Module Name: src
Committed By: maxv
Date: Mon Jan 15 07:59:48 UTC 2018
Modified Files:
src/sys/net: if_ethersubr.c
Log Message:
Fix the net.ether.multicast sysctl. If there is no multicast address
don't kmem_alloc(0) (which panics the kernel), and if the number of
multicast addresses has decreased don't copyout uninitialized kernel
data.
To generate a diff of this commit:
cvs rdiff -u -r1.250 -r1.251 src/sys/net/if_ethersubr.c
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/if_ethersubr.c
diff -u src/sys/net/if_ethersubr.c:1.250 src/sys/net/if_ethersubr.c:1.251
--- src/sys/net/if_ethersubr.c:1.250 Sat Dec 9 10:51:30 2017
+++ src/sys/net/if_ethersubr.c Mon Jan 15 07:59:48 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: if_ethersubr.c,v 1.250 2017/12/09 10:51:30 maxv Exp $ */
+/* $NetBSD: if_ethersubr.c,v 1.251 2018/01/15 07:59:48 maxv Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -61,7 +61,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_ethersubr.c,v 1.250 2017/12/09 10:51:30 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_ethersubr.c,v 1.251 2018/01/15 07:59:48 maxv Exp $");
#ifdef _KERNEL_OPT
#include "opt_inet.h"
@@ -1553,16 +1553,23 @@ ether_multicast_sysctl(SYSCTLFN_ARGS)
/*
* ec->ec_lock is a spin mutex so we cannot call sysctl_copyout, which
- * is sleepable, with holding it. Copy data to a local buffer first
- * with holding it and then call sysctl_copyout without holding it.
+ * is sleepable, while holding it. Copy data to a local buffer first
+ * with the lock taken and then call sysctl_copyout without holding it.
*/
retry:
multicnt = ec->ec_multicnt;
+
+ if (multicnt == 0) {
+ if_put(ifp, &psref);
+ *oldlenp = 0;
+ goto out;
+ }
+
addrs = kmem_alloc(sizeof(*addrs) * multicnt, KM_SLEEP);
ETHER_LOCK(ec);
- if (multicnt < ec->ec_multicnt) {
- /* The number of multicast addresses have increased */
+ if (multicnt != ec->ec_multicnt) {
+ /* The number of multicast addresses has changed */
ETHER_UNLOCK(ec);
kmem_free(addrs, sizeof(*addrs) * multicnt);
goto retry;
