From 71df14b0ce094be46d105b5a3ededd83b8e779a0 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 15 May 2017 11:17:29 +0100 Subject: netfilter: nf_tables: missing sanitization in data from userspace Do not assume userspace always sends us NFT_DATA_VALUE for bitwise and cmp expressions. Although NFT_DATA_VERDICT does not make any sense, it is still possible to handcraft a netlink message using this incorrect data type. Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_cmp.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'net/netfilter/nft_cmp.c') diff --git a/net/netfilter/nft_cmp.c b/net/netfilter/nft_cmp.c index 2b96effeadc1..8c9d0fb19118 100644 --- a/net/netfilter/nft_cmp.c +++ b/net/netfilter/nft_cmp.c @@ -201,10 +201,18 @@ nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[]) if (err < 0) return ERR_PTR(err); + if (desc.type != NFT_DATA_VALUE) { + err = -EINVAL; + goto err1; + } + if (desc.len <= sizeof(u32) && op == NFT_CMP_EQ) return &nft_cmp_fast_ops; - else - return &nft_cmp_ops; + + return &nft_cmp_ops; +err1: + nft_data_uninit(&data, desc.type); + return ERR_PTR(-EINVAL); } struct nft_expr_type nft_cmp_type __read_mostly = { -- cgit v1.2.3