Kernel panic in the sisevt_nfsd3_proc_read() function of the sisevt module

Issue

• Kernel panic in the sisevt_nfsd3_proc_read() function of the third-party sisevt kernel module:

[   24.241031] BUG: unable to handle kernel NULL pointer dereference at 0000000000000090
[   24.241059] PGD 11194b067 P4D 11194b067 PUD 11194c067 PMD 0 
[   24.241078] Oops: 0000 [#1] SMP NOPTI
[   24.241090] CPU: 0 PID: 2524 Comm: nfsd Kdump: loaded Tainted: POE ---------- 4.18.0-553.22.1.el8_10.x86_64 #1
[   24.241115] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020
[   24.241137] RIP: 0010:sisevt_nfsd3_proc_read+0x97/0x140 [sisevt]
[   24.241162] Code: 5e 25 90 c0 bf 20 00 00 00 e8 35 8e 00 00 48 8b 05 3e 02 01 00 48 85 c0 0f 84 a1 00 00 00 48 89 df e8 ad 2d 93 c7 85 c0 75 48 <4c> 8b 85 90 00 00 00 4d 85 c0 74 3c 48 8b 95 98 00 00 00 48 85 d2
[   24.241199] RSP: 0018:ffffbffb42f3be48 EFLAGS: 00010246
[   24.241213] RAX: 0000000000000000 RBX: ffff9e5a94534000 RCX: 0000000000000000
[   24.241229] RDX: 0000000006400000 RSI: 0000000000000046 RDI: 0000000000000202
[   24.241245] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffffff8967b6c8
[   24.241261] R10: ffff9e5a8eec0600 R11: 0000000000000000 R12: ffff9e5ac49a6014
[   24.241278] R13: ffff9e5a945341e8 R14: ffff9e5a9213a500 R15: ffffffffc085c9f0
[   24.241295] FS:  0000000000000000(0000) GS:ffff9e5dafc00000(0000) knlGS:0000000000000000
[   24.241314] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   24.241328] CR2: 0000000000000090 CR3: 0000000112008000 CR4: 0000000000350ef0
[   24.241363] Call Trace:
[   24.241375]  ? __die_body+0x1a/0x60
[   24.241389]  ? no_context+0x1ba/0x3f0
[   24.241403]  ? nfsd_finish_read+0x188/0x1a0 [nfsd]
[   24.241428]  ? __bad_area_nosemaphore+0x157/0x180
[   24.241442]  ? do_page_fault+0x37/0x12d
[   24.241454]  ? page_fault+0x1e/0x30
[   24.241469]  ? sisevt_nfsd3_proc_read+0x97/0x140 [sisevt]
[   24.241487]  ? sisevt_nfsd3_proc_read+0x93/0x140 [sisevt]
[   24.241503]  ? nfsd_dispatch+0x15e/0x290 [nfsd]
[   24.241526]  ? svc_process_common+0x360/0x5c0 [sunrpc]
[   24.241558]  ? srso_return_thunk+0x5/0x5f
[   24.241572]  ? svc_sock_secure_port+0x12/0x40 [sunrpc]
[   24.241600]  ? nfsd_svc+0x320/0x320 [nfsd]
[   24.241621]  ? nfsd_shutdown_threads+0x80/0x80 [nfsd]
[   24.241644]  ? svc_process+0xb7/0xf0 [sunrpc]
[   24.241670]  ? nfsd+0xe3/0x140 [nfsd]
[   24.241690]  ? kthread+0x134/0x150
[   24.241702]  ? set_kthread_struct+0x50/0x50
[   24.241715]  ? ret_from_fork+0x35/0x40