The set description provides the size of each field in the set whose sum
should not mismatch the set key length, bail out otherwise.
I did not manage to crash nft_set_pipapo with mismatch fields and set key
length so far, but this is UB which must be disallowed.
Fixes: f3a2181e16f1 ("netfilter: nf_tables: Support for sets with multiple ranged fields")
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
net/netfilter/nf_tables_api.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index cc4ad2c34867..d67f5504b2d6 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4804,8 +4804,8 @@ static int nft_set_desc_concat_parse(const struct nlattr *attr,
static int nft_set_desc_concat(struct nft_set_desc *desc,
const struct nlattr *nla)
{
+ u32 num_regs = 0, key_num_regs = 0;
struct nlattr *attr;
- u32 num_regs = 0;
int rem, err, i;
nla_for_each_nested(attr, nla, rem) {
@@ -4820,6 +4820,10 @@ static int nft_set_desc_concat(struct nft_set_desc *desc,
for (i = 0; i < desc->field_count; i++)
num_regs += DIV_ROUND_UP(desc->field_len[i], sizeof(u32));
+ key_num_regs = DIV_ROUND_UP(desc->klen, sizeof(u32));
+ if (key_num_regs != num_regs)
+ return -EINVAL;
+
if (num_regs > NFT_REG32_COUNT)
return -E2BIG;
--
2.30.2
