J. Bruce Fields ff371bc83b nfsd4: catch some false session retries
commit 53da6a53e1d414e05759fa59b7032ee08f4e22d7 upstream.

The spec allows us to return NFS4ERR_SEQ_FALSE_RETRY if we notice that
the client is making a call that matches a previous (slot, seqid) pair
but that *isn't* actually a replay, because some detail of the call
doesn't actually match the previous one.

Catching every such case is difficult, but we may as well catch a few
easy ones.  This also handles the case described in the previous patch,
in a different way.

The spec does however require us to catch the case where the difference
is in the rpc credentials.  This prevents somebody from snooping another
user's replies by fabricating retries.

(But the practical value of the attack is limited by the fact that the
replies with the most sensitive data are READ replies, which are not
normally cached.)

Tested-by: Olga Kornievskaia <aglo@umich.edu>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Donald Buczek <buczek@molgen.mpg.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12 19:46:14 +01:00
2019-02-06 17:31:37 +01:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
No description provided
Readme 1.4 GiB
Languages
C 98.1%
Assembly 1.2%
Makefile 0.3%