Backtrace

BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 80000003c2708067 P4D 80000003c2708067 PUD 0 
Oops: 0000 [#1] SMP PTI
CPU: 1 PID: 2430 Comm: Cache2 I/O Not tainted 5.8.18-100.fc31.x86_64 #1
Hardware name: TOSHIBA dynabook Satellite B554/M/dynabook Satellite B554/M, BIOS Version 4.80   06/23/2015
RIP: 0010:ext4_block_write_begin+0x329/0x500
Code: 34 48 8b 44 24 50 44 8b 4c 24 10 4c 8b 5c 24 08 8d 72 01 48 89 44 d4 58 44 8b 04 24 89 74 24 34 e9 af fe ff ff 48 8b 44 24 50 <48> 8b 10 83 e2 01 0f 85 9e fe ff ff 48 8b 10 83 e2 01 0f 85 92 fe
RSP: 0018:ffffaf95c1397c38 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 0000000000003000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000001000 RDI: 0000000000001000
RBP: 0000000000002000 R08: 0000000000000000 R09: 0000000000001000
R10: 0000000000000000 R11: ffff9977e64be3a8 R12: 0000000000000019
R13: ffffd65409029840 R14: 00000000ffffe000 R15: 0000000000001000
FS:  00007fea46663700(0000) GS:ffff99791f240000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000003fbdfa003 CR4: 00000000001606e0
Call Trace:
 ? jbd2__journal_start+0xf7/0x1f0
 ? ext4_da_reserve_space+0x110/0x110
 ext4_da_write_begin+0x1bc/0x480
 generic_perform_write+0xaf/0x190
 ext4_buffered_write_iter+0x8b/0x130
 ext4_file_write_iter+0x59/0x6e0
 ? lru_cache_add+0xa9/0x110
 ? handle_mm_fault+0x10ba/0x1790
 new_sync_write+0x107/0x190
 vfs_write+0x1c3/0x1f0
 ksys_write+0x4f/0xc0
 do_syscall_64+0x4d/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fea663a17df
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 19 fd ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 2d 44 89 c7 48 89 44 24 08 e8 4c fd ff ff 48
RSP: 002b:00007fea46662bd0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000003793 RCX: 00007fea663a17df
RDX: 0000000000003793 RSI: 00007fe9f8bc4000 RDI: 0000000000000124
RBP: 0000000000003793 R08: 0000000000000000 R09: 0000000000019586
R10: 0000000000019586 R11: 0000000000000293 R12: 00007fe9f8bc4000
R13: 00007fea06af59a0 R14: 00007fe9f8bc4000 R15: 0000000000003793
Modules linked in: uinput xt_CHECKSUM xt_MASQUERADE ebtable_filter ebtables tun bridge stp llc nf_nat_tftp nf_conntrack_netbios_ns nf_conntrack_broadcast nf_conntrack_tftp xt_CT ip6t_REJECT nf_reject_ipv6 ip6t_rpfilter ipt_REJECT nf_reject_ipv4 xt_conntrack ip6table_nat ip6table_mangle ip6table_raw ip6table_security iptable_nat nf_nat iptable_mangle iptable_raw iptable_security nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nfnetlink ip6table_filter ip6_tables iptable_filter sunrpc ath9k ath9k_common ath9k_hw mac80211 pn544_mei snd_hda_codec_hdmi snd_hda_codec_realtek ath mei_phy snd_hda_codec_generic ledtrig_audio pn544 cfg80211 snd_hda_intel snd_intel_dspcfg hci snd_hda_codec nfc intel_rapl_msr intel_rapl_common x86_pkg_temp_thermal intel_powerclamp coretemp rapl intel_cstate pcspkr snd_hda_core iTCO_wdt libarc4 intel_pmc_bxt iTCO_vendor_support mei_hdcp snd_hwdep intel_uncore snd_seq joydev snd_seq_device mei_me snd_pcm toshiba_acpi wmi_bmof sparse_keymap snd_timer snd
 industrialio mei lpc_ich toshiba_bluetooth rfkill soundcore tpm_infineon toshiba_haps ip_tables i915 rtsx_pci_sdmmc mmc_core i2c_algo_bit drm_kms_helper cec crct10dif_pclmul drm crc32_pclmul crc32c_intel e1000e ghash_clmulni_intel serio_raw rtsx_pci yenta_socket wmi video fuse
CR2: 0000000000000000