Backtrace

BUG: unable to handle page fault for address: ffff88c940055820
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD e801067 P4D e801067 PUD 0 
Oops: 0000 [#1] SMP PTI
CPU: 1 PID: 3857 Comm: BgFileSaver Not tainted 5.6.6-300.fc32.x86_64 #1
Hardware name: Sony Corporation VPCEA40EL/VAIO, BIOS R1140Y8 10/06/2010
RIP: 0010:kmem_cache_alloc+0x73/0x220
Code: a7 01 00 00 4d 8b 06 65 49 8b 50 08 65 4c 03 05 5b b2 d3 77 4d 8b 20 4d 85 e4 0f 84 93 01 00 00 41 8b 46 20 49 8b 3e 4c 01 e0 <48> 8b 18 48 89 c1 49 33 9e 70 01 00 00 48 0f c9 48 31 cb 40 f6 c7
RSP: 0018:ffffaf51c156fc18 EFLAGS: 00010282
RAX: ffff88c940055820 RBX: 0000000000400000 RCX: ffff88e9dd6c7000
RDX: 0000000000002e24 RSI: 0000000000408d40 RDI: 00004667ab815690
RBP: 0000000000408d40 R08: ffffcf51bf655690 R09: ffff88e9d8a33a00
R10: 000000000021c000 R11: ffff88ea10313348 R12: ffff88c940055820
R13: ffffffff88351b7c R14: ffff88e9eae424c0 R15: ffff88ea12c22d80
FS:  00007f9ea4cff700(0000) GS:ffff88ea13e40000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff88c940055820 CR3: 00000001e4e60002 CR4: 00000000000206e0
Call Trace:
 alloc_page_buffers+0xbc/0x1b0
 create_empty_buffers+0x19/0x120
 ext4_block_write_begin+0x3e3/0x4f0
 ? jbd2__journal_start+0xf7/0x1f0
 ? ext4_da_reserve_space+0x110/0x110
 ? ext4_da_write_begin+0x193/0x4b0
 ? __ext4_journal_start_sb+0x74/0x120
 ext4_da_write_begin+0xff/0x4b0
 generic_perform_write+0xaf/0x190
 ext4_buffered_write_iter+0x9f/0x150
 new_sync_write+0x117/0x1a0
 vfs_write+0xb6/0x1a0
 ksys_write+0x4f/0xc0
 do_syscall_64+0x5b/0xf0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f9ece85d90f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 29 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 31 44 89 c7 48 89 44 24 08 e8 5c fd ff ff 48
RSP: 002b:00007f9ea4cfe790 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f9e9f8fee60 RCX: 00007f9ece85d90f
RDX: 0000000000008000 RSI: 00007f9e9ddf7000 RDI: 0000000000000055
RBP: 0000000000008000 R08: 0000000000000000 R09: 00007f9e9ddfe030
R10: 00000000ce864701 R11: 0000000000000293 R12: 00007f9e9ddf7000
R13: 00007f9e9c0dc160 R14: 0000000000000000 R15: 0000000000008000
Modules linked in: uinput rfcomm nft_objref nf_conntrack_netbios_ns nf_conntrack_broadcast nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nf_tables_set nft_chain_nat ip6table_nat ip6table_mangle ip6table_raw ip6table_security iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c ccm iptable_mangle iptable_raw iptable_security ip_set nf_tables nfnetlink ip6table_filter ip6_tables iptable_filter bnep sunrpc intel_powerclamp coretemp kvm_intel kvm snd_hda_codec_hdmi uvcvideo snd_hda_codec_realtek videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev snd_hda_codec_generic mc ath9k ledtrig_audio ath9k_common ath9k_hw mac80211 ath cfg80211 libarc4 btusb btrtl btbcm btintel snd_hda_intel snd_intel_dspcfg bluetooth irqbypass snd_hda_codec ecdh_generic ecc iTCO_wdt iTCO_vendor_support snd_hda_core snd_hwdep snd_seq snd_seq_device intel_cstate pcspkr intel_uncore joydev snd_pcm
 snd_timer mei_me snd soundcore mei sony_laptop intel_ips rfkill i2c_i801 lpc_ich acpi_cpufreq ip_tables i915 i2c_algo_bit cec drm_kms_helper sdhci_pci crc32c_intel drm cqhci sdhci serio_raw mmc_core sky2 video fuse
CR2: ffff88c940055820