Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3d91c1a8 authored by Patrick McHardy's avatar Patrick McHardy
Browse files

IPVS: fix potential stack overflow with overly long protocol names 



When protocols use very long names, the sprintf calls might overflow
the on-stack buffer. No protocol in the kernel does this however.

Print the protocol name in the pr_debug statement directly to avoid
this.

Based on patch by Zhitong Wang <zhitong.wangzt@alibaba-inc.com>
Acked-by: default avatarSimon Horman <horms@verge.net.au>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent 02e4eb75

net/netfilter/ipvs/ip_vs_proto.c

+12 −16
Original line number Diff line number Diff line
@@ -166,26 +166,24 @@ ip_vs_tcpudp_debug_packet_v4(struct ip_vs_protocol *pp, 


	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);

	if (ih == NULL)

		sprintf(buf, "%s TRUNCATED", pp->name);

		sprintf(buf, "TRUNCATED");

	else if (ih->frag_off & htons(IP_OFFSET))

		sprintf(buf, "%s %pI4->%pI4 frag",

			pp->name, &ih->saddr, &ih->daddr);

		sprintf(buf, "%pI4->%pI4 frag", &ih->saddr, &ih->daddr);

	else {

		__be16 _ports[2], *pptr

;

		pptr = skb_header_pointer(skb, offset + ih->ihl*4,

					  sizeof(_ports), _ports);

		if (pptr == NULL)

			sprintf(buf, "%s TRUNCATED %pI4->%pI4",

				pp->name, &ih->saddr, &ih->daddr);

			sprintf(buf, "TRUNCATED %pI4->%pI4",

				&ih->saddr, &ih->daddr);

		else

			sprintf(buf, "%s %pI4:%u->%pI4:%u",

				pp->name,

			sprintf(buf, "%pI4:%u->%pI4:%u",

				&ih->saddr, ntohs(pptr[0]),

				&ih->daddr, ntohs(pptr[1]));

	}



	pr_debug("%s: %s\n", msg, buf);

	pr_debug("%s: %s %s\n", msg, pp->name, buf);

}



#ifdef CONFIG_IP_VS_IPV6
@@ -200,26 +198,24 @@ ip_vs_tcpudp_debug_packet_v6(struct ip_vs_protocol *pp, 


	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);

	if (ih == NULL)

		sprintf(buf, "%s TRUNCATED", pp->name);

		sprintf(buf, "TRUNCATED");

	else if (ih->nexthdr == IPPROTO_FRAGMENT)

		sprintf(buf, "%s %pI6->%pI6 frag",

			pp->name, &ih->saddr, &ih->daddr);

		sprintf(buf, "%pI6->%pI6 frag",	&ih->saddr, &ih->daddr);

	else {

		__be16 _ports[2], *pptr;



		pptr = skb_header_pointer(skb, offset + sizeof(struct ipv6hdr),

					  sizeof(_ports), _ports);

		if (pptr == NULL)

			sprintf(buf, "%s TRUNCATED %pI6->%pI6",

				pp->name, &ih->saddr, &ih->daddr);

			sprintf(buf, "TRUNCATED %pI6->%pI6",

				&ih->saddr, &ih->daddr);

		else

			sprintf(buf, "%s %pI6:%u->%pI6:%u",

				pp->name,

			sprintf(buf, "%pI6:%u->%pI6:%u",

				&ih->saddr, ntohs(pptr[0]),

				&ih->daddr, ntohs(pptr[1]));

	}



	pr_debug("%s: %s\n", msg, buf);

	pr_debug("%s: %s %s\n", msg, pp->name, buf);

}

#endif

net/netfilter/ipvs/ip_vs_proto_ah_esp.c

+6 −8
Original line number Diff line number Diff line
@@ -136,12 +136,11 @@ ah_esp_debug_packet_v4(struct ip_vs_protocol *pp, const struct sk_buff *skb, 


	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);

	if (ih == NULL)

		sprintf(buf, "%s TRUNCATED", pp->name);

		sprintf(buf, "TRUNCATED");

	else

		sprintf(buf, "%s %pI4->%pI4",

			pp->name, &ih->saddr, &ih->daddr);

		sprintf(buf, "%pI4->%pI4", &ih->saddr, &ih->daddr);



	pr_debug("%s: %s\n", msg, buf);

	pr_debug("%s: %s %s\n", msg, pp->name, buf);

}



#ifdef CONFIG_IP_VS_IPV6
@@ -154,12 +153,11 @@ ah_esp_debug_packet_v6(struct ip_vs_protocol *pp, const struct sk_buff *skb, 


	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);

	if (ih == NULL)

		sprintf(buf, "%s TRUNCATED", pp->name);

		sprintf(buf, "TRUNCATED");

	else

		sprintf(buf, "%s %pI6->%pI6",

			pp->name, &ih->saddr, &ih->daddr);

		sprintf(buf, "%pI6->%pI6", &ih->saddr, &ih->daddr);



	pr_debug("%s: %s\n", msg, buf);

	pr_debug("%s: %s %s\n", msg, pp->name, buf);

}

#endif