3.16.83-rc1 review patch. If anyone has any objections, please let me know.
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From: Pablo Neira Ayuso pablo@netfilter.org
commit 71df14b0ce094be46d105b5a3ededd83b8e779a0 upstream.
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 pablo@netfilter.org [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- net/netfilter/nft_bitwise.c | 19 ++++++++++++++----- net/netfilter/nft_cmp.c | 12 ++++++++++-- 2 files changed, 24 insertions(+), 7 deletions(-)
--- a/net/netfilter/nft_bitwise.c +++ b/net/netfilter/nft_bitwise.c @@ -86,16 +86,25 @@ static int nft_bitwise_init(const struct err = nft_data_init(NULL, &priv->mask, &d1, tb[NFTA_BITWISE_MASK]); if (err < 0) return err; - if (d1.len != priv->len) - return -EINVAL; + if (d1.len != priv->len) { + err = -EINVAL; + goto err1; + }
err = nft_data_init(NULL, &priv->xor, &d2, tb[NFTA_BITWISE_XOR]); if (err < 0) - return err; - if (d2.len != priv->len) - return -EINVAL; + goto err1; + if (d2.len != priv->len) { + err = -EINVAL; + goto err2; + }
return 0; +err2: + nft_data_uninit(&priv->xor, d2.type); +err1: + nft_data_uninit(&priv->mask, d1.type); + return err; }
static int nft_bitwise_dump(struct sk_buff *skb, const struct nft_expr *expr) --- a/net/netfilter/nft_cmp.c +++ b/net/netfilter/nft_cmp.c @@ -201,10 +201,18 @@ nft_cmp_select_ops(const struct nft_ctx 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); }
static struct nft_expr_type nft_cmp_type __read_mostly = {