[FS#137] Kernel panic with zram

[LEDE Bugs]

A new Flyspray task has been opened.  Details are below. 

User who did this - Github Issues (github-import) 

Attached to Project - LEDE Project
Summary - Kernel panic with zram 
Task Type - Bug Report
Category - Base system
Status - Unconfirmed
Assigned To - 
Operating System - All
Severity - Low
Priority - Very Low
Reported Version - Trunk
Due in Version - Undecided
Due Date - Undecided
Details - Github issue #296, reported by https://github.com/Ansuel

I have compiled my image with zram support and i have this bug related to the kernel. After that my router panic and reboot

[ 33.149266] Kernel bug detected[#1]:
[ 33.152913] CPU: 0 PID: 7 Comm: kworker/u2:1 Not tainted 4.4.19 #0
[ 33.159203] Workqueue: writeback wb_workfn (flush-254:0)
[ 33.164610] task: 87c31e30 ti: 87cbe000 task.ti: 87cbe000
[ 33.170078] $ 0 : 00000000 00000001 00000001 00000001
[ 33.175410] $ 4 : 87f7d400 87cbf990 00000000 00008000
[ 33.180743] $ 8 : 87f7d800 00080000 00000001 00000001
[ 33.186076] $12 : 00000120 8100ca20 00000000 00000100
[ 33.191409] $16 : 87929068 87cbfa88 87f7d800 00000000
[ 33.196741] $20 : 87f7d800 87f7d400 87f7d400 00000001
[ 33.202075] $24 : 00000000 8748c9a4

[ 33.207407] $28 : 87cbe000 87cbf938 00000001 874bcbfc
[ 33.212740] Hi : 00000000
[ 33.215662] Lo : 00000001
[ 33.218662] epc : 874bc1c0 ext4_set_bits+0x2980/0x3ad0 [ext4]
[ 33.224687] ra : 874bcbfc ext4_set_bits+0x33bc/0x3ad0 [ext4]
[ 33.230685] Status: 1100dc03 KERNEL EXL IE 
[ 33.234963] Cause : 00800034 (ExcCode 0d)
[ 33.239029] PrId : 0001974c (MIPS 74Kc)
[ 33.243003] Modules linked in: ath9k ath9k_common pppoe ppp_async iptable_nat ath9k_hw ath pppox ppp_generic nf_nat_ipv4 nf_conntrack_ipv6 nf_conntrack_ipv4 mac80211 ipt_REJECT ipt_MASQUERADE cfg80211 xt_time xt_tcpudp xt_state xt_nat xt_multiport xt_mark xt_mac xt_limit xt_id xt_conntrack xt_comment xt_TCPMSS xt_REDIRECT xt_LOG xt_CT usblp ums_usbat ums_sddr55 ums_sddr09 ums_karma ums_jumpshot ums_isd200 ums_freecom ums_datafab ums_cypress ums_alauda slhc nf_reject_ipv4 nf_nat_redirect nf_nat_masquerade_ipv4 nf_nat nf_log_ipv4 nf_defrag_ipv6 nf_defrag_ipv4 nf_conntrack_rtcache nf_conntrack_netlink nf_conntrack iptable_raw iptable_mangle iptable_filter ip_tables crc_ccitt compat ledtrig_usbdev xt_set ip_set_list_set ip_set_hash_netiface ip_set_hash_netport ip_set_hash_netnet ip_set_hash_net ip_set_hash_netportnet ip_set_hash_mac ip_set_hash_ipportnet ip_set_hash_ipportip ip_set_hash_ipport ip_set_hash_ipmark ip_set_hash_ip ip_set_bitmap_port ip_set_bitmap_ipmac ip_set_bitmap_ip ip_set nfnetlink ip6t_REJECT nf_reject_ipv6 nf_log_ipv6 nf_log_common ip6table_raw ip6table_mangle ip6table_filter ip6_tables x_tables usb_storage ehci_pci ehci_platform ehci_hcd sd_mod scsi_mod gpio_button_hotplug usbcore nls_base usb_common ext4 mbcache jbd2 crypto_hash crc16 zram zsmalloc lzo_decompress lzo_compress lz4_decompress lz4_compress
[ 33.362435] Process kworker/u2:1 (pid: 7, threadinfo=87cbe000, task=87c31e30, tls=00000000)
[ 33.370902] Stack : 00000000 81000000 810e9d40 874fed80 804f7b10 00000000 00000000 0000000a
[ 33.370902] 00000000 80099df8 87d8d680 87929068 87cbfa88 87cbfa78 00000000 874bcbfc
[ 33.370902] 810d8bc0 00000000 87929068 87f7d800 87cbfa78 874b8224 00000000 801228c8
[ 33.370902] 00000000 00000001 87cbf9a8 87cbf9ac 00000001 00000000 87929068 87cbfa88
[ 33.370902] 87cbfa78 00000000 87f7d800 00000000 87f7d400 00000001 00000000 874be4d4
[ 33.370902] ...
[ 33.407231] Call Trace:
[ 33.409739] [] ext4_set_bits+0x2980/0x3ad0 [ext4]
[ 33.415428] [] ext4_set_bits+0x33bc/0x3ad0 [ext4]
[ 33.421087] 
[ 33.422593] 
[ 33.422593] Code: 8e420020 0062102b 38420001  96020050 30420200 10400080 00000000 8e420080 
[ 33.432826] ---[ end trace 6f97ef034652357b ]---

Any idea about this?

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=137