Commit 6d65561f authored by Kangjie Lu's avatar Kangjie Lu Committed by Pablo Neira Ayuso
Browse files

netfilter: ip6t_srh: fix NULL pointer dereferences 



skb_header_pointer may return NULL. The current code dereference
its return values without a NULL check.

The fix inserts the checks to avoid NULL pointer dereferences.

Fixes: 202a8ff5 ("netfilter: add IPv6 segment routing header 'srh' match")
Signed-off-by: default avatarKangjie Lu <kjlu@umn.edu>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent d1fa3810

net/ipv6/netfilter/ip6t_srh.c

+6 −0
Original line number Diff line number Diff line
@@ -210,6 +210,8 @@ static bool srh1_mt6(const struct sk_buff *skb, struct xt_action_param *par) 
		psidoff = srhoff + sizeof(struct ipv6_sr_hdr) +

			  ((srh->segments_left + 1) * sizeof(struct in6_addr));

		psid = skb_header_pointer(skb, psidoff, sizeof(_psid), &_psid);

		if (!psid)

			return false;

		if (NF_SRH_INVF(srhinfo, IP6T_SRH_INV_PSID,

				ipv6_masked_addr_cmp(psid, &srhinfo->psid_msk,

						     &srhinfo->psid_addr)))
@@ -223,6 +225,8 @@ static bool srh1_mt6(const struct sk_buff *skb, struct xt_action_param *par) 
		nsidoff = srhoff + sizeof(struct ipv6_sr_hdr) +

			  ((srh->segments_left - 1) * sizeof(struct in6_addr));

		nsid = skb_header_pointer(skb, nsidoff, sizeof(_nsid), &_nsid);

		if (!nsid)

			return false;

		if (NF_SRH_INVF(srhinfo, IP6T_SRH_INV_NSID,

				ipv6_masked_addr_cmp(nsid, &srhinfo->nsid_msk,

						     &srhinfo->nsid_addr)))
@@ -233,6 +237,8 @@ static bool srh1_mt6(const struct sk_buff *skb, struct xt_action_param *par) 
	if (srhinfo->mt_flags & IP6T_SRH_LSID) {

		lsidoff = srhoff + sizeof(struct ipv6_sr_hdr);

		lsid = skb_header_pointer(skb, lsidoff, sizeof(_lsid), &_lsid);

		if (!lsid)

			return false;

		if (NF_SRH_INVF(srhinfo, IP6T_SRH_INV_LSID,

				ipv6_masked_addr_cmp(lsid, &srhinfo->lsid_msk,

						     &srhinfo->lsid_addr)))

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