From: Florian Westphal fw@strlen.de

commit 18bbc3213383a82b05383827f4b1b882e3f0a5a5 upstream.

TPROXY is only allowed from prerouting, but nft_tproxy doesn't check this. This fixes a crash (null dereference) when using tproxy from e.g. output.

Fixes: 4ed8eb6570a4 ("netfilter: nf_tables: Add native tproxy support") Reported-by: Shell Chen xierch@gmail.com Signed-off-by: Florian Westphal fw@strlen.de Signed-off-by: Qingfang DENG dqfext@gmail.com --- net/netfilter/nft_tproxy.c | 8 ++++++++ 1 file changed, 8 insertions(+)

--- a/net/netfilter/nft_tproxy.c +++ b/net/netfilter/nft_tproxy.c @@ -312,6 +312,13 @@ static int nft_tproxy_dump(struct sk_buf return 0; }

+static int nft_tproxy_validate(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nft_data **data) +{ + return nft_chain_validate_hooks(ctx->chain, 1 << NF_INET_PRE_ROUTING); +} + static struct nft_expr_type nft_tproxy_type; static const struct nft_expr_ops nft_tproxy_ops = { .type = &nft_tproxy_type, @@ -320,6 +327,7 @@ static const struct nft_expr_ops nft_tpr .init = nft_tproxy_init, .destroy = nft_tproxy_destroy, .dump = nft_tproxy_dump, + .validate = nft_tproxy_validate, };

static struct nft_expr_type nft_tproxy_type __read_mostly = {