1. 12 Sep, 2013 1 commit
  2. 11 Sep, 2013 1 commit
  3. 29 Jun, 2013 2 commits
  4. 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
  5. 28 Feb, 2013 1 commit
    • Sasha Levin's avatar
      hlist: drop the node parameter from iterators · b67bfe0d
      Sasha Levin authored
      I'm not sure why, but the hlist for each entry iterators were conceived
      
              list_for_each_entry(pos, head, member)
      
      The hlist ones were greedy and wanted an extra parameter:
      
              hlist_for_each_entry(tpos, pos, head, member)
      
      Why did they need an extra pos parameter? I'm not quite sure. Not only
      they don't really need it, it also prevents the iterator from looking
      exactly like the list iterator, which is unfortunate.
      
      Besides the semantic patch, there was some manual work required:
      
       - Fix up the actual hlist iterators in linux/list.h
       - Fix up the declaration of other iterators based on the hlist ones.
       - A very small amount of places were using the 'node' parameter, this
       was modified to use 'obj->member' instead.
       - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
       properly, so those had to be fixed up manually.
      
      The semantic patch which is mostly the work of Peter Senna Tschudin is here:
      
      @@
      iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;
      
      type T;
      expression a,c,d,e;
      identifier b;
      statement S;
      @@
      
      -T b;
          <+... when != b
      (
      hlist_for_each_entry(a,
      - b,
      c, d) S
      |
      hlist_for_each_entry_continue(a,
      - b,
      c) S
      |
      hlist_for_each_entry_from(a,
      - b,
      c) S
      |
      hlist_for_each_entry_rcu(a,
      - b,
      c, d) S
      |
      hlist_for_each_entry_rcu_bh(a,
      - b,
      c, d) S
      |
      hlist_for_each_entry_continue_rcu_bh(a,
      - b,
      c) S
      |
      for_each_busy_worker(a, c,
      - b,
      d) S
      |
      ax25_uid_for_each(a,
      - b,
      c) S
      |
      ax25_for_each(a,
      - b,
      c) S
      |
      inet_bind_bucket_for_each(a,
      - b,
      c) S
      |
      sctp_for_each_hentry(a,
      - b,
      c) S
      |
      sk_for_each(a,
      - b,
      c) S
      |
      sk_for_each_rcu(a,
      - b,
      c) S
      |
      sk_for_each_from
      -(a, b)
      +(a)
      S
      + sk_for_each_from(a) S
      |
      sk_for_each_safe(a,
      - b,
      c, d) S
      |
      sk_for_each_bound(a,
      - b,
      c) S
      |
      hlist_for_each_entry_safe(a,
      - b,
      c, d, e) S
      |
      hlist_for_each_entry_continue_rcu(a,
      - b,
      c) S
      |
      nr_neigh_for_each(a,
      - b,
      c) S
      |
      nr_neigh_for_each_safe(a,
      - b,
      c, d) S
      |
      nr_node_for_each(a,
      - b,
      c) S
      |
      nr_node_for_each_safe(a,
      - b,
      c, d) S
      |
      - for_each_gfn_sp(a, c, d, b) S
      + for_each_gfn_sp(a, c, d) S
      |
      - for_each_gfn_indirect_valid_sp(a, c, d, b) S
      + for_each_gfn_indirect_valid_sp(a, c, d) S
      |
      for_each_host(a,
      - b,
      c) S
      |
      for_each_host_safe(a,
      - b,
      c, d) S
      |
      for_each_mesh_entry(a,
      - b,
      c, d) S
      )
          ...+>
      
      [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
      [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
      [akpm@linux-foundation.org: checkpatch fixes]
      [akpm@linux-foundation.org: fix warnings]
      [akpm@linux-foudnation.org: redo intrusive kvm changes]
      Tested-by: default avatarPeter Senna Tschudin <peter.senna@gmail.com>
      Acked-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      Cc: Wu Fengguang <fengguang.wu@intel.com>
      Cc: Marcelo Tosatti <mtosatti@redhat.com>
      Cc: Gleb Natapov <gleb@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b67bfe0d
  6. 23 Feb, 2013 1 commit
  7. 21 Jan, 2013 1 commit
  8. 20 Dec, 2012 1 commit
  9. 03 Oct, 2012 1 commit
  10. 21 Sep, 2012 1 commit
  11. 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
  12. 31 Jul, 2012 1 commit
  13. 14 Jul, 2012 12 commits
  14. 30 May, 2012 1 commit
  15. 06 May, 2012 1 commit
  16. 21 Mar, 2012 1 commit
  17. 04 Jan, 2012 4 commits
  18. 02 Nov, 2011 2 commits
  19. 21 Jul, 2011 1 commit
    • Josef Bacik's avatar
      fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers · 02c24a82
      Josef Bacik authored
      Btrfs needs to be able to control how filemap_write_and_wait_range() is called
      in fsync to make it less of a painful operation, so push down taking i_mutex and
      the calling of filemap_write_and_wait() down into the ->fsync() handlers.  Some
      file systems can drop taking the i_mutex altogether it seems, like ext3 and
      ocfs2.  For correctness sake I just pushed everything down in all cases to make
      sure that we keep the current behavior the same for everybody, and then each
      individual fs maintainer can make up their mind about what to do from there.
      Thanks,
      Acked-by: default avatarJan Kara <jack@suse.cz>
      Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      02c24a82
  20. 28 May, 2011 1 commit
  21. 26 May, 2011 2 commits
  22. 17 Mar, 2011 1 commit
  23. 10 Mar, 2011 1 commit