Backtrace

BUG: kernel NULL pointer dereference, address: 0000000000000010
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 800000008f1e1067 P4D 800000008f1e1067 PUD 8bab067 PMD 0 
Oops: 0000 [#1] SMP PTI
CPU: 0 PID: 283655 Comm: test Tainted: G           OE     5.11.12-300.fc34.x86_64 #1
Hardware name:  /DH67BL, BIOS BLH6710H.86A.0156.2012.0615.1908 06/15/2012
RIP: 0010:btcomt_uart_startup.cold+0xa0/0x1e0 [btcomt]
Code: ea c0 41 bc ea ff ff ff e8 f0 31 cd c1 e9 ea 18 ff ff 4c 89 ea 48 c7 c6 70 31 ea c0 48 c7 c7 40 6f ea c0 e8 d5 31 cd c1 eb bb <44> 8b 40 20 48 8d 88 68 01 00 00 48 c7 c6 70 31 ea c0 48 c7 c7 c0
RSP: 0018:ffff9e2c81adbbb0 EFLAGS: 00010286
RAX: fffffffffffffff0 RBX: ffffffffc0eb3720 RCX: 0000000000000000
RDX: fffffffffffffff0 RSI: 0000000000000000 RDI: ffff92d445eb40c4
RBP: ffffffffc0eb3728 R08: 0000000000000000 R09: ffff9e2c81adb9e8
R10: ffff9e2c81adb9e0 R11: ffffffff83b44f08 R12: ffffffffc0ebbdc8
R13: ffffffffc0ebbdc3 R14: ffff92d3a47fb000 R15: ffff92d3471a8d80
FS:  00007f9a6a637580(0000) GS:ffff92d45b200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 000000009be98001 CR4: 00000000001706f0
Call Trace:
 uart_port_startup+0x11d/0x230
 uart_port_activate+0x5d/0x80
 tty_port_open+0x89/0xe0
 ? tty_init_dev.part.0+0xe0/0x220
 uart_open+0x1a/0x30
 tty_open+0x168/0x670
 chrdev_open+0xe3/0x220
 ? cdev_device_add+0x90/0x90
 do_dentry_open+0x14b/0x360
 path_openat+0x9ff/0xf20
 ? do_user_addr_fault+0x1b3/0x480
 do_filp_open+0x7e/0x110
 ? 0xffffffff82000000
 ? strncpy_from_user+0xdb/0x190
 do_sys_openat2+0x7a/0x130
 __x64_sys_openat+0x45/0x70
 do_syscall_64+0x33/0x40
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f9a6a55803b
Code: 25 00 00 41 00 3d 00 00 41 00 74 4b 64 8b 04 25 18 00 00 00 85 c0 75 67 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 91 00 00 00 48 8b 54 24 28 64 48 2b 14 25
RSP: 002b:00007fff6de77200 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000401540 RCX: 00007f9a6a55803b
RDX: 0000000000000902 RSI: 000000000040206e RDI: 00000000ffffff9c
RBP: 000000000040206e R08: 0000000000000000 R09: 00007f9a6a6587b0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000902
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Modules linked in: btcomt(OE) snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio snd_seq_dummy snd_hrtimer xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 ip6table_mangle ip6table_nat ip6table_filter ip6_tables iptable_mangle iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter bridge stp llc rfkill sunrpc snd_hda_intel snd_intel_dspcfg soundwire_intel soundwire_generic_allocation snd_soc_core snd_compress snd_pcm_dmaengine intel_rapl_msr soundwire_cadence intel_rapl_common iTCO_wdt snd_hda_codec snd_hda_core ac97_bus snd_hwdep mei_hdcp snd_seq mei_me at24 intel_pmc_bxt snd_seq_device snd_pcm x86_pkg_temp_thermal intel_powerclamp snd_timer coretemp snd ftdi_sio kvm_intel iTCO_vendor_support kvm gpio_ich irqbypass i2c_i801 mei lpc_ich i2c_smbus pcspkr soundcore rapl intel_cstate intel_uncore zram ip_tables i915 video i2c_algo_bit crct10dif_pclmul crc32_pclmul drm_kms_helper crc32c_intel cec drm
 ghash_clmulni_intel e1000e serio_raw fuse [last unloaded: btcomt]
CR2: 0000000000000010