kernel-packages team mailing list archive

[Seth Forshee <seth.forshee+lp@xxxxxxxxxxxxx>]

** Description changed:

+ == SRU Justification ==
+ 
+ Impact: Root in a user namespace cannot create new hardlinks to suid
+ files owned by another user even when the inode owner is mapped into
+ that user namespace. This is causing some package upgrades to fail in
+ unprivileged containers.
+ 
+ Fix: Patch from linux-next to allow a user with CAP_FOWNER in a user
+ namespace to link to a suid inode if the inode owner is mapped into the
+ user namespace.
+ 
+ Regression Potential: The main risks here would be security related
+ since the fix is a loosening of the protected_hardlinks sysctl which
+ serves as a mitigation against some classes of security vulnerabilities.
+ However a user which would now be allowed to link directly would
+ generally be able to create links to the same file via other mechanisms
+ already, so it's unlikely that this creates any additional attack
+ surface in practice.
+ 
+ ---
+ 
  Upon trying to do an apt-get upgrade I run into this error:
  
- 
- sudo apt-get dist-upgrade 
+ sudo apt-get dist-upgrade
  Reading package lists... Done
- Building dependency tree       
+ Building dependency tree
  Reading state information... Done
  Calculating upgrade... Done
  The following packages will be upgraded:
-   uuid-runtime
+   uuid-runtime
  1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
  2 not fully installed or removed.
  Need to get 0 B/12.3 kB of archives.
  After this operation, 0 B of additional disk space will be used.
- Do you want to continue? [Y/n] 
+ Do you want to continue? [Y/n]
  (Reading database ... 27622 files and directories currently installed.)
  Preparing to unpack .../uuid-runtime_2.20.1-5.1ubuntu20.7_amd64.deb ...
  Unpacking uuid-runtime (2.20.1-5.1ubuntu20.7) over (2.20.1-5.1ubuntu20.6) ...
  dpkg: error processing archive /var/cache/apt/archives/uuid-runtime_2.20.1-5.1ubuntu20.7_amd64.deb (--unpack):
-  unable to make backup link of `./usr/sbin/uuidd' before installing new version: Operation not permitted
+  unable to make backup link of `./usr/sbin/uuidd' before installing new version: Operation not permitted
  Processing triggers for man-db (2.6.7.1-1ubuntu1) ...
  Errors were encountered while processing:
-  /var/cache/apt/archives/uuid-runtime_2.20.1-5.1ubuntu20.7_amd64.deb
+  /var/cache/apt/archives/uuid-runtime_2.20.1-5.1ubuntu20.7_amd64.deb
  E: Sub-process /usr/bin/dpkg returned an error code (1)
  
  ProblemType: Bug
  DistroRelease: Ubuntu 14.04
  Package: util-linux 2.20.1-5.1ubuntu20.7
  ProcVersionSignature: Ubuntu 3.19.0-26.28~14.04.1-generic 3.19.8-ckt4
  Uname: Linux 3.19.0-26-generic x86_64
  ApportVersion: 2.14.1-0ubuntu3.13
  Architecture: amd64
  Date: Mon Sep 21 19:43:02 2015
  ProcEnviron:
-  TERM=screen-256color
-  PATH=(custom, no user)
-  LANG=en_US.UTF-8
-  SHELL=/bin/bash
+  TERM=screen-256color
+  PATH=(custom, no user)
+  LANG=en_US.UTF-8
+  SHELL=/bin/bash
  SourcePackage: util-linux
  UpgradeStatus: No upgrade log present (probably fresh install)

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https://bugs.launchpad.net/bugs/1498162

Title:
  unable to make backup link of `./usr/sbin/uuidd' before installing new
  version: Operation not permitted

Status in linux package in Ubuntu:
  In Progress
Status in linux source package in Trusty:
  In Progress
Status in linux source package in Vivid:
  In Progress
Status in linux source package in Wily:
  In Progress
Status in linux source package in Xenial:
  In Progress

Bug description:
  == SRU Justification ==

  Impact: Root in a user namespace cannot create new hardlinks to suid
  files owned by another user even when the inode owner is mapped into
  that user namespace. This is causing some package upgrades to fail in
  unprivileged containers.

  Fix: Patch from linux-next to allow a user with CAP_FOWNER in a user
  namespace to link to a suid inode if the inode owner is mapped into
  the user namespace.

  Regression Potential: The main risks here would be security related
  since the fix is a loosening of the protected_hardlinks sysctl which
  serves as a mitigation against some classes of security
  vulnerabilities. However a user which would now be allowed to link
  directly would generally be able to create links to the same file via
  other mechanisms already, so it's unlikely that this creates any
  additional attack surface in practice.

  ---

  Upon trying to do an apt-get upgrade I run into this error:

  sudo apt-get dist-upgrade
  Reading package lists... Done
  Building dependency tree
  Reading state information... Done
  Calculating upgrade... Done
  The following packages will be upgraded:
    uuid-runtime
  1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
  2 not fully installed or removed.
  Need to get 0 B/12.3 kB of archives.
  After this operation, 0 B of additional disk space will be used.
  Do you want to continue? [Y/n]
  (Reading database ... 27622 files and directories currently installed.)
  Preparing to unpack .../uuid-runtime_2.20.1-5.1ubuntu20.7_amd64.deb ...
  Unpacking uuid-runtime (2.20.1-5.1ubuntu20.7) over (2.20.1-5.1ubuntu20.6) ...
  dpkg: error processing archive /var/cache/apt/archives/uuid-runtime_2.20.1-5.1ubuntu20.7_amd64.deb (--unpack):
   unable to make backup link of `./usr/sbin/uuidd' before installing new version: Operation not permitted
  Processing triggers for man-db (2.6.7.1-1ubuntu1) ...
  Errors were encountered while processing:
   /var/cache/apt/archives/uuid-runtime_2.20.1-5.1ubuntu20.7_amd64.deb
  E: Sub-process /usr/bin/dpkg returned an error code (1)

  ProblemType: Bug
  DistroRelease: Ubuntu 14.04
  Package: util-linux 2.20.1-5.1ubuntu20.7
  ProcVersionSignature: Ubuntu 3.19.0-26.28~14.04.1-generic 3.19.8-ckt4
  Uname: Linux 3.19.0-26-generic x86_64
  ApportVersion: 2.14.1-0ubuntu3.13
  Architecture: amd64
  Date: Mon Sep 21 19:43:02 2015
  ProcEnviron:
   TERM=screen-256color
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  SourcePackage: util-linux
  UpgradeStatus: No upgrade log present (probably fresh install)

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