1ffffffff1d816b8
R10: dffffc0000000000 R11: fffffbfff1d816b9 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888032c74000 R15: 1ffff92000755e08
FS:  00007fb26fd8a6c0(0000) GS:ffff8880b8800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000100 CR3: 00000000318c8000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 nfsd_nl_listener_set_doit+0x13f/0x19f0 fs/nfsd/nfsctl.c:1958
 genl_family_rcv_msg_doit net/netlink/genetlink.c:1116 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:1196 [inline]
 genl_rcv_msg+0xb4e/0xef0 net/netlink/genetlink.c:1211
 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2550
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1220
 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
 netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357
 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:745
 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597
 ___sys_sendmsg net/socket.c:2651 [inline]
 __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2680
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb26ef79eb9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb26fd8a038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fb26f115f80 RCX: 00007fb26ef79eb9
RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000003
RBP: 00007fb26efe793e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb26f115f80 R15: 00007fffd4289438
 </TASK>


Tested on:

commit:         fe1910f9 tcp_bpf: fix return value of tcp_bpf_sendmsg()
git tree:       net
console output: https://syzkaller.appspot.com/x/log.txt?x=1548dc67980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=996585887acdadb3
dashboard link: https://syzkaller.appspot.com/bug?extid=d1e76d963f757db40f91
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1517ab39980000