Ubuntu freezes after upgrade when logging in

I have just made a regular upgrade on my ubuntu vivid machine. After doing so the system freezes after login. I tried different accounts and different window managers (xmonad and gnome fallback), but it freezes every time a few seconds after login.

Because of the freeze I cannot report this bug using ubuntu-bug. So tell me what files you need for debugging this (I have ssh command line access to the frozen machine).

It might be relevant that the mouse pointer changes from a white one to a smaller black one when it freezes.

After freezing I cannot switch to console via Ctrl+Alt+F1.

I tried to narrow it down by switching to the previous kernel

3.19.0-30 works
3.19.0-31 freezes

Then I diffed the output of dmesg with and without freeze. The relevant part (when it is freezing) seems to be:

[ 221.246755] BUG: unable to handle kernel paging request at ffffebe000000000
[ 221.246799] IP: [<ffffffff811d5f59>] kmem_cache_free+0x69/0x200
[ 221.246827] PGD 0
[ 221.246839] Oops: 0000 [#1] SMP
[ 221.246857] Modules linked in: vmw_vsock_vmci_transport vsock vmw_vmci pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) binfmt_misc zram lz4_compress snd_hda_codec_hdmi snd_hda_codec_idt snd_hda_codec_generic snd_hda_intel snd_hda_controller snd_hda_codec snd_hwdep snd_pcm gpio_ich dell_wmi sparse_keymap dell_rbtn snd_seq_midi snd_seq_midi_event dell_laptop dcdbas i8k coretemp arc4 snd_rawmidi pcmcia kvm_intel iwldvm mac80211 kvm snd_seq joydev serio_raw iwlwifi snd_seq_device snd_timer lpc_ich yenta_socket cfg80211 pcmcia_rsrc pcmcia_core snd soundcore shpchp 8250_fintek mac_hid parport_pc ppdev lp parport autofs4 sdhci_pci firewire_ohci sdhci firewire_core psmouse crc_itu_t ahci libahci i915 video i2c_algo_bit wmi drm_kms_helper drm e1000e ptp pps_core
[ 221.247228] CPU: 1 PID: 2824 Comm: pulseaudio Tainted: G OE 3.19.0-31-generic #35-Ubuntu
[ 221.247260] Hardware name: Dell Inc. Latitude E6400 /0G983N, BIOS A34 06/04/2013
[ 221.247292] task: ffff88011a1089d0 ti: ffff8800d4068000 task.ti: ffff8800d4068000
[ 221.247319] RIP: 0010:[<ffffffff811d5f59>] [<ffffffff811d5f59>] kmem_cache_free+0x69/0x200
[ 221.247351] RSP: 0018:ffff8800d406bdd8 EFLAGS: 00010286
[ 221.247373] RAX: 000001e000000000 RBX: 0000000000000000 RCX: 00007f5c20ba4000
[ 221.247399] RDX: 000077ff80000000 RSI: 0000000000000000 RDI: ffff88011b087400
[ 221.247424] RBP: ffff8800d406bdf8 R08: 0000000000000000 R09: ffffffff8123b4f2
[ 221.247449] R10: ffff88011a769321 R11: ffffebe000000000 R12: ffff88011b087400
[ 221.247475] R13: ffff8800d40068e8 R14: 0000000000000000 R15: ffff8800d4006858
[ 221.247500] FS: 00007f648780e780(0000) GS:ffff88011fd00000(0000) knlGS:0000000000000000
[ 221.247533] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 221.247554] CR2: ffffebe000000000 CR3: 00000000d4063000 CR4: 00000000000407e0
[ 221.247579] Stack:
[ 221.247589] 0000000000000000 0000000000000000 ffff8800d40068a8 ffff8800d40068e8
[ 221.247621] ffff8800d406be28 ffffffff8123b4f2 0000000000000008 ffff8800d40068a8
[ 221.247654] 0000000000000000 0000000000000055 ffff8800d406be58 ffffffff8123b534
[ 221.247686] Call Trace:
[ 221.247700] [<ffffffff8123b4f2>] ep_unregister_pollwait.isra.7+0x72/0x90
[ 221.247725] [<ffffffff8123b534>] ep_remove+0x24/0xd0
[ 221.247744] [<ffffffff8123c2bf>] eventpoll_release_file+0x5f/0xa0
[ 221.247771] [<ffffffff811f6c58>] __fput+0x1d8/0x250
[ 221.247793] [<ffffffff811f6d1e>] ____fput+0xe/0x10
[ 221.247813] [<ffffffff81093f07>] task_work_run+0xb7/0xf0
[ 221.247835] [<ffffffff81014fe7>] do_notify_resume+0x97/0xb0
[ 221.247861] [<ffffffff817cc1ef>] int_signal+0x12/0x17
[ 221.247883] Code: ff 77 00 00 49 bb 00 00 00 00 00 ea ff ff 48 01 d8 48 0f 42 15 c9 40 a4 00 4c 8b 4d 08 48 01 d0 48 c1 e8 0c 48 c1 e0 06 49 01 c3 <49> 8b 03 f6 c4 80 0f 85 53 01 00 00 4c 8b 17 65 4c 03 15 f8 41
[ 221.248052] RIP [<ffffffff811d5f59>] kmem_cache_free+0x69/0x200
[ 221.248081] RSP <ffff8800d406bdd8>
[ 221.248094] CR2: ffffebe000000000
[ 221.250545] ---[ end trace a8b6ee313300be00 ]---

The relevant part of the upgrade log reads like:

Aptitude 0.6.11: log report
Mi, Okt 7 2015 20:42:12 +0200

IMPORTANT: this log only lists intended actions; actions which fail due to
dpkg problems may not be completed.

Will install 21 packages, and remove 0 packages.
289 MB of disk space will be used
===============================================================================
[INSTALL, DEPENDENCIES] linux-headers-3.19.0-31:amd64
[INSTALL, DEPENDENCIES] linux-headers-3.19.0-31-generic:amd64
[INSTALL, DEPENDENCIES] linux-image-3.19.0-31-generic:amd64
[INSTALL, DEPENDENCIES] linux-image-extra-3.19.0-31-generic:amd64
[UPGRADE] chromium-browser:amd64 45.0.2454.85-0ubuntu0.15.04.1.1181 -> 45.0.2454.101-0ubuntu0.15.04.1.1183
[UPGRADE] chromium-browser-l10n:amd64 45.0.2454.85-0ubuntu0.15.04.1.1181 -> 45.0.2454.101-0ubuntu0.15.04.1.1183
[UPGRADE] chromium-codecs-ffmpeg-extra:amd64 45.0.2454.85-0ubuntu0.15.04.1.1181 -> 45.0.2454.101-0ubuntu0.15.04.1.1183
[UPGRADE] firefox:amd64 41.0+build3-0ubuntu0.15.04.1 -> 41.0.1+build2-0ubuntu0.15.04.2
[UPGRADE] firefox-locale-en:amd64 41.0+build3-0ubuntu0.15.04.1 -> 41.0.1+build2-0ubuntu0.15.04.2
[UPGRADE] geogebra5:amd64 5.0.156.0-43185 -> 5.0.158.0-43263
[UPGRADE] libspice-server1:amd64 0.12.5-1ubuntu0.1 -> 0.12.5-1ubuntu0.2
[UPGRADE] linux-generic:amd64 3.19.0.30.29 -> 3.19.0.31.30
[UPGRADE] linux-headers-3.19.0-30:amd64 3.19.0-30.33 -> 3.19.0-30.34
[UPGRADE] linux-headers-3.19.0-30-generic:amd64 3.19.0-30.33 -> 3.19.0-30.34
[UPGRADE] linux-headers-generic:amd64 3.19.0.30.29 -> 3.19.0.31.30
[UPGRADE] linux-image-3.19.0-30-generic:amd64 3.19.0-30.33 -> 3.19.0-30.34
[UPGRADE] linux-image-extra-3.19.0-30-generic:amd64 3.19.0-30.33 -> 3.19.0-30.34
[UPGRADE] linux-image-generic:amd64 3.19.0.30.29 -> 3.19.0.31.30
[UPGRADE] linux-libc-dev:amd64 3.19.0-30.33 -> 3.19.0-31.35
[UPGRADE] oxideqt-codecs-extra:amd64 1.9.1-0ubuntu0.15.04.1 -> 1.9.5-0ubuntu0.15.04.1
[UPGRADE] thunderbird:amd64 1:38.2.0+build1-0ubuntu0.15.04.1 -> 1:38.3.0+build1-0ubuntu0.15.04.1
===============================================================================

I also diffed the output of Xorg.0.log but there doesn't seem any differences.

Finally I installed the mainline kernel v4.1-rc2 (http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.1-rc2-vivid/) which also worked (but introduced another problem: the speakers crackles or rustle (my english is not good enough to get the correct word for it) some times at boot and after login, which is annoying. So it is not a good idea to use this mainline kernel for me.

Should I go with the old kernel and wait for a patch? What do you suggest?