For me I have a similar issues...

the log says:

Apr 17 02:29:36 trusty-01 kernel: [70827.909934] ------------[ cut here ]------------
Apr 17 02:29:36 trusty-01 kernel: [70827.909960] WARNING: CPU: 0 PID: 2985 at /build/buildd/linux-3.13.0/security/apparmor/lsm.c:839 apparmor_unix_may_send+0x16c/0x180()
Apr 17 02:29:36 trusty-01 kernel: [70827.909964] AppArmor WARN apparmor_unix_may_send: ((!aa_label_is_subset(cxt->label, label))): 
Apr 17 02:29:36 trusty-01 kernel: [70827.909968] Modules linked in: kvm_intel kvm cirrus snd_hda_intel ttm snd_hda_codec drm_kms_helper snd_hwdep psmouse serio_raw snd_pcm drm snd_page_alloc snd_timer syscopyarea snd soundcore sysfillrect sysimgblt i2c_piix4 lp parport mac_hid 8139too 8139cp mii floppy
Apr 17 02:29:36 trusty-01 kernel: [70827.910014] CPU: 0 PID: 2985 Comm: dhcpd Tainted: G        W    3.13.0-24-generic #46-Ubuntu
Apr 17 02:29:36 trusty-01 kernel: [70827.910018] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Apr 17 02:29:36 trusty-01 kernel: [70827.910022]  0000000000000009 ffff880000063bd0 ffffffff81715a64 ffff880000063c18
Apr 17 02:29:36 trusty-01 kernel: [70827.910030]  ffff880000063c08 ffffffff810676bd ffff88003e00a430 ffff88003d618000
Apr 17 02:29:36 trusty-01 kernel: [70827.910036]  ffff88003b33f010 ffff88003d70f400 ffff88003c1a8000 ffff880000063c68
Apr 17 02:29:36 trusty-01 kernel: [70827.910043] Call Trace:
Apr 17 02:29:36 trusty-01 kernel: [70827.910056]  [<ffffffff81715a64>] dump_stack+0x45/0x56
Apr 17 02:29:36 trusty-01 kernel: [70827.910066]  [<ffffffff810676bd>] warn_slowpath_common+0x7d/0xa0
Apr 17 02:29:36 trusty-01 kernel: [70827.910072]  [<ffffffff8106772c>] warn_slowpath_fmt+0x4c/0x50
Apr 17 02:29:36 trusty-01 kernel: [70827.910080]  [<ffffffff8130ed5c>] apparmor_unix_may_send+0x16c/0x180
Apr 17 02:29:36 trusty-01 kernel: [70827.910089]  [<ffffffff812cf876>] security_unix_may_send+0x16/0x20
Apr 17 02:29:36 trusty-01 kernel: [70827.910097]  [<ffffffff816b2575>] unix_dgram_sendmsg+0x2a5/0x620
Apr 17 02:29:36 trusty-01 kernel: [70827.910108]  [<ffffffff816024eb>] sock_sendmsg+0x8b/0xc0
Apr 17 02:29:36 trusty-01 kernel: [70827.910116]  [<ffffffff81602691>] SYSC_sendto+0x121/0x1c0
Apr 17 02:29:36 trusty-01 kernel: [70827.910125]  [<ffffffff8109dd84>] ? vtime_account_user+0x54/0x60
Apr 17 02:29:36 trusty-01 kernel: [70827.910137]  [<ffffffff81020d35>] ? syscall_trace_enter+0x145/0x250
Apr 17 02:29:36 trusty-01 kernel: [70827.910145]  [<ffffffff8160319e>] SyS_sendto+0xe/0x10
Apr 17 02:29:36 trusty-01 kernel: [70827.910154]  [<ffffffff8172663f>] tracesys+0xe1/0xe6
Apr 17 02:29:36 trusty-01 kernel: [70827.910158] ---[ end trace 0b1a05a3a90a9dc7 ]---
Apr 17 02:29:46 trusty-01 kernel: [70838.210778] ------------[ cut here ]------------
Apr 17 02:29:46 trusty-01 kernel: [70838.210791] WARNING: CPU: 0 PID: 2985 at /build/buildd/linux-3.13.0/security/apparmor/lsm.c:839 apparmor_unix_may_send+0x16c/0x180()
Apr 17 02:29:46 trusty-01 kernel: [70838.210793] AppArmor WARN apparmor_unix_may_send: ((!aa_label_is_subset(cxt->label, label))): 
Apr 17 02:29:46 trusty-01 kernel: [70838.210794] Modules linked in: kvm_intel kvm cirrus snd_hda_intel ttm snd_hda_codec drm_kms_helper snd_hwdep psmouse serio_raw snd_pcm drm snd_page_alloc snd_timer syscopyarea snd soundcore sysfillrect sysimgblt i2c_piix4 lp parport mac_hid 8139too 8139cp mii floppy
Apr 17 02:29:46 trusty-01 kernel: [70838.210817] CPU: 0 PID: 2985 Comm: dhcpd Tainted: G        W    3.13.0-24-generic #46-Ubuntu
Apr 17 02:29:46 trusty-01 kernel: [70838.210818] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Apr 17 02:29:46 trusty-01 kernel: [70838.210820]  0000000000000009 ffff880000063bd0 ffffffff81715a64 ffff880000063c18
Apr 17 02:29:46 trusty-01 kernel: [70838.210823]  ffff880000063c08 ffffffff810676bd ffff88003e00a430 ffff88003d618000
Apr 17 02:29:46 trusty-01 kernel: [70838.210826]  ffff88003b33f010 ffff88003d70f400 ffff88003c1a8000 ffff880000063c68
Apr 17 02:29:46 trusty-01 kernel: [70838.210829] Call Trace:
Apr 17 02:29:46 trusty-01 kernel: [70838.210835]  [<ffffffff81715a64>] dump_stack+0x45/0x56
Apr 17 02:29:46 trusty-01 kernel: [70838.210840]  [<ffffffff810676bd>] warn_slowpath_common+0x7d/0xa0
Apr 17 02:29:46 trusty-01 kernel: [70838.210842]  [<ffffffff8106772c>] warn_slowpath_fmt+0x4c/0x50
Apr 17 02:29:46 trusty-01 kernel: [70838.210846]  [<ffffffff8130ed5c>] apparmor_unix_may_send+0x16c/0x180
Apr 17 02:29:46 trusty-01 kernel: [70838.210850]  [<ffffffff812cf876>] security_unix_may_send+0x16/0x20
Apr 17 02:29:46 trusty-01 kernel: [70838.210854]  [<ffffffff816b2575>] unix_dgram_sendmsg+0x2a5/0x620
Apr 17 02:29:46 trusty-01 kernel: [70838.210860]  [<ffffffff816024eb>] sock_sendmsg+0x8b/0xc0
Apr 17 02:29:46 trusty-01 kernel: [70838.210863]  [<ffffffff81602691>] SYSC_sendto+0x121/0x1c0
Apr 17 02:29:46 trusty-01 kernel: [70838.210867]  [<ffffffff8109dd84>] ? vtime_account_user+0x54/0x60
Apr 17 02:29:46 trusty-01 kernel: [70838.210873]  [<ffffffff81020d35>] ? syscall_trace_enter+0x145/0x250
Apr 17 02:29:46 trusty-01 kernel: [70838.210877]  [<ffffffff8160319e>] SyS_sendto+0xe/0x10
Apr 17 02:29:46 trusty-01 kernel: [70838.210881]  [<ffffffff8172663f>] tracesys+0xe1/0xe6
Apr 17 02:29:46 trusty-01 kernel: [70838.210883] ---[ end trace 0b1a05a3a90a9dc8 ]---
Apr 17 02:30:02 trusty-01 kernel: [70854.080466] ------------[ cut here ]------------