OSP16.2 controller nodes crash often due to the null-deref happens in iscsi_sw_tcp_conn_get_param()

Issue

• OSP16.2 controller nodes crash often due to the null-deref happens in iscsi_sw_tcp_conn_get_param()

[108027.169542] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[108027.170080] PGD 0 P4D 0 
[108027.170257] Oops: 0000 [#1] SMP NOPTI
[108027.170505] CPU: 22 PID: 970466 Comm: iscsiadm Kdump: loaded Not tainted 4.18.0-305.40.2.el8_4.x86_64 #1
[108027.171106] Hardware name: Red Hat RHEL/RHEL-AV, BIOS 1.15.0-2.module+el8.6.0+14757+c25ee005 04/01/2014
[108027.171718] RIP: 0010:iscsi_sw_tcp_conn_get_param+0x6b/0x100 [iscsi_tcp]
[108027.172149] Code: ff ff 48 8b 4c 24 28 65 48 33 0c 25 28 00 00 00 0f 85 9a 00 00 00 48 83 c4 30 5b 5d 41 5c 41 5d c3 4c 8b 67 20 49 8b 44 24 08 <4c> 8b 68 08 49 8b 44 24 10 48 8d b8 10 01 00 00 e8 30 24 45 d5 4d
[108027.173323] RSP: 0018:ffffa417a08cbdb8 EFLAGS: 00010293
[108027.173662] RAX: 0000000000000000 RBX: 0000000000000015 RCX: ffff94ee2f40daa0
[108027.174114] RDX: ffff94dab7b4f000 RSI: 0000000000000015 RDI: ffff94d88f4e5000
[108027.174574] RBP: ffff94dab7b4f000 R08: ffff94d53b6db838 R09: ffff94d8d5046cc0
[108027.175020] R10: ffff94dab7b4f000 R11: 0000000000000001 R12: ffff94d88f4e5438
[108027.175488] R13: ffffffffc0100040 R14: ffff94dab7b4f000 R15: ffff94ee6affee00
[108027.175931] FS:  00007f521f065f80(0000) GS:ffff94f03f380000(0000) knlGS:0000000000000000
[108027.176449] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[108027.176811] CR2: 0000000000000008 CR3: 00000022a773c004 CR4: 00000000007706e0
[108027.177265] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[108027.177713] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[108027.178149] PKRU: 55555554
[108027.178325] Call Trace:
[108027.178515]  ? memcg_slab_post_alloc_hook+0x10c/0x1d0
[108027.178840]  show_conn_ep_param_ISCSI_PARAM_CONN_ADDRESS+0x77/0x90 [scsi_transport_iscsi]
[108027.179389]  dev_attr_show+0x1c/0x40
[108027.179626]  sysfs_kf_seq_show+0x9b/0x100
[108027.179904]  seq_read+0x163/0x420
[108027.180118]  vfs_read+0x91/0x140
[108027.180323]  ksys_read+0x4f/0xb0
[108027.180535]  do_syscall_64+0x5b/0x1a0
[108027.180770]  entry_SYSCALL_64_after_hwframe+0x65/0xca
[108027.181081] RIP: 0033:0x7f521da285a5
[108027.181311] Code: fe ff ff 50 48 8d 3d f2 f6 09 00 e8 f5 fd 01 00 0f 1f 44 00 00 f3 0f 1e fa 48 8d 05 f5 6f 2d 00 8b 00 85 c0 75 0f 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 53 c3 66 90 41 54 49 89 d4 55 48 89 f5 53 89
[108027.182435] RSP: 002b:00007ffff005fce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[108027.182891] RAX: ffffffffffffffda RBX: 000055f213b68a40 RCX: 00007f521da285a5
[108027.183326] RDX: 0000000000000402 RSI: 000055f213b68a40 RDI: 0000000000000003
[108027.183799] RBP: 00007f521f065e38 R08: 00007f521dcfabc0 R09: 0000000000000007
[108027.184249] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000402
[108027.184710] R13: 0000000000000003 R14: 00007f521dd19ba8 R15: 0000000000000402
[108027.185174] Modules linked in: [...]
[108027.191302] CR2: 0000000000000008

• The null-deref crash happens in "iscsiadm" task's context.