From: Pablo Neira Ayuso pablo@netfilter.org
commit fecf31ee395b0295f2d7260aa29946b7605f7c85 upstream.
Add several sanity checks for nft_set_desc_concat_parse():
- validate desc->field_count not larger than desc->field_len array. - field length cannot be larger than desc->field_len (ie. U8_MAX) - total length of the concatenation cannot be larger than register array.
Joint work with Florian Westphal.
Fixes: f3a2181e16f1 ("netfilter: nf_tables: Support for sets with multiple ranged fields") Reported-by: zhangziming.zzm@antgroup.com Reviewed-by: Stefano Brivio sbrivio@redhat.com Signed-off-by: Florian Westphal fw@strlen.de Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netfilter/nf_tables_api.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-)
--- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -4151,6 +4151,9 @@ static int nft_set_desc_concat_parse(con u32 len; int err;
+ if (desc->field_count >= ARRAY_SIZE(desc->field_len)) + return -E2BIG; + err = nla_parse_nested_deprecated(tb, NFTA_SET_FIELD_MAX, attr, nft_concat_policy, NULL); if (err < 0) @@ -4160,9 +4163,8 @@ static int nft_set_desc_concat_parse(con return -EINVAL;
len = ntohl(nla_get_be32(tb[NFTA_SET_FIELD_LEN])); - - if (len * BITS_PER_BYTE / 32 > NFT_REG32_COUNT) - return -E2BIG; + if (!len || len > U8_MAX) + return -EINVAL;
desc->field_len[desc->field_count++] = len;
@@ -4173,7 +4175,8 @@ static int nft_set_desc_concat(struct nf const struct nlattr *nla) { struct nlattr *attr; - int rem, err; + u32 num_regs = 0; + int rem, err, i;
nla_for_each_nested(attr, nla, rem) { if (nla_type(attr) != NFTA_LIST_ELEM) @@ -4184,6 +4187,12 @@ static int nft_set_desc_concat(struct nf return err; }
+ for (i = 0; i < desc->field_count; i++) + num_regs += DIV_ROUND_UP(desc->field_len[i], sizeof(u32)); + + if (num_regs > NFT_REG32_COUNT) + return -E2BIG; + return 0; }