sunrpc: Properly decode kuids and kgids in RPC_AUTH_UNIX credentials

When reading kuids from the wire map them into the initial user
namespace, and validate the mapping succeded.

When reading kgids from the wire map them into the initial user
namespace, and validate the mapping succeded.

Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
index bdea0a1..a1852e1 100644 (file)
--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c
@@ -821,8 +821,10 @@ svcauth_unix_accept(struct svc_rqst *rqstp, __be32 *authp)
        argv->iov_base = (void*)((__be32*)argv->iov_base + slen);       /* skip machname */
        argv->iov_len -= slen*4;
 
-       cred->cr_uid = svc_getnl(argv);         /* uid */
-       cred->cr_gid = svc_getnl(argv);         /* gid */
+       cred->cr_uid = make_kuid(&init_user_ns, svc_getnl(argv)); /* uid */
+       cred->cr_gid = make_kgid(&init_user_ns, svc_getnl(argv)); /* gid */
+       if (!uid_valid(cred->cr_uid) || !gid_valid(cred->cr_gid))
+               goto badcred;
        slen = svc_getnl(argv);                 /* gids length */
        if (slen > 16 || (len -= (slen + 2)*4) < 0)
                goto badcred;