Module Name: src
Committed By: maxv
Date: Mon Jan 22 10:26:38 UTC 2018
Modified Files:
src/share/man/man9: mbuf.9
src/sys/kern: uipc_mbuf.c
Log Message:
m_prepend does not tolerate being given len > MHLEN, so add a panic, and
document this behavior.
To generate a diff of this commit:
cvs rdiff -u -r1.53 -r1.54 src/share/man/man9/mbuf.9
cvs rdiff -u -r1.179 -r1.180 src/sys/kern/uipc_mbuf.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/share/man/man9/mbuf.9
diff -u src/share/man/man9/mbuf.9:1.53 src/share/man/man9/mbuf.9:1.54
--- src/share/man/man9/mbuf.9:1.53 Mon Jan 1 12:46:49 2018
+++ src/share/man/man9/mbuf.9 Mon Jan 22 10:26:38 2018
@@ -1,4 +1,4 @@
-.\" $NetBSD: mbuf.9,v 1.53 2018/01/01 12:46:49 wiz Exp $
+.\" $NetBSD: mbuf.9,v 1.54 2018/01/22 10:26:38 maxv Exp $
.\"
.\" Copyright (c) 1997 The NetBSD Foundation, Inc.
.\" All rights reserved.
@@ -27,7 +27,7 @@
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
-.Dd January 1, 2018
+.Dd January 22, 2018
.Dt MBUF 9
.Os
.Sh NAME
@@ -431,6 +431,10 @@ The
parameter is a choice of
.Dv M_WAIT / M_DONTWAIT
from caller.
+It is illegal for the
+.Fa len
+parameter to be greater than
+.Dv MHLEN .
.It Fn m_pulldown "struct mbuf *m" "int off" "int len" "int *offp"
Rearranges an mbuf chain so that
.Fa len
Index: src/sys/kern/uipc_mbuf.c
diff -u src/sys/kern/uipc_mbuf.c:1.179 src/sys/kern/uipc_mbuf.c:1.180
--- src/sys/kern/uipc_mbuf.c:1.179 Mon Jan 22 09:06:40 2018
+++ src/sys/kern/uipc_mbuf.c Mon Jan 22 10:26:38 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: uipc_mbuf.c,v 1.179 2018/01/22 09:06:40 maxv Exp $ */
+/* $NetBSD: uipc_mbuf.c,v 1.180 2018/01/22 10:26:38 maxv Exp $ */
/*
* Copyright (c) 1999, 2001 The NetBSD Foundation, Inc.
@@ -62,7 +62,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uipc_mbuf.c,v 1.179 2018/01/22 09:06:40 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uipc_mbuf.c,v 1.180 2018/01/22 10:26:38 maxv Exp $");
#ifdef _KERNEL_OPT
#include "opt_mbuftrace.h"
@@ -661,6 +661,10 @@ m_prepend(struct mbuf *m, int len, int h
{
struct mbuf *mn;
+ if (__predict_false(len > MHLEN)) {
+ panic("%s: len > MHLEN", __func__);
+ }
+
KASSERT(len != M_COPYALL);
mn = m_get(how, m->m_type);
if (mn == NULL) {
