90bfc37b5a
Ensure that stream-based argument decoding can't go past the actual
end of the receive buffer. xdr_init_decode's calculation of the
value of xdr->end over-estimates the end of the buffer because the
Linux kernel RPC server code does not remove the size of the RPC
header from rqstp->rq_arg before calling the upper layer's
dispatcher.
The server-side still uses the svc_getnl() macros to decode the
RPC call header. These macros reduce the length of the head iov
but do not update the total length of the message in the buffer
(buf->len).
A proper fix for this would be to replace the use of svc_getnl() and
friends in the RPC header decoder, but that would be a large and
invasive change that would be difficult to backport.
Fixes: 5191955d6fc6 ("SUNRPC: Prepare for xdr_stream-style decoding on the server-side")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
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.