Commits on Apr 7, 2017

1. 9pfs: fix O_PATH build break with older glibc versions …

   When O_PATH is used with O_DIRECTORY, it only acts as an optimization: the
   openat() syscall simply finds the name in the VFS, and doesn't trigger the
   underlying filesystem.
   
   On systems that don't define O_PATH, because they have glibc version 2.13
   or older for example, we can safely omit it. We don't want to deactivate
   O_PATH globally though, in case it is used without O_DIRECTORY. The is done
   with a dedicated macro.
   
   Systems without O_PATH may thus fail to resolve names that involve
   unreadable directories, compared to newer systems succeeding, but such
   corner case failure is our only option on those older systems to avoid
   the security hole of chasing symlinks inappropriately.
   
   Signed-off-by: Greg Kurz <groug@kaod.org>
   Reviewed-by: Eric Blake <eblake@redhat.com>
   (added last paragraph to changelog as suggested by Eric Blake)
   Signed-off-by: Greg Kurz <groug@kaod.org>
   
   (cherry picked from commit 918112c)
   Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
   Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

   

   gkurz authored and bergwolf committed Apr 7, 2017
   Configuration menu

   • View commit details
   • Copy full SHA for 765f98d
   • Browse repository at this point

   Copy the full SHA

   765f98d View commit details

   Browse the repository at this point in the history

2. 9pfs: fix vulnerability in openat_dir() and local_unlinkat_common() …

   We should pass O_NOFOLLOW otherwise openat() will follow symlinks and make
   QEMU vulnerable.
   
   While here, we also fix local_unlinkat_common() to use openat_dir() for
   the same reasons (it was a leftover in the original patchset actually).
   
   This fixes CVE-2016-9602.
   
   Signed-off-by: Greg Kurz <groug@kaod.org>
   Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
   Reviewed-by: Eric Blake <eblake@redhat.com>
   (cherry picked from commit b003fc0)
   Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
   Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

   

   gkurz authored and bergwolf committed Apr 7, 2017
   Configuration menu

   • View commit details
   • Copy full SHA for b42cf51
   • Browse repository at this point

   Copy the full SHA

   b42cf51 View commit details

   Browse the repository at this point in the history