kernel-packages team mailing list archive

[John Johansen <john.johansen@xxxxxxxxxxxxx>]

Alban, I'd be interested in seeing what you patch to sd_load_buffer()
looks like. We have just landed a patch upstream to fix the multiple
write problem for 2.8, 29, and dev.

There are two things to note about profile loads that have multiple profiles in them.
1. Older kernels don't actually support it.
2. The load is treated as an atomic set. That is either all profiles within the set must load/replace successfully or none of them will

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https://bugs.launchpad.net/bugs/1317545

Title:
  AppArmor: general protection fault: 0000 [#1] SMP

Status in “linux” package in Ubuntu:
  Confirmed

Bug description:
  How to reproduce it:

  1. Create a concatenated cache: (it might not be a correct thing to
  do, but the kernel is not supposed to crash anyway)

  . /lib/apparmor/functions
  recache_profiles
  rm -f "${PROFILES}"/cache/.ubercache
  for i in "${PROFILES}"/cache/*; do
    cat "$i" >> "${PROFILES}"/cache/.ubercache
  done

  2. sudo /etc/init.d/apparmor teardown

  3. sudo /sbin/apparmor_parser --add -B /etc/apparmor.d/cache/.ubercache
     => $?=239 (EEXIST)
  The issue with EEXIST is  how apparmor_parser uploads the binary profiles to the kernel in parser/parser_interface.c sd_load_buffer().

  If /etc/apparmor.d/cache/.ubercache contains n profiles,
  sd_load_buffer() was performing n write() to
  /sys/kernel/security/apparmor/.load in this way:

  1. write() with all profiles in the range [1, n]
  2. write() with all profiles in the range [2, n]
  3. write() with all profiles in the range [3, n]
  ...
  n. write() with the n-th profile

  The first write() is successful and the n-1 other write() return
  EEXIST because the profiles is already uploaded in the first write().

  Comment near parser/parser_interface.c sd_load_buffer():
  /* bleah the kernel should just loop and do multiple load, but to support
   * older systems we need to do this

  4. sudo /sbin/apparmor_parser --replace -B /etc/apparmor.d/cache/.ubercache
     => segmentation fault (because of the kernel crash)

  5. sudo /sbin/apparmor_parser --replace -B /etc/apparmor.d/cache/.ubercache
     => freeze in state "D"

  ProblemType: KernelOops
  DistroRelease: Ubuntu 14.04
  Package: linux-image-3.13.0-24-generic 3.13.0-24.47
  ProcVersionSignature: Ubuntu 3.13.0-24.47-generic 3.13.9
  Uname: Linux 3.13.0-24-generic x86_64
  Annotation: Your system might become unstable now and might need to be restarted.
  ApportVersion: 2.13.3-0ubuntu1
  Architecture: amd64
  AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
  CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
  Date: Thu May  8 15:43:47 2014
  Failure: oops
  HibernationDevice: RESUME=UUID=ae00639c-b206-4387-b731-1a52e58547cf
  InstallationDate: Installed on 2014-03-21 (48 days ago)
  InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140321)
  IwConfig:
   eth0      no wireless extensions.
   
   lo        no wireless extensions.
  Lsusb:
   Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
   Bus 002 Device 002: ID 80ee:0021 VirtualBox USB Tablet
   Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
  MachineType: innotek GmbH VirtualBox
  ProcFB: 0 VESA VGA
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-24-generic root=UUID=1ec94169-4f22-4000-90d6-c14f61a59998 ro quiet splash vt.handoff=7
  PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon.
  RelatedPackageVersions: kerneloops-daemon 0.12+git20090217-3ubuntu6
  RfKill:
   
  SourcePackage: linux
  Title: general protection fault: 0000 [#1] SMP
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 12/01/2006
  dmi.bios.vendor: innotek GmbH
  dmi.bios.version: VirtualBox
  dmi.board.name: VirtualBox
  dmi.board.vendor: Oracle Corporation
  dmi.board.version: 1.2
  dmi.chassis.type: 1
  dmi.chassis.vendor: Oracle Corporation
  dmi.modalias: dmi:bvninnotekGmbH:bvrVirtualBox:bd12/01/2006:svninnotekGmbH:pnVirtualBox:pvr1.2:rvnOracleCorporation:rnVirtualBox:rvr1.2:cvnOracleCorporation:ct1:cvr:
  dmi.product.name: VirtualBox
  dmi.product.version: 1.2
  dmi.sys.vendor: innotek GmbH

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