[IPV4/IPV6] multicast: Check add_grhead() return value
add_grhead() allocates memory with GFP_ATOMIC and in at least two places skb
from it passed to skb_put() without checking.
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 882cde4..e3ec216 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1582,6 +1582,8 @@
skb = add_grhead(skb, pmc, type, &pgr);
first = 0;
}
+ if (!skb)
+ return NULL;
psrc = (struct in6_addr *)skb_put(skb, sizeof(*psrc));
*psrc = psf->sf_addr;
scount++; stotal++;