RHEL8: kernel panic at n_tty_set_termios+0x30

Issue

• Kernel panic with below logs:

[2621402.542276] BUG: unable to handle kernel NULL pointer dereference at 000000000000005d
[2621402.542280] PGD 0 P4D 0 
[2621402.542282] Oops: 0000 [#1] SMP PTI
[2621402.542285] CPU: 2 PID: 1975792 Comm: in.telnetd Kdump: loaded Tainted: G                 ---------r-  - 4.18.0-240.15.1.el8_3.x86_64 #1
[2621402.542286] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 12/12/2018
[2621402.542291] RIP: 0010:n_tty_set_termios+0x30/0x2e0
[2621402.542293] Code: 48 89 fb 48 8b 97 78 02 00 00 48 85 f6 0f 84 99 00 00 00 8b 87 1c 01 00 00 8b 4e 0c 31 c1 81 e1 02 00 01 00 0f 85 82 00 00 00 <0f> b6 4a 5d d1 e8 83 e0 01 83 e1 ef c1 e0 04 09 c8 88 42 5d 8b 8b
[2621402.542295] RSP: 0018:ffffb34013787c98 EFLAGS: 00010246
[2621402.542296] RAX: 0000000000008a33 RBX: ffff9fcdeb4b6400 RCX: 0000000000000000
[2621402.542297] RDX: 0000000000000000 RSI: ffffb34013787cac RDI: ffff9fcdeb4b6400
[2621402.542298] RBP: ffff9fcdeb4b64c0 R08: ffffb34013787cd0 R09: 0000000000000000
[2621402.542299] R10: 0000000000000000 R11: 0000000000000001 R12: ffff9fce0150bb90
[2621402.542300] R13: 00007ffe887066d0 R14: ffffb34013787d0c R15: 0000000000000000
[2621402.542301] FS:  00007f82193e4740(0000) GS:ffff9fd06fb00000(0000) knlGS:0000000000000000
[2621402.542303] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[2621402.542304] CR2: 000000000000005d CR3: 00000002abf54002 CR4: 00000000007606e0
[2621402.542338] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[2621402.542340] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[2621402.542340] PKRU: 55555554
[2621402.542341] Call Trace:
[2621402.542349]  tty_set_termios+0x1d6/0x240
[2621402.542351]  set_termios+0x148/0x210
[2621402.542353]  tty_mode_ioctl+0x4a1/0x4c0
[2621402.542358]  tty_ioctl+0x25e/0x890
[2621402.542363]  ? new_sync_write+0x124/0x170
[2621402.542366]  do_vfs_ioctl+0xa4/0x640
[2621402.542374]  ? syscall_trace_enter+0x1d3/0x2c0
[2621402.542376]  ksys_ioctl+0x60/0x90
[2621402.542379]  __x64_sys_ioctl+0x16/0x20
[2621402.542381]  do_syscall_64+0x5b/0x1a0
[2621402.542387]  entry_SYSCALL_64_after_hwframe+0x65/0xca
[2621402.542395] RIP: 0033:0x7f8218d02ea9
[2621402.542397] Code: 44 24 11 88 44 24 10 44 89 c8 89 54 24 04 49 8b 50 08 66 41 89 4a 21 48 89 54 24 08 41 0f b6 50 23 41 88 52 23 4c 89 d2 0f 05 <48> 89 c2 48 3d 00 f0 ff ff 0f 87 98 00 00 00 85 c0 75 4c 48 81 fd