Patch "netfilter: nf_tables: fully validate NFT_DATA_VALUE on store to data registers" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    netfilter: nf_tables: fully validate NFT_DATA_VALUE on store to data registers

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     netfilter-nf_tables-fully-validate-nft_data_value-on.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 2d83807192d1e26bfa3e7c9400d88cde12ba33bd
Author: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Date:   Wed Jun 26 23:15:38 2024 +0200

    netfilter: nf_tables: fully validate NFT_DATA_VALUE on store to data registers
    
    [ Upstream commit 7931d32955e09d0a11b1fe0b6aac1bfa061c005c ]
    
    register store validation for NFT_DATA_VALUE is conditional, however,
    the datatype is always either NFT_DATA_VALUE or NFT_DATA_VERDICT. This
    only requires a new helper function to infer the register type from the
    set datatype so this conditional check can be removed. Otherwise,
    pointer to chain object can be leaked through the registers.
    
    Fixes: 96518518cc41 ("netfilter: add nftables")
    Reported-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxx>
    Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 964cf7578bd50..9a80d0251d8f3 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -582,6 +582,11 @@ static inline void *nft_set_priv(const struct nft_set *set)
 	return (void *)set->data;
 }
 
+static inline enum nft_data_types nft_set_datatype(const struct nft_set *set)
+{
+	return set->dtype == NFT_DATA_VERDICT ? NFT_DATA_VERDICT : NFT_DATA_VALUE;
+}
+
 static inline bool nft_set_gc_is_pending(const struct nft_set *s)
 {
 	return refcount_read(&s->refs) != 1;
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index e838a6617b0aa..97ea72d31bd35 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -5398,8 +5398,7 @@ static int nf_tables_fill_setelem(struct sk_buff *skb,
 
 	if (nft_set_ext_exists(ext, NFT_SET_EXT_DATA) &&
 	    nft_data_dump(skb, NFTA_SET_ELEM_DATA, nft_set_ext_data(ext),
-			  set->dtype == NFT_DATA_VERDICT ? NFT_DATA_VERDICT : NFT_DATA_VALUE,
-			  set->dlen) < 0)
+			  nft_set_datatype(set), set->dlen) < 0)
 		goto nla_put_failure;
 
 	if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPRESSIONS) &&
@@ -10448,6 +10447,9 @@ static int nft_validate_register_store(const struct nft_ctx *ctx,
 
 		return 0;
 	default:
+		if (type != NFT_DATA_VALUE)
+			return -EINVAL;
+
 		if (reg < NFT_REG_1 * NFT_REG_SIZE / NFT_REG32_SIZE)
 			return -EINVAL;
 		if (len == 0)
@@ -10456,8 +10458,6 @@ static int nft_validate_register_store(const struct nft_ctx *ctx,
 		    sizeof_field(struct nft_regs, data))
 			return -ERANGE;
 
-		if (data != NULL && type != NFT_DATA_VALUE)
-			return -EINVAL;
 		return 0;
 	}
 }
diff --git a/net/netfilter/nft_lookup.c b/net/netfilter/nft_lookup.c
index 68a5dea805480..33daee2e54c5c 100644
--- a/net/netfilter/nft_lookup.c
+++ b/net/netfilter/nft_lookup.c
@@ -136,7 +136,8 @@ static int nft_lookup_init(const struct nft_ctx *ctx,
 			return -EINVAL;
 
 		err = nft_parse_register_store(ctx, tb[NFTA_LOOKUP_DREG],
-					       &priv->dreg, NULL, set->dtype,
+					       &priv->dreg, NULL,
+					       nft_set_datatype(set),
 					       set->dlen);
 		if (err < 0)
 			return err;