cupsd tainted:PF messages

[rjvbb]

I've noticed that the new kernel I built (3.13.9 as obtained through apt-get source linux-image) spews high-frequency errors in the syslog about cupsd being tainted:

May 12 13:39:53 kubux kernel: [10446.713357] ------------[ cut here ]------------May 12 13:39:53 kubux kernel: [10446.713381] WARNING: CPU: 0 PID: 3844 at security/apparmor/file.c:489 aa_file_perm+0x37a/0x3c0()
May 12 13:39:53 kubux kernel: [10446.713392] AppArmor WARN __file_path_perm: ((preempt_count() <= 0)): __get_buffer without preempt disabled
May 12 13:39:53 kubux kernel: [10446.713395] Modules linked in: michael_mic(F) arc4(F) rfcomm(F) bnep(F) bluetooth(F) binfmt_misc(F) nfsd(F) auth_rpcgss(F) nfs_acl(F) nfs(F) lockd(F) sunrpc(F) fscache(F) joydev(F) uvcvideo(F) videobuf2_vmalloc(F) videobuf2_memops(F) videobuf2_core(F) acer_wmi(F) videodev(F) media(F) sparse_keymap(F) snd_hda_codec_conexant(F) snd_hda_codec_hdmi(F) snd_hda_intel(F) snd_hda_codec(F) snd_hwdep(F) snd_pcm(F) snd_page_alloc(F) snd_seq_midi(F) snd_seq_midi_event(F) snd_rawmidi(F) kvm_amd(F) kvm(F) snd_seq(F) lib80211_crypt_tkip(F) snd_seq_device(F) snd_timer(F) wl(POF) lib80211(F) psmouse(F) serio_raw(F) k10temp(F) cfg80211(F) sp5100_tco(F) snd(F) i2c_piix4(F) soundcore(F) parport_pc(F) ppdev(F) mac_hid(F) lp(F) parport(F) zfs(POF) zunicode(POF) zavl(POF) zcommon(POF) znvpair(POF) spl(OF) sd_mod(F) radeon(F) i2c_algo_bit(F) ttm(F) atl1c(F) drm_kms_helper(F) ahci(F) drm(F) libahci(F) video(F)
May 12 13:39:53 kubux kernel: [10446.713510] CPU: 0 PID: 3844 Comm: cupsd Tainted: PF       W  O 3.13.9-ck1-kubuntu-ck-amdf10-rjvb #3
May 12 13:39:53 kubux kernel: [10446.713515] Hardware name: Acer AO722/JE10-BZ, BIOS V1.11 09/25/2012
May 12 13:39:53 kubux kernel: [10446.713518]  ffffffff814e1bda ffff8801b6b55db8 ffffffff81a5e471 ffffffff81e98467
May 12 13:39:53 kubux kernel: [10446.713545]  ffff8801b6b55e30 ffffffff81085f43 ffffffff81e9f7e0 ffff880100000020
May 12 13:39:53 kubux kernel: [10446.713554]  ffff8801b6b55e40 ffff8801b6b55de8 ffff8801b6b55e50 ffff8801b6b55e78
May 12 13:39:53 kubux kernel: [10446.713570] Call Trace:
May 12 13:39:53 kubux kernel: [10446.713585]  [<ffffffff814e1bda>] ? aa_file_perm+0x37a/0x3c0
May 12 13:39:53 kubux kernel: [10446.713598]  [<ffffffff81a5e471>] dump_stack+0x4e/0x7a
May 12 13:39:53 kubux kernel: [10446.713611]  [<ffffffff81085f43>] warn_slowpath_fmt+0xa3/0x120
May 12 13:39:53 kubux kernel: [10446.713621]  [<ffffffff814e1bda>] aa_file_perm+0x37a/0x3c0
May 12 13:39:53 kubux kernel: [10446.713630]  [<ffffffff814df31c>] apparmor_file_permission+0x5c/0x160
May 12 13:39:53 kubux kernel: [10446.713639]  [<ffffffff814893e3>] security_file_permission+0x23/0xe0
May 12 13:39:53 kubux kernel: [10446.713648]  [<ffffffff8124cd9c>] SyS_write+0xbc/0x440
May 12 13:39:53 kubux kernel: [10446.713657]  [<ffffffff81a72f2d>] system_call_fastpath+0x1a/0x1f
May 12 13:39:53 kubux kernel: [10446.713662] ---[ end trace 4279ec7a520994e0 ]---

This looks like a file permissions issue (PF) but the question is: on what file(s)? I see nothing wrong anywhere, but the error remains even after reinstalling cups-daemon (which contains /usr/sbin/cupsd).

For now I've disabled apparmor on cupsd by adding the appropriate entry to /etc/apparmor.d/disable but of course I'd like to find a better solution.

If of course there's any reason to have an apparmor profile for cupsd - thoughts on that?