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Commit 833c1e23 authored by Dmitry Safonov's avatar Dmitry Safonov Committed by Connor O'Brien
Browse files

UPSTREAM: net/xfrm/compat: Copy xfrm_spdattr_type_t atributes 



The attribute-translator has to take in mind maxtype, that is
xfrm_link::nla_max. When it is set, attributes are not of xfrm_attr_type_t.
Currently, they can be only XFRMA_SPD_MAX (message XFRM_MSG_NEWSPDINFO),
their UABI is the same for 64/32-bit, so just copy them.

Thanks to YueHaibing for reporting this:
In xfrm_user_rcv_msg_compat() if maxtype is not zero and less than
XFRMA_MAX, nlmsg_parse_deprecated() do not initialize attrs array fully.
xfrm_xlate32() will access uninit 'attrs[i]' while iterating all attrs
array.

KASAN: probably user-memory-access in range [0x0000000041b58ab0-0x0000000041b58ab7]
CPU: 0 PID: 15799 Comm: syz-executor.2 Tainted: G        W         5.14.0-rc1-syzkaller #0
RIP: 0010:nla_type include/net/netlink.h:1130 [inline]
RIP: 0010:xfrm_xlate32_attr net/xfrm/xfrm_compat.c:410 [inline]
RIP: 0010:xfrm_xlate32 net/xfrm/xfrm_compat.c:532 [inline]
RIP: 0010:xfrm_user_rcv_msg_compat+0x5e5/0x1070 net/xfrm/xfrm_compat.c:577
[...]
Call Trace:
 xfrm_user_rcv_msg+0x556/0x8b0 net/xfrm/xfrm_user.c:2774
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
 xfrm_netlink_rcv+0x6b/0x90 net/xfrm/xfrm_user.c:2824
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929
 sock_sendmsg_nosec net/socket.c:702 [inline]

Fixes: 5106f4a8acff ("xfrm/compat: Add 32=>64-bit messages translator")
Cc: <stable@kernel.org>
Reported-by: default avatarYueHaibing <yuehaibing@huawei.com>
Signed-off-by: default avatarDmitry Safonov <dima@arista.com>
Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
(cherry picked from commit 4e9505064f58d1252805952f8547a5b7dbc5c111)
Bug: 187129171
Signed-off-by: default avatarConnor O'Brien <connoro@google.com>
Change-Id: I7a1bb8cd01a518c372f4b17b2363a0c3ce7cd9b4
parent a95d35ae

net/xfrm/xfrm_compat.c

+44 −5
Original line number Diff line number Diff line
@@ -298,8 +298,16 @@ static int xfrm_xlate64(struct sk_buff *dst, const struct nlmsghdr *nlh_src) 
	len = nlmsg_attrlen(nlh_src, xfrm_msg_min[type]);



	nla_for_each_attr(nla, attrs, len, remaining) {

		int err = xfrm_xlate64_attr(dst, nla);

		int err;



		switch (type) {

		case XFRM_MSG_NEWSPDINFO:

			err = xfrm_nla_cpy(dst, nla, nla_len(nla));

			break;

		default:

			err = xfrm_xlate64_attr(dst, nla);

			break;

		}

		if (err)

			return err;

	}
@@ -341,7 +349,8 @@ static int xfrm_alloc_compat(struct sk_buff *skb, const struct nlmsghdr *nlh_src 


/* Calculates len of translated 64-bit message. */

static size_t xfrm_user_rcv_calculate_len64(const struct nlmsghdr *src,

					    struct nlattr *attrs[XFRMA_MAX+1])

					    struct nlattr *attrs[XFRMA_MAX + 1],

					    int maxtype)

{

	size_t len = nlmsg_len(src);
@@ -358,10 +367,20 @@ static size_t xfrm_user_rcv_calculate_len64(const struct nlmsghdr *src, 
	case XFRM_MSG_POLEXPIRE:

		len += 8;

		break;

	case XFRM_MSG_NEWSPDINFO:

		/* attirbutes are xfrm_spdattr_type_t, not xfrm_attr_type_t */

		return len;

	default:

		break;

	}



	/* Unexpected for anything, but XFRM_MSG_NEWSPDINFO, please

	 * correct both 64=>32-bit and 32=>64-bit translators to copy

	 * new attributes.

	 */

	if (WARN_ON_ONCE(maxtype))

		return len;



	if (attrs[XFRMA_SA])

		len += 4;

	if (attrs[XFRMA_POLICY])
@@ -440,7 +459,8 @@ static int xfrm_xlate32_attr(void *dst, const struct nlattr *nla, 


static int xfrm_xlate32(struct nlmsghdr *dst, const struct nlmsghdr *src,

			struct nlattr *attrs[XFRMA_MAX+1],

			size_t size, u8 type, struct netlink_ext_ack *extack)

			size_t size, u8 type, int maxtype,

			struct netlink_ext_ack *extack)

{

	size_t pos;

	int i;
@@ -520,6 +540,25 @@ static int xfrm_xlate32(struct nlmsghdr *dst, const struct nlmsghdr *src, 
	}

	pos = dst->nlmsg_len;



	if (maxtype) {

		/* attirbutes are xfrm_spdattr_type_t, not xfrm_attr_type_t */

		WARN_ON_ONCE(src->nlmsg_type != XFRM_MSG_NEWSPDINFO);



		for (i = 1; i <= maxtype; i++) {

			int err;



			if (!attrs[i])

				continue;



			/* just copy - no need for translation */

			err = xfrm_attr_cpy32(dst, &pos, attrs[i], size,

					nla_len(attrs[i]), nla_len(attrs[i]));

			if (err)

				return err;

		}

		return 0;

	}



	for (i = 1; i < XFRMA_MAX + 1; i++) {

		int err;
@@ -564,7 +603,7 @@ static struct nlmsghdr *xfrm_user_rcv_msg_compat(const struct nlmsghdr *h32, 
	if (err < 0)

		return ERR_PTR(err);



	len = xfrm_user_rcv_calculate_len64(h32, attrs);

	len = xfrm_user_rcv_calculate_len64(h32, attrs, maxtype);

	/* The message doesn't need translation */

	if (len == nlmsg_len(h32))

		return NULL;
@@ -574,7 +613,7 @@ static struct nlmsghdr *xfrm_user_rcv_msg_compat(const struct nlmsghdr *h32, 
	if (!h64)

		return ERR_PTR(-ENOMEM);



	err = xfrm_xlate32(h64, h32, attrs, len, type, extack);

	err = xfrm_xlate32(h64, h32, attrs, len, type, maxtype, extack);

	if (err < 0) {

		kvfree(h64);

		return ERR_PTR(err);