Here's the stacktrace from /proc/last_kmsg.  This is clearly another knock-on problem from udev (not ueventd) handling the firmware requests.

We may want to disable /lib/udev/rules.d/50-firmware.rules on these images as a workaround.

[13793.644710] 
[13793.644710]  err: request_firmware for vidc_1080p.fw error -2
[13793.644863] <3>wfd: Failed to load video encoder firmware: 1
[13793.644985] mdp4_writeback_terminate called without stopping
[13793.645076] Unable to handle kernel NULL pointer dereference at virtual address 0000000d
[13793.645229] pgd = ebdf8000
[13793.645290] [0000000d] *pgd=aa238831, *pte=00000000, *ppte=00000000
[13793.645626] Internal error: Oops: 17 [#1] PREEMPT SMP ARM
[13793.645717] Modules linked in:
[13793.645901] CPU: 1    Not tainted  (3.4.0-1-mako #7-Ubuntu)
[13793.645992] PC is at do_sys_open+0x108/0x178
[13793.646084] LR is at path_openat+0x36c/0x388
[13793.646236] pc : <c0145954>    lr : <c0154fa4>    psr: 00000013
[13793.646236] sp : ecadbf58  ip : ecadbe78  fp : ecadbf94
[13793.646419] r10: 00000000  r9 : ecada000  r8 : c000e2a8
[13793.646511] r7 : ffffff9c  r6 : ebd2e000  r5 : 00000001  r4 : 00000003
[13793.646633] r3 : 00000000  r2 : 00000000  r1 : 00010000  r0 : 00000001
[13793.646725] Flags: nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[13793.646847] Control: 10c5787d  Table: ac7f806a  DAC: 00000015
[13793.646969] 
[13793.646969] PC: 0xc01458d4:
[13793.647121] 58d4  e3832c02 13833c06 e50b2028 150b3028 e31c0901 e1a00001 03a05000 13a05002
[13793.647854] 58f4  e31c0902 03855001 eb002f75 e3700a01 e1a06000 81a04000 8a000028 e1a01004
[13793.648403] init: Handling graphics-device-added event
[13793.648647] 
[13793.648708] 5914  e3a00000 eb006ce7 e2504000 ba000021 e1a03005 e1a00007 e1a01006 e24b2034
[13793.649441] 5934  eb003ddb e3700a01 e1a05000 9a000003 e1a00004 e1a04005 ebfff9e3 ea000015
[13793.650112] 5954  e590100c e2807008 e1a00007 e591a020 e1da80b0 e2088a0f e3580901 03a08181
[13793.650814] 5974  13a08020 e1a02008 eb00eb1c e3a03000 e1a01008 e58d3000 e58d3004 e1a0000a
[13793.651547] 5994  e1a02007 e3a03001 eb00ea32 e1a00004 e1a01005 ebfffc03 e1a00006 eb002f51
[13793.652279] 59b4  e1a00004 e24bd024 e89dadf0 c0aeaadb e1a0c00d e92dd800 e24cb004 e52de004
[13793.652951] 
[13793.652951] LR: 0xc0154f24:
[13793.653164] 4f24  e1a03008 ebfffce3 e1a05000 e51b0030 e3760a01 e5903020 8a000006 e5933018
[13793.653866] 4f44  e5933014 e3530000 0a000002 e1a01004 e1a02006 e12fff33 e24b0034 ebffee8b
[13793.654568] 4f64  e3550000 0affff66 e5943014 e3530000 0a000004 e5943020 e3130a02 1a000001
[13793.655301] 4f84  e2840014 ebffee81 e51b0040 e3500000 0a000000 ebffcd15 e1a00004 ebffff13
[13793.656033] 4fa4  ea000002 e1a05000 eaffffee e3e05016 e1a00005
[13793.656430] init: Handling firmware-device-added event
[13793.656644]  e24bd028 e89daff0 e1a0c00d
[13793.656888] 4fc4  e92dd800 e24cb004 e52de004 e8bd4000 e1a02000 e1a03001 e3e00063 e1a01002
[13793.657590] 4fe4  e3a02010 ebfff931 e89da800 e1a0c00d e92dd9f0 e24cb004 e24dd064 e52de004
[13793.658231] 5004  e8bd4000 e1a06002 e1a08000 e1a00001 e1a01002 e59b2004 e1a07003 ebfff155
[13793.658963] 
[13793.658994] SP: 0xecadbed8:
[13793.659116] bed8  eefdb490 ef368f80 5c1a0fc1 c0145954 00000013 ffffffff ecadbf44 c000e2a8
[13793.659848] bef8  ecada000 00000000 ecadbf94 ecadbf10 c08ba618 c0008364 00000001 00010000
[13793.660581] bf18  00000000 00000000 00000003 00000001 ebd2e000 ffffff9c c000e2a8 ecada000
[13793.661252] bf38  00000000 ecadbf94 ecadbe78 ecadbf58 c0154fa4 c0145954 00000013 ffffffff
[13793.661924] bf58  c0096d18 c02d2df4 00020000 ecad0000 00000024 00000100 bee969c2 00000000
[13793.662656] bf78  a18ee500 00000005 c000e2a8 00000000 ecadbfa4 ecadbf98 c01459f4 c0145858
[13793.663389] bf98  00000000 ecadbfa8 c000e020
[13793.663633] init: Handling firmware-device-removed event
[13793.663847]  c01459d0 bee969c2 00000000 bee969c2 00020000
[13793.664243] bfb8  00000000 00000000 bee969c2 00000000 a18ee500 00000005 00000000 00000000
[13793.664976] 
[13793.664976] IP: 0xecadbdf8:
[13793.665128] bdf8  ecadbe14 ecadbe08 c0162c6c c0162adc ecadbe2c ecadbe18 c01509bc c0162c44
[13793.665861] be18  00000000 ecadbed8 ecadbe74 ecadbe30 c0154a20 c0145954 ecadbf10 00000017
[13793.666563] be38  0000000d c0d92a0c ecada000 00000007 ecadbf0c ecadbe58 c00084c8 c08bc0b0
[13793.667265] be58  ecadbf60 ebd2e000 ecada000 c0154fa4 ecadbecc ecadbe78 c0154fa4 c0154c00
[13793.667997] be78  ecadbe8c ecaba3b8 ee6657a8 00000000 00000000 00000000 eefdb490 ef368f80
[13793.668699] be98  ecadbeb0 c0162b34 ecadbecc ecadbf60 00000001 ebd2e000 ffffff9c c000e2a8
[13793.669432] beb8  ecada000 00000000 ecadbf54 ecadbed0 c01550e4 c0154c44 00000041 00000017
[13793.670103] bed8  eefdb490 ef368f80 5c1a0fc1 c0145954 00000013 ffffffff ecadbf44 c000e2a8
[13793.670836] 
[13793.670836] FP: 0xecadbf14:
[13793.670958] bf14  00010000 00000000 00000000 00000003 00000001 ebd2e000 ffffff9c c000e2a8
[13793.671690] bf34  ecada000 00000000 ecadbf94 ecadbe78 ecadbf58 c0154fa4 c0145954 00000013
[13793.672423] bf54  ffffffff c0096d18 c02d2df4 00020000 ecad0000 00000024 00000100 bee969c2
[13793.673155] bf74  00000000 a18ee500 00000005 c000e2a8 00000000 ecadbfa4 ecadbf98 c01459f4
[13793.673827] bf94  c0145858 00000000 ecadbfa8 c000e020 c01459d0 bee969c2 00000000 bee969c2
[13793.674529] bfb4  00020000 00000000 00000000 bee969c2 00000000 a18ee500 00000005 00000000
[13793.675261] bfd4  00000000 40078000 00000000 00000005 bee966b8 401ef6fd 40180706 60000030
[13793.675902] bff4  bee969c2 00000000 00000000 ecadf800 ecadc01c ecadc11c 000000ce 00000100
[13793.676573] 
[13793.676573] R6: 0xebd2df80:
[13793.676757] df80  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[13793.677428] dfa0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[13793.678161] dfc0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[13793.678893] dfe0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[13793.679564] e000  7665642f 6469762f 39336f65 672d7800 6165756e 66686962 62696c2f 6f732e63
[13793.680205] e020  6400362e 746f6e2d 756f662d 3000646e 32353031 0a426b20 66667542 3a737265
[13793.680938] e040  20202020 20202020 33202020 30343139 0a426b20 68636143 203a6465 20202020
[13793.681670] e060  20202020 34332020 32393935 0a426b20 70617753 68636143 203a6465 20202020
[13793.682342] 
[13793.682342] R8: 0xc000e228:
[13793.682525] e228  3798f107 e28d1008 e3a08000 e357080f e2270000 2a001190 ea021374 e1a02007
[13793.683196] e248  e28d1008 e3a00000 eb0009b4 e28fe014 e1a07000 e28d1008 e3570f5f 3891000f
[13793.683868] e268  3798f107 eaffffef e5ad0008 e1a02007 e1a0100d e3a00001 eb0009a8 eaffff7d
[13793.684600] e288  e320f000 e320f000 e320f000 e320f000 e320f000 e320f000 c0d91a94 c000e95c
[13793.685333] e2a8  c0084a90 c0076030 c000e8c0 c01468e8 c0146964 c01459c4 c01441bc c0093018
[13793.686004] e2c8  c0145a14 c0155798 c0155548 c000e8d0 c01452f8 c0093018 c01553bc c0145574
[13793.686737] e2e8  c00bb7d0 c0093018 c0093018 c01460e8 c008099c c01648c0 c0093018 c00bb8b8
[13793.687439] e308  c00bbcd4 c0093018 c007cde8 c0093018 c0093018 c0085d54 c0093018 c0093018
[13793.688171] 
[13793.688171] R9: 0xecad9f80:
[13793.688324] 9f80  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[13793.689056] 9fa0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[13793.689697] 9fc0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[13793.690430] 9fe0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[13793.691162] a000  00000000 00000002 00000000 eefa8c00 c0de6a80 00000001 00000015 eefa8c00
[13793.691895] a020  c3871700 ecada000 c0d89318 ecaba380 ecabb340 eefaac00 ecadbb4c ecadbab0
[13793.692566] a040  c08b8760 00000000 00000000 00000000 00000000 00000000 01000000 00000000
[13793.693268] a060  4026f840 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[13793.694001] Process v4l_id (pid: 8113, stack limit = 0xecada2f0)
[13793.694062] Stack: (0xecadbf58 to 0xecadc000)
[13793.694214] bf40:                                                       c0096d18 c02d2df4
[13793.694275] bf60: 00020000 ecad0000 00000024 00000100 bee969c2 00000000 a18ee500 00000005
[13793.694397] bf80: c000e2a8 00000000 ecadbfa4 ecadbf98 c01459f4 c0145858 00000000 ecadbfa8
[13793.694550] bfa0: c000e020 c01459d0 bee969c2 00000000 bee969c2 00020000 00000000 00000000
[13793.694672] bfc0: bee969c2 00000000 a18ee500 00000005 00000000 00000000 40078000 00000000
[13793.694764] bfe0: 00000005 bee966b8 401ef6fd 40180706 60000030 bee969c2 00000000 00000000
[13793.694916] [<c0145954>] (do_sys_open+0x108/0x178) from [<c01459f4>] (sys_open+0x30/0x34)
[13793.695069] [<c01459f4>] (sys_open+0x30/0x34) from [<c000e020>] (ret_fast_syscall+0x0/0x30)
[13793.695191] Code: e1a00004 e1a04005 ebfff9e3 ea000015 (e590100c) 
[13793.695344] ---[ end trace 61a5acc2cc582ccb ]---
[13793.695435] Kernel panic - not syncing: Fatal exception
[13793.695588] CPU0: stopping
[13793.695801] [<c00154e4>] (unwind_backtrace+0x0/0xec) from [<c08a936c>] (dump_stack+0x20/0x24)
[13793.696198] [<c08a936c>] (dump_stack+0x20/0x24) from [<c00139a4>] (handle_IPI+0x110/0x1e4)
[13793.696534] [<c00139a4>] (handle_IPI+0x110/0x1e4) from [<c0008688>] (gic_handle_irq+0xb8/0xc4)
[13793.696778] [<c0008688>] (gic_handle_irq+0xb8/0xc4) from [<c08ba680>] (__irq_svc+0x40/0x70)
[13793.697114] Exception stack(0xee33be50 to 0xee33be98)
[13793.697449] be40:                                     c0edc278 00000000 75387538 00010000
[13793.697663] be60: 00000000 00000fff 402582ec 00000124 00000000 c0de6b30 c0edc1c8 ee33bea4
[13793.697999] be80: ee33bea8 ee33be98 c0072cf8 c08b9ed4 40000013 ffffffff
[13793.698365] [<c08ba680>] (__irq_svc+0x40/0x70) from [<c08b9ed4>] (_raw_spin_unlock_irq+0x3c/0x68)
[13793.698579] [<c08b9ed4>] (_raw_spin_unlock_irq+0x3c/0x68) from [<c0072cf8>] (do_syslog+0x21c/0x4bc)
[13793.698945] [<c0072cf8>] (do_syslog+0x21c/0x4bc) from [<c019f088>] (kmsg_read+0x3c/0x64)
[13793.699311] [<c019f088>] (kmsg_read+0x3c/0x64) from [<c0193768>] (proc_reg_read+0x90/0xa8)
[13793.699677] [<c0193768>] (proc_reg_read+0x90/0xa8) from [<c0146814>] (vfs_read+0xb8/0x18c)
[13793.699891] [<c0146814>] (vfs_read+0xb8/0x18c) from [<c0146930>] (sys_read+0x48/0x7c)
[13793.700257] [<c0146930>] (sys_read+0x48/0x7c) from [<c000e020>] (ret_fast_syscall+0x0/0x30)
[13793.700654] wcnss_8960: crash shutdown : 0