Here is the last thing I have before freezing and just after I rebooted (from
journal with systemd, no more dmesg). As you'll see, there is nothing there.
I'll look into other logs just in case.

Oct 26 19:57:08 Xander kernel: kworker/u16:1 (18455) used greatest stack depth:
3472 bytes left
Oct 26 19:58:13 Xander kernel: r8712u 1-1:1.0 wlan0:
r8712_got_addbareq_event_callback: mac = 96:0c:6d:f1:2e:b2, seq = 24336
Oct 26 19:58:18 Xander kernel: r8712u 1-1:1.0 wlan0:
r8712_got_addbareq_event_callback: mac = 96:0c:6d:f1:2e:b2, seq = 24352
Oct 26 19:58:23 Xander kernel: r8712u 1-1:1.0 wlan0:
r8712_got_addbareq_event_callback: mac = 96:0c:6d:f1:2e:b2, seq = 24400
Oct 26 19:58:33 Xander kernel: r8712u 1-1:1.0 wlan0:
r8712_got_addbareq_event_callback: mac = 96:0c:6d:f1:2e:b2, seq = 24432
Oct 26 19:58:36 Xander dbus-daemon[2858]: dbus[2858]: [system] Activating via
systemd: service name='org.freedesktop.ModemMa
Oct 26 19:58:36 Xander dbus-daemon[2858]: dbus[2858]: [system] Activation via
systemd failed for unit 'dbus-org.freedesktop.
Oct 26 19:58:36 Xander dbus[2858]: [system] Activating via systemd: service
name='org.freedesktop.ModemManager1' unit='dbus-
Oct 26 19:58:36 Xander dbus[2858]: [system] Activation via systemd failed for
unit 'dbus-org.freedesktop.ModemManager1.servi
Oct 26 19:58:43 Xander kernel: r8712u 1-1:1.0 wlan0:
r8712_got_addbareq_event_callback: mac = 96:0c:6d:f1:2e:b2, seq = 24448
Oct 26 19:59:18 Xander kernel: r8712u 1-1:1.0 wlan0:
r8712_got_addbareq_event_callback: mac = 96:0c:6d:f1:2e:b2, seq = 25936
Oct 26 19:59:43 Xander kernel: r8712u 1-1:1.0 wlan0:
r8712_got_addbareq_event_callback: mac = 96:0c:6d:f1:2e:b2, seq = 26112
Oct 26 20:00:18 Xander kernel: r8712u 1-1:1.0 wlan0:
r8712_got_addbareq_event_callback: mac = 96:0c:6d:f1:2e:b2, seq = 26624
Oct 26 20:00:36 Xander dbus-daemon[2858]: dbus[2858]: [system] Activating via
systemd: service name='org.freedesktop.ModemMa
Oct 26 20:00:36 Xander dbus[2858]: [system] Activating via systemd: service
name='org.freedesktop.ModemManager1' unit='dbus-
Oct 26 20:00:36 Xander dbus[2858]: [system] Activation via systemd failed for
unit 'dbus-org.freedesktop.ModemManager1.servi
Oct 26 20:00:36 Xander dbus-daemon[2858]: dbus[2858]: [system] Activation via
systemd failed for unit 'dbus-org.freedesktop.
Oct 26 20:00:46 Xander kernel: r8712u 1-1:1.0 wlan0:
r8712_got_addbareq_event_callback: mac = 96:0c:6d:f1:2e:b2, seq = 26848
Oct 26 20:00:56 Xander kernel: r8712u 1-1:1.0 wlan0:
r8712_got_addbareq_event_callback: mac = 96:0c:6d:f1:2e:b2, seq = 26944
Oct 26 20:01:01 Xander crond[22879]: pam_unix(crond:session): session opened
for user root by (uid=0)
Oct 26 20:01:01 Xander CROND[22880]: (root) CMD (run-parts /etc/cron.hourly)
Oct 26 20:01:01 Xander CROND[22879]: pam_unix(crond:session): session closed
for user root
Oct 26 20:01:03 Xander kernel: r8712u 1-1:1.0 wlan0:
r8712_got_addbareq_event_callback: mac = 96:0c:6d:f1:2e:b2, seq = 27040
Oct 26 20:01:13 Xander kernel: r8712u 1-1:1.0 wlan0:
r8712_got_addbareq_event_callback: mac = 96:0c:6d:f1:2e:b2, seq = 27120
Oct 26 20:01:33 Xander kernel: r8712u 1-1:1.0 wlan0:
r8712_got_addbareq_event_callback: mac = 96:0c:6d:f1:2e:b2, seq = 27296
Oct 26 20:01:43 Xander kernel: r8712u 1-1:1.0 wlan0:
r8712_got_addbareq_event_callback: mac = 96:0c:6d:f1:2e:b2, seq = 27360
Oct 26 20:02:03 Xander kernel: r8712u 1-1:1.0 wlan0:
r8712_got_addbareq_event_callback: mac = 96:0c:6d:f1:2e:b2, seq = 29760
Oct 26 20:02:36 Xander dbus-daemon[2858]: dbus[2858]: [system] Activating via
systemd: service name='org.freedesktop.ModemMa
Oct 26 20:02:36 Xander dbus[2858]: [system] Activating via systemd: service
name='org.freedesktop.ModemManager1' unit='dbus-
Oct 26 20:02:36 Xander dbus[2858]: [system] Activation via systemd failed for
unit 'dbus-org.freedesktop.ModemManager1.servi
Oct 26 20:02:36 Xander dbus-daemon[2858]: dbus[2858]: [system] Activation via
systemd failed for unit 'dbus-org.freedesktop.
Oct 26 20:02:44 Xander kernel: r8712u 1-1:1.0 wlan0:
r8712_got_addbareq_event_callback: mac = 96:0c:6d:f1:2e:b2, seq = 37984
-- Reboot --
Oct 26 20:19:34 Xander systemd-journal[1936]: Runtime journal is using 1.3M
(max 395.4M, leaving 593.1M of free 3.8G, curren
Oct 26 20:19:34 Xander systemd-journal[1936]: Runtime journal is using 1.3M
(max 395.4M, leaving 593.1M of free 3.8G, curren
Oct 26 20:19:34 Xander kernel: Initializing cgroup subsys cpuset
Oct 26 20:19:34 Xander kernel: Initializing cgroup subsys cpu
Oct 26 20:19:34 Xander kernel: Initializing cgroup subsys cpuacct
Oct 26 20:19:34 Xander kernel: Linux version
3.12.0-rc6-VANILLA-00284-ge6036c0-dirty (dema1701@Xander) (gcc version 4.8.2 (G
Oct 26 20:19:34 Xander kernel: Command line:
BOOT_IMAGE=/vmlinuz-3.12.0-rc6-VANILLA-00284-ge6036c0-dirty root=UUID=04e7cc91-
Oct 26 20:19:34 Xander kernel: e820: BIOS-provided physical RAM map: