tree fcc89671d4c8677a7689b6cf670708f164e79d36
parent fc19ad387e321c68d4fed011ed11ef1c303c650d
author Trond Myklebust <trond.myklebust@hammerspace.com> 1561632105 -0400
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1564904007 +0200

NFSv4: Handle the special Linux file open access mode

commit 44942b4e457beda00981f616402a1a791e8c616e upstream.

According to the open() manpage, Linux reserves the access mode 3
to mean "check for read and write permission on the file and return
a file descriptor that can't be used for reading or writing."

Currently, the NFSv4 code will ask the server to open the file,
and will use an incorrect share access mode of 0. Since it has
an incorrect share access mode, the client later forgets to send
a corresponding close, meaning it can leak stateids on the server.

Fixes: ce4ef7c0a8a05 ("NFS: Split out NFS v4 file operations")
Cc: stable@vger.kernel.org # 3.6+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>