After upgrading OpenWRT from 3.14.28 to 3.14.30, the system started oopsing.
This problem does not happen with the ocf talitos driver.

[ 92.259289] Unable to handle kernel paging request for data at address 0x00000000
[ 92.266876] Faulting instruction address: 0xf32bb1cc
[ 92.271926] Oops: Kernel access of bad area, sig: 11 [#1]
[ 92.277323] SMP NR_CPUS=2 P1020 RDB
[ 92.280811] Modules linked in: iptable_nat ath9k nf_nat_ipv4 nf_conntrack_ipv4 ipt_MASQUERADE ebtable_nat ebtable_filter ebtable_broute carl9170 ath9k_htc ath9k_common 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 nf_nat_irc nf_nat_ftp nf_nat nf_defrag_ipv4 nf_conntrack_rtcache nf_conntrack_irc nf_conntrack_ftp nf_conntrack macvlan mac80211 lzo_decompress lzo_compress libcrc32c iptable_raw iptable_mangle iptable_filter ipt_REJECT ip_tables ebtables ebt_vlan ebt_ulog ebt_stp ebt_snat ebt_redirect ebt_pkttype ebt_nflog ebt_mark_m ebt_mark ebt_log ebt_limit ebt_ip6 ebt_ip ebt_dnat ebt_arpreply ebt_arp ebt_among ebt_802_3 crc8 crc7 crc_itu_t crc_ccitt ath9k_hw ath sch_teql sch_tbf sch_sfq sch_red sch_prio sch_htb
[ 92.351592] sch_gred sch_dsmark sch_codel em_text em_nbyte em_meta em_cmp cls_basic act_police act_ipt act_skbedit act_mirred em_u32 cls_u32 cls_tcindex cls_flow cls_route cls_fw sch_hfsc sch_ingress i2c_dev ledtrig_morse ledtrig_heartbeat ledtrig_gpio booke_wdt xt_set x_tables ip_set_list_set ip_set_hash_netport ip_set_hash_netiface ip_set_hash_net ip_set_hash_ipportnet ip_set_hash_ipportip ip_set_hash_ipport ip_set_hash_ip ip_set_bitmap_port ip_set_bitmap_ipmac ip_set_bitmap_ip ip_set msdos vfat fat nls_utf8 ipv6 bridge stp chainiv eseqiv psnap p8022 llc xts crypto_wq algif_skcipher algif_hash af_alg krng rng cryptosoft cryptodev ocf crypto_null michael_mic md5 md4 talitos hmac gf128mul ecb des_generic deflate zlib_deflate cbc authenc aead arc4 crypto_blkcipher cfg80211 compat i2c_mpc mmc_block
[ 92.421087] gpio_keys_polled usb_storage tun mmc_core input_polldev leds_gpio sd_mod scsi_mod button_hotplug crc32c
[ 92.430348] CPU: 1 PID: 5521 Comm: twistd Not tainted 3.14.30 #2
[ 92.436350] task: efaf0000 ti: c4d3a000 task.ti: c4d3a000
[ 92.441743] [stack] NIP: f32bb1cc LR: f32bc550 CTR: c00ca964
[ 92.447396] [stack] REGS: c4d3bc20 TRAP: 0300 Not tainted (3.14.30)
[ 92.453914] [stack] MSR: 00029000 <CE,EE,ME> CR: 84022044 XER: 00000000
[stack] DEAR: 00000000 ESR: 00000000
[stack] GPR00: f32bc550 c4d3bcd0 efaf0000 ee4dce10 00000000 00000001 00000001 00000000
[stack] GPR08: c4d3a000 00000000 00000001 c56a4f60 84022042 100187c4 00000000 00000001
[stack] GPR16: b7b63754 10891f70 00000083 00000000 10bcd9ac b7b5b79c 00000001 10e98904
[stack] GPR24: 10df5c28 c0474ccc 00000001 00000000 ee4dce10 00000001 00000000 00000000
[ 92.495219] [stack] NIP [f32bb1cc] talitos_submit+0x1b84/0x3ffc [talitos]
[ 92.502010] [stack] LR [f32bc550] talitos_submit+0x2f08/0x3ffc [talitos]
[ 92.508702] [stack] Call Trace:
[ 92.511849] [stack] [c4d3bcd0] [b7b5b79c] 0xb7b5b79c (unreliable)
[ 92.517953] [stack] [c4d3bd00] [f32bc550] talitos_submit+0x2f08/0x3ffc [talitos]
[ 92.525354] [stack] [c4d3bd50] [f3313f40] cryptodev_hash_final+0x38/0xb74 [cryptodev]
[ 92.533189] [stack] [c4d3bd60] [f33133e8] crypto_run+0x3d0/0x454 [cryptodev]
[ 92.540243] [stack] [c4d3bd90] [f3312c0c] crypto_get_session_by_sid+0xa50/0xe5c [cryptodev]
[ 92.548597] [stack] [c4d3bec0] [c00e16d8] do_vfs_ioctl+0x66c/0x788
[ 92.554775] [stack] [c4d3bf20] [c00e184c] SyS_ioctl+0x58/0x8c
[ 92.560525] [stack] [c4d3bf40] [c000e490] ret_from_syscall+0x0/0x3c
[ 92.566807] [stack] --- Exception: c01 at 0xb78dc910
[stack] LR = 0xb792fb44
[ 92.575499] [stack] Instruction dump:
[stack] 577b003a 2f9b0000 409eff80 48000078 2f830000 419e000c 832300e0 48000008
[stack] 3b200000 7f7edb78 3be00000 48000020 <807e0000> 3bff0001 5463003a 480024d1
[ 92.593741] ---[ end trace 12d31850e8bcced9 ]---