[IPV6] ADDRCONF: Check range of prefix length (24ef0da7) · Commits · 戴 / test

As of now, the prefix length is not vaildated when adding or deleting addresses. The value is passed directly into the inet6_ifaddr structure and later passed on to memcmp() as length indicator which relies on the value never to exceed 128 (bits). Due to the missing check, the currently code allows for any 8 bit value to be passed on as prefix length while using the netlink interface, and any 32 bit value while using the ioctl interface. [Use unsigned int instead to generate better code - yoshfuji] Signed-off-by:

Thomas Graf <tgraf@suug.ch> Signed-off-by:

YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

net/ipv6/addrconf.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -2027,7 +2027,7 @@ err_exit:
		* Manual configuration of address on an interface
		*/
		static int inet6_addr_add(struct net net, int ifindex, struct in6_addr pfx,
		int plen, __u8 ifa_flags, __u32 prefered_lft,
		unsigned int plen, __u8 ifa_flags, __u32 prefered_lft,
		__u32 valid_lft)
		{
		struct inet6_ifaddr *ifp;
		@@ -2039,6 +2039,9 @@ static int inet6_addr_add(struct net net, int ifindex, struct in6_addr pfx,

		ASSERT_RTNL();

		if (plen > 128)
		return -EINVAL;

		/* check the lifetime */
		if (!valid_lft \|\| prefered_lft > valid_lft)
		return -EINVAL;
		@@ -2095,12 +2098,15 @@ static int inet6_addr_add(struct net net, int ifindex, struct in6_addr pfx,
		}

		static int inet6_addr_del(struct net net, int ifindex, struct in6_addr pfx,
		int plen)
		unsigned int plen)
		{
		struct inet6_ifaddr *ifp;
		struct inet6_dev *idev;
		struct net_device *dev;

		if (plen > 128)
		return -EINVAL;

		dev = __dev_get_by_index(net, ifindex);
		if (!dev)
		return -ENODEV;

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