svcrpc: fix potential GSSX_ACCEPT_SEC_CONTEXT decoding failures
svcrpc: fix potential GSSX_ACCEPT_SEC_CONTEXT decoding failures

In an environment where the KDC is running Active Directory, the
exported composite name field returned in the context could be large
enough to span a page boundary.  Attaching a scratch buffer to the
decoding xdr_stream helps deal with those cases.

The case where we saw this was actually due to behavior that's been
fixed in newer gss-proxy versions, but we're fixing it here too.

Signed-off-by: Scott Mayhew <129700617821125d23e4a9ae8bf609ed655da086@redhat.com>
Cc: 4fbacc2fa0ffdbb11bf1ad6925b886ebd08dd15f@vger.kernel.org
Reviewed-by: Simo Sorce <65f99581a93cf30dafc32b5c178edc6b0294a07f@redhat.com>
Signed-off-by: J. Bruce Fields <51738506c1b2ccb0761f23bdc612c93babf738ea@redhat.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs