[ 074/103] svcrpc: fix failures to handle -1 uids

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

3.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: "J. Bruce Fields" <bfields@redhat.com>

commit 0979292bfa301cb87d936b69af428090d2feea1b upstream.

As of f025adf191924e3a75ce80e130afcd2485b53bb8 "sunrpc: Properly decode
kuids and kgids in RPC_AUTH_UNIX credentials" any rpc containing a -1
(0xffff) uid or gid would fail with a badcred error.

Commit afe3c3fd5392b2f0066930abc5dbd3f4b14a0f13 "svcrpc: fix failures to
handle -1 uid's and gid's" fixed part of the problem, but overlooked the
gid upcall--the kernel can request supplementary gid's for the -1 uid,
but mountd's attempt write a response will get -EINVAL.

Symptoms were nfsd failing to reply to the first attempt to use a newly
negotiated krb5 context.

Reported-by: Sven Geggus <lists@fuchsschwanzdomain.de>
Tested-by: Sven Geggus <lists@fuchsschwanzdomain.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/sunrpc/svcauth_unix.c |    2 --
 1 file changed, 2 deletions(-)

--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c
@@ -493,8 +493,6 @@ static int unix_gid_parse(struct cache_d
 	if (rv)
 		return -EINVAL;
 	uid = make_kuid(&init_user_ns, id);
-	if (!uid_valid(uid))
-		return -EINVAL;
 	ug.uid = uid;
 
 	expiry = get_expiry(&mesg);