Merge tag 'nf-23-10-04' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf

Florian Westphal says:

====================
netfilter patches for net

First patch resolves a regression with vlan header matching, this was
broken since 6.5 release.  From myself.

Second patch fixes an ancient problem with sctp connection tracking in
case INIT_ACK packets are delayed.  This comes with a selftest, both
patches from Xin Long.

Patch 4 extends the existing nftables audit selftest, from
Phil Sutter.

Patch 5, also from Phil, avoids a situation where nftables
would emit an audit record twice. This was broken since 5.13 days.

Patch 6, from myself, avoids spurious insertion failure if we encounter an
overlapping but expired range during element insertion with the
'nft_set_rbtree' backend. This problem exists since 6.2.

* tag 'nf-23-10-04' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nf_tables: nft_set_rbtree: fix spurious insertion failure
  netfilter: nf_tables: Deduplicate nft_register_obj audit logs
  selftests: netfilter: Extend nft_audit.sh
  selftests: netfilter: test for sctp collision processing in nf_conntrack
  netfilter: handle the connecting collision properly in nf_conntrack_proto_sctp
  netfilter: nft_payload: rebuild vlan header on h_proto access
====================

Link: https://lore.kernel.org/r/20231004141405.28749-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

4 files changed, 102 insertions, 44 deletions

diff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c
index b6bcc8f2f46b7d..c6bd533983c1ff 100644
--- a/net/netfilter/nf_conntrack_proto_sctp.c
+++ b/net/netfilter/nf_conntrack_proto_sctp.c
@@ -112,7 +112,7 @@ static const u8 sctp_conntracks[2][11][SCTP_CONNTRACK_MAX] = {
 /* shutdown_ack */ {sSA, sCL, sCW, sCE, sES, sSA, sSA, sSA, sSA},
 /* error        */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL},/* Can't have Stale cookie*/
 /* cookie_echo  */ {sCL, sCL, sCE, sCE, sES, sSS, sSR, sSA, sCL},/* 5.2.4 - Big TODO */
-/* cookie_ack   */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL},/* Can't come in orig dir */
+/* cookie_ack   */ {sCL, sCL, sCW, sES, sES, sSS, sSR, sSA, sCL},/* Can't come in orig dir */
 /* shutdown_comp*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sCL, sCL},
 /* heartbeat    */ {sHS, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS},
 /* heartbeat_ack*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS},
@@ -126,7 +126,7 @@ static const u8 sctp_conntracks[2][11][SCTP_CONNTRACK_MAX] = {
 /* shutdown     */ {sIV, sCL, sCW, sCE, sSR, sSS, sSR, sSA, sIV},
 /* shutdown_ack */ {sIV, sCL, sCW, sCE, sES, sSA, sSA, sSA, sIV},
 /* error        */ {sIV, sCL, sCW, sCL, sES, sSS, sSR, sSA, sIV},
-/* cookie_echo  */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV},/* Can't come in reply dir */
+/* cookie_echo  */ {sIV, sCL, sCE, sCE, sES, sSS, sSR, sSA, sIV},/* Can't come in reply dir */
 /* cookie_ack   */ {sIV, sCL, sCW, sES, sES, sSS, sSR, sSA, sIV},
 /* shutdown_comp*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sCL, sIV},
 /* heartbeat    */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS},
@@ -412,6 +412,9 @@ int nf_conntrack_sctp_packet(struct nf_conn *ct,
 			/* (D) vtag must be same as init_vtag as found in INIT_ACK */
 			if (sh->vtag != ct->proto.sctp.vtag[dir])
 				goto out_unlock;
+		} else if (sch->type == SCTP_CID_COOKIE_ACK) {
+			ct->proto.sctp.init[dir] = 0;
+			ct->proto.sctp.init[!dir] = 0;
 		} else if (sch->type == SCTP_CID_HEARTBEAT) {
 			if (ct->proto.sctp.vtag[dir] == 0) {
 				pr_debug("Setting %d vtag %x for dir %d\n", sch->type, sh->vtag, dir);
@@ -461,16 +464,18 @@ int nf_conntrack_sctp_packet(struct nf_conn *ct,
 		}
 
 		/* If it is an INIT or an INIT ACK note down the vtag */
-		if (sch->type == SCTP_CID_INIT ||
-		    sch->type == SCTP_CID_INIT_ACK) {
-			struct sctp_inithdr _inithdr, *ih;
+		if (sch->type == SCTP_CID_INIT) {
+			struct sctp_inithdr _ih, *ih;
 
-			ih = skb_header_pointer(skb, offset + sizeof(_sch),
-						sizeof(_inithdr), &_inithdr);
-			if (ih == NULL)
+			ih = skb_header_pointer(skb, offset + sizeof(_sch), sizeof(*ih), &_ih);
+			if (!ih)
 				goto out_unlock;
-			pr_debug("Setting vtag %x for dir %d\n",
-				 ih->init_tag, !dir);
+
+			if (ct->proto.sctp.init[dir] && ct->proto.sctp.init[!dir])
+				ct->proto.sctp.init[!dir] = 0;
+			ct->proto.sctp.init[dir] = 1;
+
+			pr_debug("Setting vtag %x for dir %d\n", ih->init_tag, !dir);
 			ct->proto.sctp.vtag[!dir] = ih->init_tag;
 
 			/* don't renew timeout on init retransmit so
@@ -481,6 +486,24 @@ int nf_conntrack_sctp_packet(struct nf_conn *ct,
 			    old_state == SCTP_CONNTRACK_CLOSED &&
 			    nf_ct_is_confirmed(ct))
 				ignore = true;
+		} else if (sch->type == SCTP_CID_INIT_ACK) {
+			struct sctp_inithdr _ih, *ih;
+			__be32 vtag;
+
+			ih = skb_header_pointer(skb, offset + sizeof(_sch), sizeof(*ih), &_ih);
+			if (!ih)
+				goto out_unlock;
+
+			vtag = ct->proto.sctp.vtag[!dir];
+			if (!ct->proto.sctp.init[!dir] && vtag && vtag != ih->init_tag)
+				goto out_unlock;
+			/* collision */
+			if (ct->proto.sctp.init[dir] && ct->proto.sctp.init[!dir] &&
+			    vtag != ih->init_tag)
+				goto out_unlock;
+
+			pr_debug("Setting vtag %x for dir %d\n", ih->init_tag, !dir);
+			ct->proto.sctp.vtag[!dir] = ih->init_tag;
 		}
 
 		ct->proto.sctp.state = new_state;
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 4356189360fb88..a72b6aeefb1b5d 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -7871,24 +7871,14 @@ static int nf_tables_delobj(struct sk_buff *skb, const struct nfnl_info *info,
 	return nft_delobj(&ctx, obj);
 }
 
-void nft_obj_notify(struct net *net, const struct nft_table *table,
-		    struct nft_object *obj, u32 portid, u32 seq, int event,
-		    u16 flags, int family, int report, gfp_t gfp)
+static void
+__nft_obj_notify(struct net *net, const struct nft_table *table,
+		 struct nft_object *obj, u32 portid, u32 seq, int event,
+		 u16 flags, int family, int report, gfp_t gfp)
 {
 	struct nftables_pernet *nft_net = nft_pernet(net);
 	struct sk_buff *skb;
 	int err;
-	char *buf = kasprintf(gfp, "%s:%u",
-			      table->name, nft_net->base_seq);
-
-	audit_log_nfcfg(buf,
-			family,
-			obj->handle,
-			event == NFT_MSG_NEWOBJ ?
-				 AUDIT_NFT_OP_OBJ_REGISTER :
-				 AUDIT_NFT_OP_OBJ_UNREGISTER,
-			gfp);
-	kfree(buf);
 
 	if (!report &&
 	    !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES))
@@ -7911,13 +7901,35 @@ void nft_obj_notify(struct net *net, const struct nft_table *table,
 err:
 	nfnetlink_set_err(net, portid, NFNLGRP_NFTABLES, -ENOBUFS);
 }
+
+void nft_obj_notify(struct net *net, const struct nft_table *table,
+		    struct nft_object *obj, u32 portid, u32 seq, int event,
+		    u16 flags, int family, int report, gfp_t gfp)
+{
+	struct nftables_pernet *nft_net = nft_pernet(net);
+	char *buf = kasprintf(gfp, "%s:%u",
+			      table->name, nft_net->base_seq);
+
+	audit_log_nfcfg(buf,
+			family,
+			obj->handle,
+			event == NFT_MSG_NEWOBJ ?
+				 AUDIT_NFT_OP_OBJ_REGISTER :
+				 AUDIT_NFT_OP_OBJ_UNREGISTER,
+			gfp);
+	kfree(buf);
+
+	__nft_obj_notify(net, table, obj, portid, seq, event,
+			 flags, family, report, gfp);
+}
 EXPORT_SYMBOL_GPL(nft_obj_notify);
 
 static void nf_tables_obj_notify(const struct nft_ctx *ctx,
 				 struct nft_object *obj, int event)
 {
-	nft_obj_notify(ctx->net, ctx->table, obj, ctx->portid, ctx->seq, event,
-		       ctx->flags, ctx->family, ctx->report, GFP_KERNEL);
+	__nft_obj_notify(ctx->net, ctx->table, obj, ctx->portid,
+			 ctx->seq, event, ctx->flags, ctx->family,
+			 ctx->report, GFP_KERNEL);
 }
 
 /*
diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c
index 8cb80098994793..120f6d395b98b3 100644
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -154,6 +154,17 @@ int nft_payload_inner_offset(const struct nft_pktinfo *pkt)
 	return pkt->inneroff;
 }
 
+static bool nft_payload_need_vlan_copy(const struct nft_payload *priv)
+{
+	unsigned int len = priv->offset + priv->len;
+
+	/* data past ether src/dst requested, copy needed */
+	if (len > offsetof(struct ethhdr, h_proto))
+		return true;
+
+	return false;
+}
+
 void nft_payload_eval(const struct nft_expr *expr,
 		      struct nft_regs *regs,
 		      const struct nft_pktinfo *pkt)
@@ -172,7 +183,7 @@ void nft_payload_eval(const struct nft_expr *expr,
 			goto err;
 
 		if (skb_vlan_tag_present(skb) &&
-		    priv->offset >= offsetof(struct ethhdr, h_proto)) {
+		    nft_payload_need_vlan_copy(priv)) {
 			if (!nft_payload_copy_vlan(dest, skb,
 						   priv->offset, priv->len))
 				goto err;
diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c
index 487572dcd61443..2660ceab3759db 100644
--- a/net/netfilter/nft_set_rbtree.c
+++ b/net/netfilter/nft_set_rbtree.c
@@ -233,10 +233,9 @@ static void nft_rbtree_gc_remove(struct net *net, struct nft_set *set,
 	rb_erase(&rbe->node, &priv->root);
 }
 
-static int nft_rbtree_gc_elem(const struct nft_set *__set,
-			      struct nft_rbtree *priv,
-			      struct nft_rbtree_elem *rbe,
-			      u8 genmask)
+static const struct nft_rbtree_elem *
+nft_rbtree_gc_elem(const struct nft_set *__set, struct nft_rbtree *priv,
+		   struct nft_rbtree_elem *rbe, u8 genmask)
 {
 	struct nft_set *set = (struct nft_set *)__set;
 	struct rb_node *prev = rb_prev(&rbe->node);
@@ -246,7 +245,7 @@ static int nft_rbtree_gc_elem(const struct nft_set *__set,
 
 	gc = nft_trans_gc_alloc(set, 0, GFP_ATOMIC);
 	if (!gc)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
 	/* search for end interval coming before this element.
 	 * end intervals don't carry a timeout extension, they
@@ -261,6 +260,7 @@ static int nft_rbtree_gc_elem(const struct nft_set *__set,
 		prev = rb_prev(prev);
 	}
 
+	rbe_prev = NULL;
 	if (prev) {
 		rbe_prev = rb_entry(prev, struct nft_rbtree_elem, node);
 		nft_rbtree_gc_remove(net, set, priv, rbe_prev);
@@ -272,7 +272,7 @@ static int nft_rbtree_gc_elem(const struct nft_set *__set,
 		 */
 		gc = nft_trans_gc_queue_sync(gc, GFP_ATOMIC);
 		if (WARN_ON_ONCE(!gc))
-			return -ENOMEM;
+			return ERR_PTR(-ENOMEM);
 
 		nft_trans_gc_elem_add(gc, rbe_prev);
 	}
@@ -280,13 +280,13 @@ static int nft_rbtree_gc_elem(const struct nft_set *__set,
 	nft_rbtree_gc_remove(net, set, priv, rbe);
 	gc = nft_trans_gc_queue_sync(gc, GFP_ATOMIC);
 	if (WARN_ON_ONCE(!gc))
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
 	nft_trans_gc_elem_add(gc, rbe);
 
 	nft_trans_gc_queue_sync_done(gc);
 
-	return 0;
+	return rbe_prev;
 }
 
 static bool nft_rbtree_update_first(const struct nft_set *set,
@@ -314,7 +314,7 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 	struct nft_rbtree *priv = nft_set_priv(set);
 	u8 cur_genmask = nft_genmask_cur(net);
 	u8 genmask = nft_genmask_next(net);
-	int d, err;
+	int d;
 
 	/* Descend the tree to search for an existing element greater than the
 	 * key value to insert that is greater than the new element. This is the
@@ -363,9 +363,14 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 		 */
 		if (nft_set_elem_expired(&rbe->ext) &&
 		    nft_set_elem_active(&rbe->ext, cur_genmask)) {
-			err = nft_rbtree_gc_elem(set, priv, rbe, genmask);
-			if (err < 0)
-				return err;
+			const struct nft_rbtree_elem *removed_end;
+
+			removed_end = nft_rbtree_gc_elem(set, priv, rbe, genmask);
+			if (IS_ERR(removed_end))
+				return PTR_ERR(removed_end);
+
+			if (removed_end == rbe_le || removed_end == rbe_ge)
+				return -EAGAIN;
 
 			continue;
 		}
@@ -486,11 +491,18 @@ static int nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 	struct nft_rbtree_elem *rbe = elem->priv;
 	int err;
 
-	write_lock_bh(&priv->lock);
-	write_seqcount_begin(&priv->count);
-	err = __nft_rbtree_insert(net, set, rbe, ext);
-	write_seqcount_end(&priv->count);
-	write_unlock_bh(&priv->lock);
+	do {
+		if (fatal_signal_pending(current))
+			return -EINTR;
+
+		cond_resched();
+
+		write_lock_bh(&priv->lock);
+		write_seqcount_begin(&priv->count);
+		err = __nft_rbtree_insert(net, set, rbe, ext);
+		write_seqcount_end(&priv->count);
+		write_unlock_bh(&priv->lock);
+	} while (err == -EAGAIN);
 
 	return err;
 }