[PATCH v1 06/25] SUNRPC: Convert svcauth_tls_accept() to use xdr_stream
From: Chuck Lever <cel@kernel.org>
Date: 2023-01-02 17:06:09
Subsystem:
kernel nfsd, sunrpc, and lockd servers, networking [general], nfs, sunrpc, and lockd clients, the rest · Maintainers:
Chuck Lever, Jeff Layton, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Trond Myklebust, Anna Schumaker, Linus Torvalds
From: Chuck Lever <chuck.lever@oracle.com> Done as part of hardening the server-side RPC header decoding path. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> --- net/sunrpc/svcauth_unix.c | 37 ++++++++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 11 deletions(-)
diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
index b6aef9c5113b..168e12137754 100644
--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c@@ -807,25 +807,41 @@ struct auth_ops svcauth_null = { }; +/** + * svcauth_tls_accept - Decode and validate incoming RPC_AUTH_TLS credential + * @rqstp: RPC transaction + * + * Return values: + * %SVC_OK: Both credential and verifier are valid + * %SVC_DENIED: Credential or verifier is not valid + * %SVC_GARBAGE: Failed to decode credential or verifier + * %SVC_CLOSE: Temporary failure + * + * rqstp->rq_auth_stat is set as mandated by RFC 5531. + */ static int svcauth_tls_accept(struct svc_rqst *rqstp) { + struct xdr_stream *xdr = &rqstp->rq_arg_stream; struct svc_cred *cred = &rqstp->rq_cred; - struct kvec *argv = rqstp->rq_arg.head; struct kvec *resv = rqstp->rq_res.head; + u32 flavor, len; + void *body; - if (argv->iov_len < XDR_UNIT * 3) - return SVC_GARBAGE; + svcxdr_init_decode(rqstp); - /* Call's cred length */ - if (svc_getu32(argv) != xdr_zero) { + /* Length of Call's credential body field: */ + if (xdr_stream_decode_u32(xdr, &len) < 0) + return SVC_GARBAGE; + if (len != 0) { rqstp->rq_auth_stat = rpc_autherr_badcred; return SVC_DENIED; } - /* Call's verifier flavor and its length */ - if (svc_getu32(argv) != rpc_auth_null || - svc_getu32(argv) != xdr_zero) { + /* Call's verf field: */ + if (xdr_stream_decode_opaque_auth(xdr, &flavor, &body, &len) < 0) + return SVC_GARBAGE; + if (flavor != RPC_AUTH_NULL || len != 0) { rqstp->rq_auth_stat = rpc_autherr_badverf; return SVC_DENIED; }
@@ -836,12 +852,12 @@ svcauth_tls_accept(struct svc_rqst *rqstp) return SVC_DENIED; } - /* Mapping to nobody uid/gid is required */ + /* Signal that mapping to nobody uid/gid is required */ cred->cr_uid = INVALID_UID; cred->cr_gid = INVALID_GID; cred->cr_group_info = groups_alloc(0); if (cred->cr_group_info == NULL) - return SVC_CLOSE; /* kmalloc failure - client must retry */ + return SVC_CLOSE; /* Reply's verifier */ svc_putnl(resv, RPC_AUTH_NULL);
@@ -853,7 +869,6 @@ svcauth_tls_accept(struct svc_rqst *rqstp) svc_putnl(resv, 0); rqstp->rq_cred.cr_flavor = RPC_AUTH_TLS; - svcxdr_init_decode(rqstp); return SVC_OK; }