1. 05 Dec, 2015 3 commits
    • Olga Kornievskaia's avatar
      Failing to send a CLOSE if file is opened WRONLY and server reboots on a 4.x mount · 88e77833
      Olga Kornievskaia authored
      commit a41cbe86 upstream.
      
      A test case is as the description says:
      open(foobar, O_WRONLY);
      sleep()  --> reboot the server
      close(foobar)
      
      The bug is because in nfs4state.c in nfs4_reclaim_open_state() a few
      line before going to restart, there is
      clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &state->flags).
      
      NFS4CLNT_RECLAIM_NOGRACE is a flag for the client states not open
      owner states. Value of NFS4CLNT_RECLAIM_NOGRACE is 4 which is the
      value of NFS_O_WRONLY_STATE in nfs4_state->flags. So clearing it wipes
      out state and when we go to close it, “call_close” doesn’t get set as
      state flag is not set and CLOSE doesn’t go on the wire.
      Signed-off-by: default avatarOlga Kornievskaia <aglo@umich.edu>
      Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      88e77833
    • Eric W. Biederman's avatar
      vfs: Test for and handle paths that are unreachable from their mnt_root · 44930ae4
      Eric W. Biederman authored
      commit 397d425d upstream.
      
      In rare cases a directory can be renamed out from under a bind mount.
      In those cases without special handling it becomes possible to walk up
      the directory tree to the root dentry of the filesystem and down
      from the root dentry to every other file or directory on the filesystem.
      
      Like division by zero .. from an unconnected path can not be given
      a useful semantic as there is no predicting at which path component
      the code will realize it is unconnected.  We certainly can not match
      the current behavior as the current behavior is a security hole.
      
      Therefore when encounting .. when following an unconnected path
      return -ENOENT.
      
      - Add a function path_connected to verify path->dentry is reachable
        from path->mnt.mnt_root.  AKA to validate that rename did not do
        something nasty to the bind mount.
      
        To avoid races path_connected must be called after following a path
        component to it's next path component.
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      44930ae4
    • Eric W. Biederman's avatar
      dcache: Handle escaped paths in prepend_path · fc9e08aa
      Eric W. Biederman authored
      commit cde93be4 upstream.
      
      A rename can result in a dentry that by walking up d_parent
      will never reach it's mnt_root.  For lack of a better term
      I call this an escaped path.
      
      prepend_path is called by four different functions __d_path,
      d_absolute_path, d_path, and getcwd.
      
      __d_path only wants to see paths are connected to the root it passes
      in.  So __d_path needs prepend_path to return an error.
      
      d_absolute_path similarly wants to see paths that are connected to
      some root.  Escaped paths are not connected to any mnt_root so
      d_absolute_path needs prepend_path to return an error greater
      than 1.  So escaped paths will be treated like paths on lazily
      unmounted mounts.
      
      getcwd needs to prepend "(unreachable)" so getcwd also needs
      prepend_path to return an error.
      
      d_path is the interesting hold out.  d_path just wants to print
      something, and does not care about the weird cases.  Which raises
      the question what should be printed?
      
      Given that <escaped_path>/<anything> should result in -ENOENT I
      believe it is desirable for escaped paths to be printed as empty
      paths.  As there are not really any meaninful path components when
      considered from the perspective of a mount tree.
      
      So tweak prepend_path to return an empty path with an new error
      code of 3 when it encounters an escaped path.
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      [bwh: For 2.6.32, implement the "(unreachable)" string in __d_path()]
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      fc9e08aa
  2. 18 Sep, 2015 37 commits