4.17-stable review patch. If anyone has any objections, please let me know.
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From: Florian Westphal fw@strlen.de
[ Upstream commit 21d5e078192d244df3d6049f9464fff2f72cfd68 ]
iptables-nft never requests these, but make this explicitly illegal. If it were quested, kernel could oops as ->eval is NULL, furthermore, the builtin targets have no owning module so its possible to rmmod eb/ip/ip6_tables module even if they would be loaded.
Signed-off-by: Florian Westphal fw@strlen.de Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netfilter/nft_compat.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
--- a/net/netfilter/nft_compat.c +++ b/net/netfilter/nft_compat.c @@ -825,10 +825,18 @@ nft_target_select_ops(const struct nft_c rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV])); family = ctx->family;
+ if (strcmp(tg_name, XT_ERROR_TARGET) == 0 || + strcmp(tg_name, XT_STANDARD_TARGET) == 0 || + strcmp(tg_name, "standard") == 0) + return ERR_PTR(-EINVAL); + /* Re-use the existing target if it's already loaded. */ list_for_each_entry(nft_target, &nft_target_list, head) { struct xt_target *target = nft_target->ops.data;
+ if (!target->target) + continue; + if (nft_target_cmp(target, tg_name, rev, family)) return &nft_target->ops; } @@ -837,6 +845,11 @@ nft_target_select_ops(const struct nft_c if (IS_ERR(target)) return ERR_PTR(-ENOENT);
+ if (!target->target) { + err = -EINVAL; + goto err; + } + if (target->targetsize > nla_len(tb[NFTA_TARGET_INFO])) { err = -EINVAL; goto err;