From 893deac4c43b57ae49f736ec050724b6de181062 Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Thu, 24 Aug 2017 11:41:31 +0200 Subject: [PATCH] lib/libnetlink: Don't pass NULL parameter to memcpy() Both addattr_l() and rta_addattr_l() may be called with NULL data pointer and 0 alen parameters. Avoid calling memcpy() in that case. Signed-off-by: Phil Sutter --- lib/libnetlink.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/lib/libnetlink.c b/lib/libnetlink.c index 00c853779..be7ac8658 100644 --- a/lib/libnetlink.c +++ b/lib/libnetlink.c @@ -870,7 +870,8 @@ int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data, rta = NLMSG_TAIL(n); rta->rta_type = type; rta->rta_len = len; - memcpy(RTA_DATA(rta), data, alen); + if (alen) + memcpy(RTA_DATA(rta), data, alen); n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len); return 0; } @@ -957,7 +958,8 @@ int rta_addattr_l(struct rtattr *rta, int maxlen, int type, subrta = (struct rtattr *)(((char *)rta) + RTA_ALIGN(rta->rta_len)); subrta->rta_type = type; subrta->rta_len = len; - memcpy(RTA_DATA(subrta), data, alen); + if (alen) + memcpy(RTA_DATA(subrta), data, alen); rta->rta_len = NLMSG_ALIGN(rta->rta_len) + RTA_ALIGN(len); return 0; } -- 2.47.2