1. 01 May, 2013 2 commits
  2. 04 Mar, 2013 1 commit
    • Eric W. Biederman's avatar
      fs: Limit sys_mount to only request filesystem modules. · 7f78e035
      Eric W. Biederman authored
      Modify the request_module to prefix the file system type with "fs-"
      and add aliases to all of the filesystems that can be built as modules
      to match.
      
      A common practice is to build all of the kernel code and leave code
      that is not commonly needed as modules, with the result that many
      users are exposed to any bug anywhere in the kernel.
      
      Looking for filesystems with a fs- prefix limits the pool of possible
      modules that can be loaded by mount to just filesystems trivially
      making things safer with no real cost.
      
      Using aliases means user space can control the policy of which
      filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
      with blacklist and alias directives.  Allowing simple, safe,
      well understood work-arounds to known problematic software.
      
      This also addresses a rare but unfortunate problem where the filesystem
      name is not the same as it's module name and module auto-loading
      would not work.  While writing this patch I saw a handful of such
      cases.  The most significant being autofs that lives in the module
      autofs4.
      
      This is relevant to user namespaces because we can reach the request
      module in get_fs_type() without having any special permissions, and
      people get uncomfortable when a user specified string (in this case
      the filesystem type) goes all of the way to request_module.
      
      After having looked at this issue I don't think there is any
      particular reason to perform any filtering or permission checks beyond
      making it clear in the module request that we want a filesystem
      module.  The common pattern in the kernel is to call request_module()
      without regards to the users permissions.  In general all a filesystem
      module does once loaded is call register_filesystem() and go to sleep.
      Which means there is not much attack surface exposed by loading a
      filesytem module unless the filesystem is mounted.  In a user
      namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
      which most filesystems do not set today.
      Acked-by: default avatarSerge Hallyn <serge.hallyn@canonical.com>
      Acked-by: default avatarKees Cook <keescook@chromium.org>
      Reported-by: default avatarKees Cook <keescook@google.com>
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      7f78e035
  3. 23 Feb, 2013 1 commit
  4. 21 Jan, 2013 1 commit
  5. 20 Dec, 2012 1 commit
  6. 03 Oct, 2012 1 commit
  7. 21 Sep, 2012 1 commit
  8. 20 Aug, 2012 1 commit
    • Tejun Heo's avatar
      workqueue: deprecate flush[_delayed]_work_sync() · 43829731
      Tejun Heo authored
      flush[_delayed]_work_sync() are now spurious.  Mark them deprecated
      and convert all users to flush[_delayed]_work().
      
      If you're cc'd and wondering what's going on: Now all workqueues are
      non-reentrant and the regular flushes guarantee that the work item is
      not pending or running on any CPU on return, so there's no reason to
      use the sync flushes at all and they're going away.
      
      This patch doesn't make any functional difference.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Ian Campbell <ian.campbell@citrix.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Mattia Dongili <malattia@linux.it>
      Cc: Kent Yoder <key@linux.vnet.ibm.com>
      Cc: David Airlie <airlied@linux.ie>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Karsten Keil <isdn@linux-pingi.de>
      Cc: Bryan Wu <bryan.wu@canonical.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Alasdair Kergon <agk@redhat.com>
      Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
      Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: linux-wireless@vger.kernel.org
      Cc: Anton Vorontsov <cbou@mail.ru>
      Cc: Sangbeom Kim <sbkim73@samsung.com>
      Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Eric Van Hensbergen <ericvh@gmail.com>
      Cc: Takashi Iwai <tiwai@suse.de>
      Cc: Steven Whitehouse <swhiteho@redhat.com>
      Cc: Petr Vandrovec <petr@vandrovec.name>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: Avi Kivity <avi@redhat.com> 
      43829731
  9. 04 Aug, 2012 1 commit
  10. 22 Jul, 2012 6 commits
  11. 14 Jul, 2012 3 commits
  12. 06 May, 2012 1 commit
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  15. 04 Jan, 2012 4 commits
  16. 15 Nov, 2011 1 commit
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  21. 10 Mar, 2011 1 commit
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  24. 07 Jan, 2011 1 commit