backport "netfilter: nf_tables: deactivate anonymous set from preparation phase"

Link: https://ubuntu.com/security/CVE-2023-32233
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

diff --git a/patches/kernel/0008-netfilter-nf_tables-deactivate-anonymous-set-from-pr.patch b/patches/kernel/0008-netfilter-nf_tables-deactivate-anonymous-set-from-pr.patch
new file mode 100644 (file)
index 0000000..dca4e0d
--- /dev/null
+++ b/patches/kernel/0008-netfilter-nf_tables-deactivate-anonymous-set-from-pr.patch
@@ -0,0 +1,120 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Pablo Neira Ayuso <pablo@netfilter.org>
+Date: Tue, 2 May 2023 10:25:24 +0200
+Subject: [PATCH] netfilter: nf_tables: deactivate anonymous set from
+ preparation phase
+
+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: Thomas Lamprecht <t.lamprecht@proxmox.com>
+---
+ 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 9430128aae99..06815130e861 100644
+--- a/include/net/netfilter/nf_tables.h
++++ b/include/net/netfilter/nf_tables.h
+@@ -619,6 +619,7 @@ 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 6023c9f72cdc..26255c2a6692 100644
+--- a/net/netfilter/nf_tables_api.c
++++ b/net/netfilter/nf_tables_api.c
+@@ -4932,12 +4932,24 @@ 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 274579b1696e..bd19c7aec92e 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 cae5a6724163..925392bab58a 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 7b01aa2ef653..d985d361ed8a 100644
+--- a/net/netfilter/nft_objref.c
++++ b/net/netfilter/nft_objref.c
+@@ -185,7 +185,7 @@ 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,