[PATCH AUTOSEL 5.15 4/5] netfilter: nf_tables: deactivate anonymous set from preparation phase

[Sasha Levin <sashal@kernel.org>]

From: Pablo Neira Ayuso <pablo@netfilter.org>

[ Upstream commit c1592a89942e9678f7d9c8030efa777c0d57edab ]

Toggle deleted anonymous sets as inactive in the next generation, so
users cannot perform any update on it. Clear the generation bitmask
in case the transaction is aborted.

The following KASAN splat shows a set element deletion for a bound
anonymous set that has been already removed in the same transaction.

[   64.921510] ==================================================================
[   64.923123] BUG: KASAN: wild-memory-access in nf_tables_commit+0xa24/0x1490 [nf_tables]
[   64.924745] Write of size 8 at addr dead000000000122 by task test/890
[   64.927903] CPU: 3 PID: 890 Comm: test Not tainted 6.3.0+ #253
[   64.931120] Call Trace:
[   64.932699]  <TASK>
[   64.934292]  dump_stack_lvl+0x33/0x50
[   64.935908]  ? nf_tables_commit+0xa24/0x1490 [nf_tables]
[   64.937551]  kasan_report+0xda/0x120
[   64.939186]  ? nf_tables_commit+0xa24/0x1490 [nf_tables]
[   64.940814]  nf_tables_commit+0xa24/0x1490 [nf_tables]
[   64.942452]  ? __kasan_slab_alloc+0x2d/0x60
[   64.944070]  ? nf_tables_setelem_notify+0x190/0x190 [nf_tables]
[   64.945710]  ? kasan_set_track+0x21/0x30
[   64.947323]  nfnetlink_rcv_batch+0x709/0xd90 [nfnetlink]
[   64.948898]  ? nfnetlink_rcv_msg+0x480/0x480 [nfnetlink]

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 include/net/netfilter/nf_tables.h |  1 +
 net/netfilter/nf_tables_api.c     | 12 ++++++++++++
 net/netfilter/nft_dynset.c        |  2 +-
 net/netfilter/nft_lookup.c        |  2 +-
 net/netfilter/nft_objref.c        |  2 +-
 5 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 8def00a04541e..22f67ae935e0b 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -584,6 +584,7 @@ struct nft_set_binding {
 };
 
 enum nft_trans_phase;
+void nf_tables_activate_set(const struct nft_ctx *ctx, struct nft_set *set);
 void nf_tables_deactivate_set(const struct nft_ctx *ctx, struct nft_set *set,
 			      struct nft_set_binding *binding,
 			      enum nft_trans_phase phase);
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index d950041364d5f..9c38b227275e8 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4839,12 +4839,24 @@ static void nf_tables_unbind_set(const struct nft_ctx *ctx, struct nft_set *set,
 	}
 }
 
+void nf_tables_activate_set(const struct nft_ctx *ctx, struct nft_set *set)
+{
+	if (nft_set_is_anonymous(set))
+		nft_clear(ctx->net, set);
+
+	set->use++;
+}
+EXPORT_SYMBOL_GPL(nf_tables_activate_set);
+
 void nf_tables_deactivate_set(const struct nft_ctx *ctx, struct nft_set *set,
 			      struct nft_set_binding *binding,
 			      enum nft_trans_phase phase)
 {
 	switch (phase) {
 	case NFT_TRANS_PREPARE:
+		if (nft_set_is_anonymous(set))
+			nft_deactivate_next(ctx->net, set);
+
 		set->use--;
 		return;
 	case NFT_TRANS_ABORT:
diff --git a/net/netfilter/nft_dynset.c b/net/netfilter/nft_dynset.c
index 87f3af4645d9c..29c7ae8789e95 100644
--- a/net/netfilter/nft_dynset.c
+++ b/net/netfilter/nft_dynset.c
@@ -342,7 +342,7 @@ static void nft_dynset_activate(const struct nft_ctx *ctx,
 {
 	struct nft_dynset *priv = nft_expr_priv(expr);
 
-	priv->set->use++;
+	nf_tables_activate_set(ctx, priv->set);
 }
 
 static void nft_dynset_destroy(const struct nft_ctx *ctx,
diff --git a/net/netfilter/nft_lookup.c b/net/netfilter/nft_lookup.c
index bd3485dd930f5..9d18c5428d53c 100644
--- a/net/netfilter/nft_lookup.c
+++ b/net/netfilter/nft_lookup.c
@@ -167,7 +167,7 @@ static void nft_lookup_activate(const struct nft_ctx *ctx,
 {
 	struct nft_lookup *priv = nft_expr_priv(expr);
 
-	priv->set->use++;
+	nf_tables_activate_set(ctx, priv->set);
 }
 
 static void nft_lookup_destroy(const struct nft_ctx *ctx,
diff --git a/net/netfilter/nft_objref.c b/net/netfilter/nft_objref.c
index 94b2327e71dc4..3ff91bcaa5f24 100644
--- a/net/netfilter/nft_objref.c
+++ b/net/netfilter/nft_objref.c
@@ -183,7 +183,7 @@ static void nft_objref_map_activate(const struct nft_ctx *ctx,
 {
 	struct nft_objref_map *priv = nft_expr_priv(expr);
 
-	priv->set->use++;
+	nf_tables_activate_set(ctx, priv->set);
 }
 
 static void nft_objref_map_destroy(const struct nft_ctx *ctx,
-- 
2.39.2