Commit 906cce04 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'net-sched-ife-malformed-ife-packet-fixes' 



Alexander Aring says:

====================
net: sched: ife: malformed ife packet fixes

As promised at netdev 2.2 tc workshop I am working on adding scapy support for
tdc testing. It is still work in progress. I will submit the patches to tdc
later (they are not in good shape yet). The good news is I have been able to
find bugs which normal packet testing would not be able to find.
With fuzzy testing I was able to craft certain malformed packets that IFE
action was not able to deal with. This patch set fixes those bugs.

changes since v4:
 - use pskb_may_pull before pointer assign

changes since v3:
 - use pskb_may_pull

changes since v2:
 - remove inline from __ife_tlv_meta_valid
 - add const to cast to meta_tlvhdr
 - add acked and reviewed tags
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 7c5aba21 d57493d6

include/net/ife.h

+2 −1
Original line number Diff line number Diff line
@@ -12,7 +12,8 @@ 
void *ife_encode(struct sk_buff *skb, u16 metalen);

void *ife_decode(struct sk_buff *skb, u16 *metalen);



void *ife_tlv_meta_decode(void *skbdata, u16 *attrtype, u16 *dlen, u16 *totlen);

void *ife_tlv_meta_decode(void *skbdata, const void *ifehdr_end, u16 *attrtype,

			  u16 *dlen, u16 *totlen);

int ife_tlv_meta_encode(void *skbdata, u16 attrtype, u16 dlen,

			const void *dval);

net/ife/ife.c

+36 −2
Original line number Diff line number Diff line
@@ -69,6 +69,9 @@ void *ife_decode(struct sk_buff *skb, u16 *metalen) 
	int total_pull;

	u16 ifehdrln;



	if (!pskb_may_pull(skb, skb->dev->hard_header_len + IFE_METAHDRLEN))

		return NULL;



	ifehdr = (struct ifeheadr *) (skb->data + skb->dev->hard_header_len);

	ifehdrln = ntohs(ifehdr->metalen);

	total_pull = skb->dev->hard_header_len + ifehdrln;
@@ -92,12 +95,43 @@ struct meta_tlvhdr { 
	__be16 len;

};



static bool __ife_tlv_meta_valid(const unsigned char *skbdata,

				 const unsigned char *ifehdr_end)

{

	const struct meta_tlvhdr *tlv;

	u16 tlvlen;



	if (unlikely(skbdata + sizeof(*tlv) > ifehdr_end))

		return false;



	tlv = (const struct meta_tlvhdr *)skbdata;

	tlvlen = ntohs(tlv->len);



	/* tlv length field is inc header, check on minimum */

	if (tlvlen < NLA_HDRLEN)

		return false;



	/* overflow by NLA_ALIGN check */

	if (NLA_ALIGN(tlvlen) < tlvlen)

		return false;



	if (unlikely(skbdata + NLA_ALIGN(tlvlen) > ifehdr_end))

		return false;



	return true;

}



/* Caller takes care of presenting data in network order

 */

void *ife_tlv_meta_decode(void *skbdata, u16 *attrtype, u16 *dlen, u16 *totlen)

void *ife_tlv_meta_decode(void *skbdata, const void *ifehdr_end, u16 *attrtype,

			  u16 *dlen, u16 *totlen)

{

	struct meta_tlvhdr *tlv = (struct meta_tlvhdr *) skbdata;

	struct meta_tlvhdr *tlv;



	if (!__ife_tlv_meta_valid(skbdata, ifehdr_end))

		return NULL;



	tlv = (struct meta_tlvhdr *)skbdata;

	*dlen = ntohs(tlv->len) - NLA_HDRLEN;

	*attrtype = ntohs(tlv->type);

net/sched/act_ife.c

+7 −2
Original line number Diff line number Diff line
@@ -652,7 +652,7 @@ static int find_decode_metaid(struct sk_buff *skb, struct tcf_ife_info *ife, 
		}

	}



	return 0;

	return -ENOENT;

}



static int tcf_ife_decode(struct sk_buff *skb, const struct tc_action *a,
@@ -682,7 +682,12 @@ static int tcf_ife_decode(struct sk_buff *skb, const struct tc_action *a, 
		u16 mtype;

		u16 dlen;



		curr_data = ife_tlv_meta_decode(tlv_data, &mtype, &dlen, NULL);

		curr_data = ife_tlv_meta_decode(tlv_data, ifehdr_end, &mtype,

						&dlen, NULL);

		if (!curr_data) {

			qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));

			return TC_ACT_SHOT;

		}



		if (find_decode_metaid(skb, ife, mtype, dlen, curr_data)) {

			/* abuse overlimits to count when we receive metadata

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