[src/trunk]: src/sys/net wg: KASSERT m_len before mtod.

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

details:   https://anonhg.NetBSD.org/src/rev/6bb694577c7a
branches:  trunk
changeset: 975329:6bb694577c7a
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Thu Aug 27 02:54:31 2020 +0000

description:
wg: KASSERT m_len before mtod.

XXX We should really make mtod do this automagically, and use
something else for mtod(m, void *).

diffstat:

 sys/net/if_wg.c |  12 +++++++++---
 1 files changed, 9 insertions(+), 3 deletions(-)

diffs (66 lines):

diff -r 056711a69b7b -r 6bb694577c7a sys/net/if_wg.c
--- a/sys/net/if_wg.c   Thu Aug 27 02:53:47 2020 +0000
+++ b/sys/net/if_wg.c   Thu Aug 27 02:54:31 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_wg.c,v 1.26 2020/08/27 02:53:47 riastradh Exp $     */
+/*     $NetBSD: if_wg.c,v 1.27 2020/08/27 02:54:31 riastradh Exp $     */
 
 /*
  * Copyright (C) Ryota Ozaki <ozaki.ryota%gmail.com@localhost>
@@ -41,7 +41,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_wg.c,v 1.26 2020/08/27 02:53:47 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_wg.c,v 1.27 2020/08/27 02:54:31 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -1570,7 +1570,6 @@
        m = m_gethdr(M_WAIT, MT_DATA);
        m->m_pkthdr.len = m->m_len = sizeof(*wgmi);
        wgmi = mtod(m, struct wg_msg_init *);
-
        wg_fill_msg_init(wg, wgp, wgs, wgmi);
 
        error = wg->wg_ops->send_hs_msg(wgp, m);
@@ -2387,6 +2386,7 @@
                free_encrypted_buf = true;
        }
        /* m_ensure_contig may change m regardless of its result */
+       KASSERT(m->m_len >= sizeof(*wgmd));
        wgmd = mtod(m, struct wg_msg_data *);
 
        decrypted_len = encrypted_len - WG_AUTHTAG_LEN;
@@ -2683,6 +2683,7 @@
                }
 
                KASSERT(paddr != NULL);
+               KASSERT(paddr->m_len >= sizeof(struct sockaddr));
                src = mtod(paddr, struct sockaddr *);
 
                wg_handle_packet(wg, m, src);
@@ -3683,6 +3684,7 @@
                error = ENOBUFS;
                goto end;
        }
+       KASSERT(n->m_len >= sizeof(*wgmd));
        wgmd = mtod(n, struct wg_msg_data *);
        wg_fill_msg_data(wg, wgp, wgs, wgmd);
        /* [W] 5.4.6: AEAD(Tm^send, Nm^send, P, e) */
@@ -4553,11 +4555,15 @@
        if (af == AF_INET) {
                struct sockaddr_in *sin = (struct sockaddr_in *)&ss;
                struct ip *ip;
+
+               KASSERT(m->m_len >= sizeof(struct ip));
                ip = mtod(m, struct ip *);
                sockaddr_in_init(sin, &ip->ip_dst, 0);
        } else {
                struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&ss;
                struct ip6_hdr *ip6;
+
+               KASSERT(m->m_len >= sizeof(struct ip6_hdr));
                ip6 = mtod(m, struct ip6_hdr *);
                sockaddr_in6_init(sin6, &ip6->ip6_dst, 0, 0, 0);
        }