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authorPablo Neira Ayuso <pablo@netfilter.org>2016-06-11 12:20:27 +0800
committerPablo Neira Ayuso <pablo@netfilter.org>2016-06-15 12:17:23 +0200
commit8588ac097b49ce8802f11541d9cd6f6667badb34 (patch)
tree3b32986c8d5553fbb2a679b9a2e7fa57de79b8bd /net
parenta46844021f6182cca7b575295ba33a4734b1b9d9 (diff)
downloadlinux-8588ac097b49ce8802f11541d9cd6f6667badb34.tar.bz2
netfilter: nf_tables: reject loops from set element jump to chain
Liping Zhang says: "Users may add such a wrong nft rules successfully, which will cause an endless jump loop: # nft add rule filter test tcp dport vmap {1: jump test} This is because before we commit, the element in the current anonymous set is inactive, so osp->walk will skip this element and miss the validate check." To resolve this problem, this patch passes the generation mask to the walk function through the iter container structure depending on the code path: 1) If we're dumping the elements, then we have to check if the element is active in the current generation. Thus, we check for the current bit in the genmask. 2) If we're checking for loops, then we have to check if the element is active in the next generation, as we're in the middle of a transaction. Thus, we check for the next bit in the genmask. Based on original patch from Liping Zhang. Reported-by: Liping Zhang <liping.zhang@spreadtrum.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Tested-by: Liping Zhang <liping.zhang@spreadtrum.com>
Diffstat (limited to 'net')
-rw-r--r--net/netfilter/nf_tables_api.c15
-rw-r--r--net/netfilter/nft_hash.c3
-rw-r--r--net/netfilter/nft_rbtree.c3
3 files changed, 11 insertions, 10 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 492f6f8efdda..0fd69988f00b 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2951,6 +2951,7 @@ int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set,
goto bind;
}
+ iter.genmask = nft_genmask_next(ctx->net);
iter.skip = 0;
iter.count = 0;
iter.err = 0;
@@ -3192,12 +3193,13 @@ static int nf_tables_dump_set(struct sk_buff *skb, struct netlink_callback *cb)
if (nest == NULL)
goto nla_put_failure;
- args.cb = cb;
- args.skb = skb;
- args.iter.skip = cb->args[0];
- args.iter.count = 0;
- args.iter.err = 0;
- args.iter.fn = nf_tables_dump_setelem;
+ args.cb = cb;
+ args.skb = skb;
+ args.iter.genmask = nft_genmask_cur(ctx.net);
+ args.iter.skip = cb->args[0];
+ args.iter.count = 0;
+ args.iter.err = 0;
+ args.iter.fn = nf_tables_dump_setelem;
set->ops->walk(&ctx, set, &args.iter);
nla_nest_end(skb, nest);
@@ -4284,6 +4286,7 @@ static int nf_tables_check_loops(const struct nft_ctx *ctx,
binding->chain != chain)
continue;
+ iter.genmask = nft_genmask_next(ctx->net);
iter.skip = 0;
iter.count = 0;
iter.err = 0;
diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c
index 6fa016564f90..f39c53a159eb 100644
--- a/net/netfilter/nft_hash.c
+++ b/net/netfilter/nft_hash.c
@@ -189,7 +189,6 @@ static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
struct nft_hash_elem *he;
struct rhashtable_iter hti;
struct nft_set_elem elem;
- u8 genmask = nft_genmask_cur(read_pnet(&set->pnet));
int err;
err = rhashtable_walk_init(&priv->ht, &hti, GFP_KERNEL);
@@ -218,7 +217,7 @@ static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
goto cont;
if (nft_set_elem_expired(&he->ext))
goto cont;
- if (!nft_set_elem_active(&he->ext, genmask))
+ if (!nft_set_elem_active(&he->ext, iter->genmask))
goto cont;
elem.priv = he;
diff --git a/net/netfilter/nft_rbtree.c b/net/netfilter/nft_rbtree.c
index f762094af7c1..7201d57b5a93 100644
--- a/net/netfilter/nft_rbtree.c
+++ b/net/netfilter/nft_rbtree.c
@@ -211,7 +211,6 @@ static void nft_rbtree_walk(const struct nft_ctx *ctx,
struct nft_rbtree_elem *rbe;
struct nft_set_elem elem;
struct rb_node *node;
- u8 genmask = nft_genmask_cur(read_pnet(&set->pnet));
spin_lock_bh(&nft_rbtree_lock);
for (node = rb_first(&priv->root); node != NULL; node = rb_next(node)) {
@@ -219,7 +218,7 @@ static void nft_rbtree_walk(const struct nft_ctx *ctx,
if (iter->count < iter->skip)
goto cont;
- if (!nft_set_elem_active(&rbe->ext, genmask))
+ if (!nft_set_elem_active(&rbe->ext, iter->genmask))
goto cont;
elem.priv = rbe;