[syzbot ci] Re: net/smc: fix clcsock and lgr/lnk races in smc_diag dump path

[syzbot ci <syzbot+cia7ddf4f17dfab266@syzkaller.appspotmail.com>]

syzbot ci has tested the following series

[v3] net/smc: fix clcsock and lgr/lnk races in smc_diag dump path
https://lore.kernel.org/all/20260807081606.3200128-1-mjambigi@linux.ibm.com
* [PATCH net v3] net/smc: fix clcsock and lgr/lnk races in smc_diag dump path

and found the following issue:
WARNING in smc_diag_dump_proto

Full report is available here:
https://ci.syzbot.org/series/ab0d12fd-741a-4a0f-9f49-e52b84e94f4a

***

WARNING in smc_diag_dump_proto

tree:      net
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net.git
base:      594d905195024b228c962627ae5ae7c17bd582a4
arch:      amd64
compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/0c4d246f-d098-4afe-b6bc-0f0ad52f55f8/config
syz repro: https://ci.syzbot.org/findings/fa5564b8-8db6-4f76-9d75-dbd796435d87/syz_repro

------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: kernel/locking/mutex.c:625 at __mutex_lock_common kernel/locking/mutex.c:625 [inline], CPU#0: syz.0.161/6326
WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x12d8/0x1550 kernel/locking/mutex.c:821, CPU#0: syz.0.161/6326
Modules linked in:
CPU: 0 UID: 0 PID: 6326 Comm: syz.0.161 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:__mutex_lock_common kernel/locking/mutex.c:625 [inline]
RIP: 0010:__mutex_lock+0x12df/0x1550 kernel/locking/mutex.c:821
Code: de 57 90 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 47 02 00 00 83 3d 45 cc 83 04 00 75 13 48 8d 3d a8 1b 87 04 48 c7 c6 40 f7 ec 8b <67> 48 0f b9 3a 90 e9 75 ee ff ff 90 0f 0b 90 e9 48 f2 ff ff 90 0f
RSP: 0018:ffffc900068c6e40 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff888170ffd940
RDX: 0000000000000000 RSI: ffffffff8becf740 RDI: ffffffff905b2db0
RBP: ffffc900068c6fd0 R08: ffffffff9057de43 R09: 1ffffffff20afbc8
R10: dffffc0000000000 R11: fffffbfff20afbc9 R12: ffff8881b1006648
R13: 0000000000000000 R14: 1ffff92000d18ddc R15: 0000000000000000
FS:  00007f4dacd826c0(0000) GS:ffff88818d945000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000000e000 CR3: 0000000171350000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 smc_diag_msg_common_fill net/smc/smc_diag.c:50 [inline]
 __smc_diag_dump net/smc/smc_diag.c:101 [inline]
 smc_diag_dump_proto+0x6d2/0x2620 net/smc/smc_diag.c:255
 smc_diag_dump+0x59/0xa0 net/smc/smc_diag.c:278
 netlink_dump+0x711/0xee0 net/netlink/af_netlink.c:2331
 __netlink_dump_start+0x589/0x7b0 net/netlink/af_netlink.c:2446
 netlink_dump_start include/linux/netlink.h:341 [inline]
 smc_diag_handler_dump+0x199/0x240 net/smc/smc_diag.c:293
 sock_diag_rcv_msg+0x4b0/0x5f0 net/core/sock_diag.c:-1
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775
 __sock_sendmsg net/socket.c:790 [inline]
 ____sys_sendmsg+0x54e/0x850 net/socket.c:2684
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738
 __sys_sendmsg net/socket.c:2770 [inline]
 __do_sys_sendmsg net/socket.c:2775 [inline]
 __se_sys_sendmsg net/socket.c:2773 [inline]
 __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4dabf9e019
Code: ff c3 66 2e 0f 1f 84 00 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
RSP: 002b:00007f4dacd82028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f4dac226090 RCX: 00007f4dabf9e019
RDX: 0000000000000600 RSI: 0000200000000540 RDI: 0000000000000003
RBP: 00007f4dac03500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4dac226128 R14: 00007f4dac226090 R15: 00007ffe0de8ec98
 </TASK>
----------------
Code disassembly (best guess):
   0:	de 57 90             	ficoms -0x70(%rdi)
   3:	48 c1 e8 03          	shr    $0x3,%rax
   7:	0f b6 04 18          	movzbl (%rax,%rbx,1),%eax
   b:	84 c0                	test   %al,%al
   d:	0f 85 47 02 00 00    	jne    0x25a
  13:	83 3d 45 cc 83 04 00 	cmpl   $0x0,0x483cc45(%rip)        # 0x483cc5f
  1a:	75 13                	jne    0x2f
  1c:	48 8d 3d a8 1b 87 04 	lea    0x4871ba8(%rip),%rdi        # 0x4871bcb
  23:	48 c7 c6 40 f7 ec 8b 	mov    $0xffffffff8becf740,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	90                   	nop
  30:	e9 75 ee ff ff       	jmp    0xffffeeaa
  35:	90                   	nop
  36:	0f 0b                	ud2
  38:	90                   	nop
  39:	e9 48 f2 ff ff       	jmp    0xfffff286
  3e:	90                   	nop
  3f:	0f                   	.byte 0xf


***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
  Tested-by: syzbot@syzkaller.appspotmail.com

---
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