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@xxxxxxxxx>
---
v2: use XT_STANDARD/ERROR defines.
net/netfilter/nft_compat.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/net/netfilter/nft_compat.c b/net/netfilter/nft_compat.c
index 8d1ff654e5af..32535eea51b2 100644
--- a/net/netfilter/nft_compat.c
+++ b/net/netfilter/nft_compat.c
@@ -832,10 +832,18 @@ nft_target_select_ops(const struct nft_ctx *ctx,
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;
}
@@ -844,6 +852,11 @@ nft_target_select_ops(const struct nft_ctx *ctx,
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;
--
2.16.4
--
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