Module Name: src
Committed By: riastradh
Date: Sun Jun 26 17:55:24 UTC 2022
Modified Files:
src/sys/net/lagg: if_lagg.c if_laggproto.h
Log Message:
lagg(4): Safely handle misaligned mbufs.
Optimizing for non-strict-alignment architectures -- without falling
afoul of alignment sanitizers or overeager compilers -- is left as an
exercise for the reader.
PR kern/56894
To generate a diff of this commit:
cvs rdiff -u -r1.47 -r1.48 src/sys/net/lagg/if_lagg.c
cvs rdiff -u -r1.17 -r1.18 src/sys/net/lagg/if_laggproto.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/net/lagg/if_lagg.c
diff -u src/sys/net/lagg/if_lagg.c:1.47 src/sys/net/lagg/if_lagg.c:1.48
--- src/sys/net/lagg/if_lagg.c:1.47 Mon Apr 4 09:59:41 2022
+++ src/sys/net/lagg/if_lagg.c Sun Jun 26 17:55:24 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: if_lagg.c,v 1.47 2022/04/04 09:59:41 martin Exp $ */
+/* $NetBSD: if_lagg.c,v 1.48 2022/06/26 17:55:24 riastradh Exp $ */
/*
* Copyright (c) 2005, 2006 Reyk Floeter <r...@openbsd.org>
@@ -20,7 +20,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_lagg.c,v 1.47 2022/04/04 09:59:41 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_lagg.c,v 1.48 2022/06/26 17:55:24 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_inet.h"
@@ -895,7 +895,7 @@ lagg_hashmbuf(struct lagg_softc *sc, str
*(hp) = hash32_buf(&(v), sizeof(v), *(hp)); \
} while(0)
- eh = lagg_m_extract(m, 0, sizeof(*eh), &buf);
+ eh = lagg_m_extract(m, 0, sizeof(*eh), __alignof(*eh), &buf);
if (eh == NULL)
goto out;
@@ -903,7 +903,8 @@ lagg_hashmbuf(struct lagg_softc *sc, str
etype = ntohs(eh->ether_type);
if (etype == ETHERTYPE_VLAN) {
- evl = lagg_m_extract(m, 0, sizeof(*evl), &buf);
+ evl = lagg_m_extract(m, 0, sizeof(*evl), __alignof(*evl),
+ &buf);
if (evl == NULL)
goto out;
@@ -924,7 +925,7 @@ lagg_hashmbuf(struct lagg_softc *sc, str
switch (etype) {
case ETHERTYPE_IP:
- ip = lagg_m_extract(m, off, sizeof(*ip), &buf);
+ ip = lagg_m_extract(m, off, sizeof(*ip), __alignof(*ip), &buf);
if (ip == NULL)
goto out;
@@ -937,7 +938,8 @@ lagg_hashmbuf(struct lagg_softc *sc, str
proto = ip->ip_p;
break;
case ETHERTYPE_IPV6:
- ip6 = lagg_m_extract(m, off, sizeof(*ip6), &buf);
+ ip6 = lagg_m_extract(m, off, sizeof(*ip6), __alignof(*ip6),
+ &buf);
if (ip6 == NULL)
goto out;
@@ -957,7 +959,7 @@ lagg_hashmbuf(struct lagg_softc *sc, str
switch (proto) {
case IPPROTO_TCP:
- th = lagg_m_extract(m, off, sizeof(*th), &buf);
+ th = lagg_m_extract(m, off, sizeof(*th), __alignof(*th), &buf);
if (th == NULL)
goto out;
@@ -967,7 +969,7 @@ lagg_hashmbuf(struct lagg_softc *sc, str
}
break;
case IPPROTO_UDP:
- uh = lagg_m_extract(m, off, sizeof(*uh), &buf);
+ uh = lagg_m_extract(m, off, sizeof(*uh), __alignof(*uh), &buf);
if (uh == NULL)
goto out;
Index: src/sys/net/lagg/if_laggproto.h
diff -u src/sys/net/lagg/if_laggproto.h:1.17 src/sys/net/lagg/if_laggproto.h:1.18
--- src/sys/net/lagg/if_laggproto.h:1.17 Tue May 24 20:50:20 2022
+++ src/sys/net/lagg/if_laggproto.h Sun Jun 26 17:55:24 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: if_laggproto.h,v 1.17 2022/05/24 20:50:20 andvar Exp $ */
+/* $NetBSD: if_laggproto.h,v 1.18 2022/06/26 17:55:24 riastradh Exp $ */
/*
* Copyright (c) 2021 Internet Initiative Japan Inc.
@@ -217,7 +217,8 @@ struct lagg_softc {
(_lp)->lp_ioctl((_lp)->lp_ifp, (_cmd), (_data))
static inline const void *
-lagg_m_extract(struct mbuf *m, size_t off, size_t reqlen, void *buf)
+lagg_m_extract(struct mbuf *m, size_t off, size_t reqlen, size_t align,
+ void *buf)
{
ssize_t len;
const void *rv;
@@ -229,7 +230,8 @@ lagg_m_extract(struct mbuf *m, size_t of
return NULL;
}
- if (m->m_len >= len) {
+ if (m->m_len >= len &&
+ ((uintptr_t)(mtod(m, uint8_t *) + off) % align) == 0) {
rv = mtod(m, uint8_t *) + off;
} else {
m_copydata(m, off, reqlen, buf);
