[src/trunk]: src/lib/libc/rpc - limit size of buffers to RPC_MAXDATASIZE

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/31720b20bada
branches:  trunk
changeset: 823708:31720b20bada
user:      christos <christos%NetBSD.org@localhost>
date:      Wed May 03 21:39:27 2017 +0000

description:
- limit size of buffers to RPC_MAXDATASIZE
- don't leak memory
- be more picky about bad parameters
https://raw.githubusercontent.com/guidovranken/rpcbomb/master/libtirpc_patch.txt

XXX: pullup-7

diffstat:

 lib/libc/rpc/rpc_generic.c |  13 ++++++++++---
 lib/libc/rpc/rpcb_prot.c   |  26 ++++++++++++++++----------
 lib/libc/rpc/rpcb_st_xdr.c |  13 +++++++------
 lib/libc/rpc/xdr.c         |  34 +++++++++++++++++++++++++++-------
 4 files changed, 60 insertions(+), 26 deletions(-)

diffs (truncated from 309 to 300 lines):

diff -r 90bc51032cd4 -r 31720b20bada lib/libc/rpc/rpc_generic.c
--- a/lib/libc/rpc/rpc_generic.c        Wed May 03 21:36:16 2017 +0000
+++ b/lib/libc/rpc/rpc_generic.c        Wed May 03 21:39:27 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rpc_generic.c,v 1.29 2013/04/05 03:17:38 dholland Exp $        */
+/*     $NetBSD: rpc_generic.c,v 1.30 2017/05/03 21:39:27 christos Exp $        */
 
 /*
  * Copyright (c) 2010, Oracle America, Inc.
@@ -43,7 +43,7 @@
 
 #include <sys/cdefs.h>
 #if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: rpc_generic.c,v 1.29 2013/04/05 03:17:38 dholland Exp $");
+__RCSID("$NetBSD: rpc_generic.c,v 1.30 2017/05/03 21:39:27 christos Exp $");
 #endif
 
 #include "namespace.h"
@@ -644,6 +644,9 @@
 
        switch (af) {
        case AF_INET:
+               if (nbuf->len < sizeof(*sinp)) {
+                       return NULL;
+               }
                sinp = nbuf->buf;
                if (inet_ntop(af, &sinp->sin_addr, namebuf,
                    (socklen_t)sizeof namebuf) == NULL)
@@ -655,6 +658,9 @@
                break;
 #ifdef INET6
        case AF_INET6:
+               if (nbuf->len < sizeof(*sin6)) {
+                       return NULL;
+               }
                sin6 = nbuf->buf;
                if (inet_ntop(af, &sin6->sin6_addr, namebuf6,
                    (socklen_t)sizeof namebuf6) == NULL)
@@ -690,7 +696,8 @@
 #endif
        struct sockaddr_un *sun;
 
-       _DIAGASSERT(uaddr != NULL);
+       if (uaddr == NULL)
+               return NULL;
 
        addrstr = strdup(uaddr);
        if (addrstr == NULL)
diff -r 90bc51032cd4 -r 31720b20bada lib/libc/rpc/rpcb_prot.c
--- a/lib/libc/rpc/rpcb_prot.c  Wed May 03 21:36:16 2017 +0000
+++ b/lib/libc/rpc/rpcb_prot.c  Wed May 03 21:39:27 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rpcb_prot.c,v 1.11 2013/03/11 20:19:29 tron Exp $      */
+/*     $NetBSD: rpcb_prot.c,v 1.12 2017/05/03 21:39:27 christos Exp $  */
 
 /*
  * Copyright (c) 2010, Oracle America, Inc.
@@ -41,7 +41,7 @@
 #if 0
 static char sccsid[] = "@(#)rpcb_prot.c 1.9 89/04/21 Copyr 1984 Sun Micro";
 #else
-__RCSID("$NetBSD: rpcb_prot.c,v 1.11 2013/03/11 20:19:29 tron Exp $");
+__RCSID("$NetBSD: rpcb_prot.c,v 1.12 2017/05/03 21:39:27 christos Exp $");
 #endif
 #endif
 
@@ -58,6 +58,7 @@
 #include <rpc/types.h>
 #include <rpc/xdr.h>
 #include <rpc/rpcb_prot.h>
+#include <rpc/rpc_com.h>
 
 #include <assert.h>
 
@@ -85,13 +86,13 @@
        if (!xdr_u_int32_t(xdrs, &objp->r_vers)) {
                return (FALSE);
        }
-       if (!xdr_string(xdrs, &objp->r_netid, (u_int)~0)) {
+       if (!xdr_string(xdrs, &objp->r_netid, RPC_MAXDATASIZE)) {
                return (FALSE);
        }
-       if (!xdr_string(xdrs, &objp->r_addr, (u_int)~0)) {
+       if (!xdr_string(xdrs, &objp->r_addr, RPC_MAXDATASIZE)) {
                return (FALSE);
        }
-       if (!xdr_string(xdrs, &objp->r_owner, (u_int)~0)) {
+       if (!xdr_string(xdrs, &objp->r_owner, RPC_MAXDATASIZE)) {
                return (FALSE);
        }
        return (TRUE);
@@ -193,19 +194,19 @@
 
        _DIAGASSERT(objp != NULL);
 
-       if (!xdr_string(xdrs, &objp->r_maddr, (u_int)~0)) {
+       if (!xdr_string(xdrs, &objp->r_maddr, RPC_MAXDATASIZE)) {
                return (FALSE);
        }
-       if (!xdr_string(xdrs, &objp->r_nc_netid, (u_int)~0)) {
+       if (!xdr_string(xdrs, &objp->r_nc_netid, RPC_MAXDATASIZE)) {
                return (FALSE);
        }
        if (!xdr_u_int32_t(xdrs, &objp->r_nc_semantics)) {
                return (FALSE);
        }
-       if (!xdr_string(xdrs, &objp->r_nc_protofmly, (u_int)~0)) {
+       if (!xdr_string(xdrs, &objp->r_nc_protofmly, RPC_MAXDATASIZE)) {
                return (FALSE);
        }
-       if (!xdr_string(xdrs, &objp->r_nc_proto, (u_int)~0)) {
+       if (!xdr_string(xdrs, &objp->r_nc_proto, RPC_MAXDATASIZE)) {
                return (FALSE);
        }
        return (TRUE);
@@ -329,7 +330,7 @@
 
        _DIAGASSERT(p != NULL);
 
-       if (!xdr_string(xdrs, &objp->addr, (u_int)~0)) {
+       if (!xdr_string(xdrs, &objp->addr, RPC_MAXDATASIZE)) {
                return (FALSE);
        }
        if (!xdr_u_int(xdrs, &objp->results.results_len)) {
@@ -349,6 +350,11 @@
        if (!xdr_u_int32_t(xdrs, (u_int32_t *) &objp->maxlen)) {
                return (FALSE);
        }
+
+       if (objp->maxlen > RPC_MAXDATASIZE) {
+               return (FALSE);
+       }
+
        dummy = xdr_bytes(xdrs, (char **)(void *)&(objp->buf),
                        (u_int *)&(objp->len), objp->maxlen);
        return (dummy);
diff -r 90bc51032cd4 -r 31720b20bada lib/libc/rpc/rpcb_st_xdr.c
--- a/lib/libc/rpc/rpcb_st_xdr.c        Wed May 03 21:36:16 2017 +0000
+++ b/lib/libc/rpc/rpcb_st_xdr.c        Wed May 03 21:39:27 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rpcb_st_xdr.c,v 1.10 2013/03/11 20:19:29 tron Exp $    */
+/*     $NetBSD: rpcb_st_xdr.c,v 1.11 2017/05/03 21:39:27 christos Exp $        */
 
 /*
  * Copyright (c) 2010, Oracle America, Inc.
@@ -42,11 +42,12 @@
 
 #include <sys/cdefs.h>
 #if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: rpcb_st_xdr.c,v 1.10 2013/03/11 20:19:29 tron Exp $");
+__RCSID("$NetBSD: rpcb_st_xdr.c,v 1.11 2017/05/03 21:39:27 christos Exp $");
 #endif
 
 #include "namespace.h"
 #include <rpc/rpc.h>
+#include <rpc/rpc_com.h>
 
 #include <assert.h>
 
@@ -80,7 +81,7 @@
            if (!xdr_int(xdrs, &objp->failure)) {
                return (FALSE);
            }
-           if (!xdr_string(xdrs, &objp->netid, (u_int)~0)) {
+           if (!xdr_string(xdrs, &objp->netid, RPC_MAXDATASIZE)) {
                return (FALSE);
            }
 
@@ -132,7 +133,7 @@
                IXDR_PUT_INT32(buf, objp->failure);
                IXDR_PUT_INT32(buf, objp->indirect);
        }
-       if (!xdr_string(xdrs, &objp->netid, (u_int)~0)) {
+       if (!xdr_string(xdrs, &objp->netid, RPC_MAXDATASIZE)) {
                return (FALSE);
        }
        if (!xdr_pointer(xdrs, (char **)(void *)&objp->next,
@@ -170,7 +171,7 @@
                objp->failure = (int)IXDR_GET_INT32(buf);
                objp->indirect = (int)IXDR_GET_INT32(buf);
        }
-       if (!xdr_string(xdrs, &objp->netid, (u_int)~0)) {
+       if (!xdr_string(xdrs, &objp->netid, RPC_MAXDATASIZE)) {
                return (FALSE);
        }
        if (!xdr_pointer(xdrs, (char **)(void *)&objp->next,
@@ -198,7 +199,7 @@
        if (!xdr_int(xdrs, &objp->indirect)) {
                return (FALSE);
        }
-       if (!xdr_string(xdrs, &objp->netid, (u_int)~0)) {
+       if (!xdr_string(xdrs, &objp->netid, RPC_MAXDATASIZE)) {
                return (FALSE);
        }
        if (!xdr_pointer(xdrs, (char **)(void *)&objp->next,
diff -r 90bc51032cd4 -r 31720b20bada lib/libc/rpc/xdr.c
--- a/lib/libc/rpc/xdr.c        Wed May 03 21:36:16 2017 +0000
+++ b/lib/libc/rpc/xdr.c        Wed May 03 21:39:27 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: xdr.c,v 1.33 2013/03/11 20:19:29 tron Exp $    */
+/*     $NetBSD: xdr.c,v 1.34 2017/05/03 21:39:27 christos Exp $        */
 
 /*
  * Copyright (c) 2010, Oracle America, Inc.
@@ -37,7 +37,7 @@
 static char *sccsid = "@(#)xdr.c 1.35 87/08/12";
 static char *sccsid = "@(#)xdr.c       2.1 88/07/29 4.0 RPCSRC";
 #else
-__RCSID("$NetBSD: xdr.c,v 1.33 2013/03/11 20:19:29 tron Exp $");
+__RCSID("$NetBSD: xdr.c,v 1.34 2017/05/03 21:39:27 christos Exp $");
 #endif
 #endif
 
@@ -59,8 +59,10 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include <rpc/rpc.h>
 #include <rpc/types.h>
 #include <rpc/xdr.h>
+#include <rpc/rpc_com.h>
 
 #ifdef __weak_alias
 __weak_alias(xdr_bool,_xdr_bool)
@@ -98,7 +100,6 @@
  */
 #define XDR_FALSE      ((long) 0)
 #define XDR_TRUE       ((long) 1)
-#define LASTUNSIGNED   ((u_int) 0-1)
 
 /*
  * for unit alignment
@@ -590,6 +591,7 @@
 {
        char *sp;               /* sp is the actual string pointer */
        u_int nodesize;
+       bool_t ret, allocated = FALSE;
 
        _DIAGASSERT(xdrs != NULL);
        _DIAGASSERT(cpp != NULL);
@@ -619,6 +621,7 @@
                }
                if (sp == NULL) {
                        *cpp = sp = mem_alloc(nodesize);
+                       allocated = TRUE;
                }
                if (sp == NULL) {
                        warn("%s: out of memory", __func__);
@@ -627,7 +630,14 @@
                /* FALLTHROUGH */
 
        case XDR_ENCODE:
-               return (xdr_opaque(xdrs, sp, nodesize));
+               ret = xdr_opaque(xdrs, sp, nodesize);
+               if ((xdrs->x_op == XDR_DECODE) && (ret == FALSE)) {
+                       if (allocated == TRUE) {
+                               free(sp);
+                               *cpp = NULL;
+                       }
+               }
+               return (ret);
 
        case XDR_FREE:
                if (sp != NULL) {
@@ -727,6 +737,7 @@
        u_int size = 0;         /* XXX: GCC */
        u_int nodesize;
        size_t len;
+       bool_t ret, allocated = FALSE;
 
        _DIAGASSERT(xdrs != NULL);
        _DIAGASSERT(cpp != NULL);
@@ -767,8 +778,10 @@
                if (nodesize == 0) {
                        return (TRUE);
                }
-               if (sp == NULL)
+               if (sp == NULL) {
                        *cpp = sp = mem_alloc(nodesize);
+                       allocated = TRUE;
+               }
                if (sp == NULL) {
                        warn("%s: out of memory", __func__);
                        return (FALSE);
@@ -777,7 +790,14 @@
                /* FALLTHROUGH */
 
        case XDR_ENCODE:
-               return (xdr_opaque(xdrs, sp, size));
+               ret = xdr_opaque(xdrs, sp, size);
+               if ((xdrs->x_op == XDR_DECODE) && (ret == FALSE)) {
+                       if (allocated == TRUE) {
+                               free(sp);
+                               *cpp = NULL;
+                       }
+               }
+               return (ret);
 
        case XDR_FREE:
                mem_free(sp, nodesize);