Merge tag 'ipsec-2023-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

Steffen Klassert says:

====================
ipsec 2023-02-08

1) Fix policy checks for nested IPsec tunnels when using
   xfrm interfaces. From Benedict Wong.

2) Fix netlink message expression on 32=>64-bit
   messages translators. From Anastasia Belova.

3) Prevent potential spectre v1 gadget in xfrm_xlate32_attr.
   From Eric Dumazet.

4) Always consistently use time64_t in xfrm_timer_handler.
   From Eric Dumazet.

5) Fix KCSAN reported bug: Multiple cpus can update use_time
   at the same time. From Eric Dumazet.

6) Fix SCP copy from IPv4 to IPv6 on interfamily tunnel.
   From Christian Hopps.

* tag 'ipsec-2023-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec:
  xfrm: fix bug with DSCP copy to v6 from v4 tunnel
  xfrm: annotate data-race around use_time
  xfrm: consistently use time64_t in xfrm_timer_handler()
  xfrm/compat: prevent potential spectre v1 gadget in xfrm_xlate32_attr()
  xfrm: compat: change expression for switch in xfrm_xlate64
  Fix XFRM-I support for nested ESP tunnels
====================

Link: https://lore.kernel.org/r/20230208114322.266510-1-steffen.klassert@secunet.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

5 files changed, 73 insertions, 20 deletions

diff --git a/net/xfrm/xfrm_compat.c b/net/xfrm/xfrm_compat.c
index a0f62fa02e06..8cbf45a8bcdc 100644
--- a/net/xfrm/xfrm_compat.c
+++ b/net/xfrm/xfrm_compat.c
@@ -5,6 +5,7 @@
  * Based on code and translator idea by: Florian Westphal <fw@strlen.de>
  */
 #include <linux/compat.h>
+#include <linux/nospec.h>
 #include <linux/xfrm.h>
 #include <net/xfrm.h>
 
@@ -302,7 +303,7 @@ static int xfrm_xlate64(struct sk_buff *dst, const struct nlmsghdr *nlh_src)
 	nla_for_each_attr(nla, attrs, len, remaining) {
 		int err;
 
-		switch (type) {
+		switch (nlh_src->nlmsg_type) {
 		case XFRM_MSG_NEWSPDINFO:
 			err = xfrm_nla_cpy(dst, nla, nla_len(nla));
 			break;
@@ -437,6 +438,7 @@ static int xfrm_xlate32_attr(void *dst, const struct nlattr *nla,
 		NL_SET_ERR_MSG(extack, "Bad attribute");
 		return -EOPNOTSUPP;
 	}
+	type = array_index_nospec(type, XFRMA_MAX + 1);
 	if (nla_len(nla) < compat_policy[type].len) {
 		NL_SET_ERR_MSG(extack, "Attribute bad length");
 		return -EOPNOTSUPP;
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index c06e54a10540..436d29640ac2 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -279,8 +279,7 @@ static int xfrm6_remove_tunnel_encap(struct xfrm_state *x, struct sk_buff *skb)
 		goto out;
 
 	if (x->props.flags & XFRM_STATE_DECAP_DSCP)
-		ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)),
-			       ipipv6_hdr(skb));
+		ipv6_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, ipipv6_hdr(skb));
 	if (!(x->props.flags & XFRM_STATE_NOECN))
 		ipip6_ecn_decapsulate(skb);
 
diff --git a/net/xfrm/xfrm_interface_core.c b/net/xfrm/xfrm_interface_core.c
index 1f99dc469027..35279c220bd7 100644
--- a/net/xfrm/xfrm_interface_core.c
+++ b/net/xfrm/xfrm_interface_core.c
@@ -310,6 +310,52 @@ static void xfrmi_scrub_packet(struct sk_buff *skb, bool xnet)
 	skb->mark = 0;
 }
 
+static int xfrmi_input(struct sk_buff *skb, int nexthdr, __be32 spi,
+		       int encap_type, unsigned short family)
+{
+	struct sec_path *sp;
+
+	sp = skb_sec_path(skb);
+	if (sp && (sp->len || sp->olen) &&
+	    !xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family))
+		goto discard;
+
+	XFRM_SPI_SKB_CB(skb)->family = family;
+	if (family == AF_INET) {
+		XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
+		XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
+	} else {
+		XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
+		XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
+	}
+
+	return xfrm_input(skb, nexthdr, spi, encap_type);
+discard:
+	kfree_skb(skb);
+	return 0;
+}
+
+static int xfrmi4_rcv(struct sk_buff *skb)
+{
+	return xfrmi_input(skb, ip_hdr(skb)->protocol, 0, 0, AF_INET);
+}
+
+static int xfrmi6_rcv(struct sk_buff *skb)
+{
+	return xfrmi_input(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
+			   0, 0, AF_INET6);
+}
+
+static int xfrmi4_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
+{
+	return xfrmi_input(skb, nexthdr, spi, encap_type, AF_INET);
+}
+
+static int xfrmi6_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
+{
+	return xfrmi_input(skb, nexthdr, spi, encap_type, AF_INET6);
+}
+
 static int xfrmi_rcv_cb(struct sk_buff *skb, int err)
 {
 	const struct xfrm_mode *inner_mode;
@@ -945,8 +991,8 @@ static struct pernet_operations xfrmi_net_ops = {
 };
 
 static struct xfrm6_protocol xfrmi_esp6_protocol __read_mostly = {
-	.handler	=	xfrm6_rcv,
-	.input_handler	=	xfrm_input,
+	.handler	=	xfrmi6_rcv,
+	.input_handler	=	xfrmi6_input,
 	.cb_handler	=	xfrmi_rcv_cb,
 	.err_handler	=	xfrmi6_err,
 	.priority	=	10,
@@ -996,8 +1042,8 @@ static struct xfrm6_tunnel xfrmi_ip6ip_handler __read_mostly = {
 #endif
 
 static struct xfrm4_protocol xfrmi_esp4_protocol __read_mostly = {
-	.handler	=	xfrm4_rcv,
-	.input_handler	=	xfrm_input,
+	.handler	=	xfrmi4_rcv,
+	.input_handler	=	xfrmi4_input,
 	.cb_handler	=	xfrmi_rcv_cb,
 	.err_handler	=	xfrmi4_err,
 	.priority	=	10,
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index e9eb82c5457d..5c61ec04b839 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -336,7 +336,7 @@ static void xfrm_policy_timer(struct timer_list *t)
 	}
 	if (xp->lft.hard_use_expires_seconds) {
 		time64_t tmo = xp->lft.hard_use_expires_seconds +
-			(xp->curlft.use_time ? : xp->curlft.add_time) - now;
+			(READ_ONCE(xp->curlft.use_time) ? : xp->curlft.add_time) - now;
 		if (tmo <= 0)
 			goto expired;
 		if (tmo < next)
@@ -354,7 +354,7 @@ static void xfrm_policy_timer(struct timer_list *t)
 	}
 	if (xp->lft.soft_use_expires_seconds) {
 		time64_t tmo = xp->lft.soft_use_expires_seconds +
-			(xp->curlft.use_time ? : xp->curlft.add_time) - now;
+			(READ_ONCE(xp->curlft.use_time) ? : xp->curlft.add_time) - now;
 		if (tmo <= 0) {
 			warn = 1;
 			tmo = XFRM_KM_TIMEOUT;
@@ -3661,7 +3661,8 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
 		return 1;
 	}
 
-	pol->curlft.use_time = ktime_get_real_seconds();
+	/* This lockless write can happen from different cpus. */
+	WRITE_ONCE(pol->curlft.use_time, ktime_get_real_seconds());
 
 	pols[0] = pol;
 	npols++;
@@ -3676,7 +3677,9 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
 				xfrm_pol_put(pols[0]);
 				return 0;
 			}
-			pols[1]->curlft.use_time = ktime_get_real_seconds();
+			/* This write can happen from different cpus. */
+			WRITE_ONCE(pols[1]->curlft.use_time,
+				   ktime_get_real_seconds());
 			npols++;
 		}
 	}
@@ -3742,6 +3745,9 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
 			goto reject;
 		}
 
+		if (if_id)
+			secpath_reset(skb);
+
 		xfrm_pols_put(pols, npols);
 		return 1;
 	}
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 89c731f4f0c7..00afe831c71c 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -577,7 +577,7 @@ static enum hrtimer_restart xfrm_timer_handler(struct hrtimer *me)
 	if (x->km.state == XFRM_STATE_EXPIRED)
 		goto expired;
 	if (x->lft.hard_add_expires_seconds) {
-		long tmo = x->lft.hard_add_expires_seconds +
+		time64_t tmo = x->lft.hard_add_expires_seconds +
 			x->curlft.add_time - now;
 		if (tmo <= 0) {
 			if (x->xflags & XFRM_SOFT_EXPIRE) {
@@ -594,8 +594,8 @@ static enum hrtimer_restart xfrm_timer_handler(struct hrtimer *me)
 			next = tmo;
 	}
 	if (x->lft.hard_use_expires_seconds) {
-		long tmo = x->lft.hard_use_expires_seconds +
-			(x->curlft.use_time ? : now) - now;
+		time64_t tmo = x->lft.hard_use_expires_seconds +
+			(READ_ONCE(x->curlft.use_time) ? : now) - now;
 		if (tmo <= 0)
 			goto expired;
 		if (tmo < next)
@@ -604,7 +604,7 @@ static enum hrtimer_restart xfrm_timer_handler(struct hrtimer *me)
 	if (x->km.dying)
 		goto resched;
 	if (x->lft.soft_add_expires_seconds) {
-		long tmo = x->lft.soft_add_expires_seconds +
+		time64_t tmo = x->lft.soft_add_expires_seconds +
 			x->curlft.add_time - now;
 		if (tmo <= 0) {
 			warn = 1;
@@ -616,8 +616,8 @@ static enum hrtimer_restart xfrm_timer_handler(struct hrtimer *me)
 		}
 	}
 	if (x->lft.soft_use_expires_seconds) {
-		long tmo = x->lft.soft_use_expires_seconds +
-			(x->curlft.use_time ? : now) - now;
+		time64_t tmo = x->lft.soft_use_expires_seconds +
+			(READ_ONCE(x->curlft.use_time) ? : now) - now;
 		if (tmo <= 0)
 			warn = 1;
 		else if (tmo < next)
@@ -1906,7 +1906,7 @@ out:
 
 		hrtimer_start(&x1->mtimer, ktime_set(1, 0),
 			      HRTIMER_MODE_REL_SOFT);
-		if (x1->curlft.use_time)
+		if (READ_ONCE(x1->curlft.use_time))
 			xfrm_state_check_expire(x1);
 
 		if (x->props.smark.m || x->props.smark.v || x->if_id) {
@@ -1940,8 +1940,8 @@ int xfrm_state_check_expire(struct xfrm_state *x)
 {
 	xfrm_dev_state_update_curlft(x);
 
-	if (!x->curlft.use_time)
-		x->curlft.use_time = ktime_get_real_seconds();
+	if (!READ_ONCE(x->curlft.use_time))
+		WRITE_ONCE(x->curlft.use_time, ktime_get_real_seconds());
 
 	if (x->curlft.bytes >= x->lft.hard_byte_limit ||
 	    x->curlft.packets >= x->lft.hard_packet_limit) {