netfilter: nf_tables: avoid BUG_ON usage

[ Upstream commit fa5950e498e7face21a1761f327e6c1152f778c3 ]

None of these spots really needs to crash the kernel.
In one two cases we can jsut report error to userspace, in the other
cases we can just use WARN_ON (and leak memory instead).

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 24fddf0..289d079 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1031,7 +1031,8 @@ static int nf_tables_deltable(struct net *net, struct sock *nlsk,
 
 static void nf_tables_table_destroy(struct nft_ctx *ctx)
 {
-       BUG_ON(ctx->table->use > 0);
+       if (WARN_ON(ctx->table->use > 0))
+               return;
 
        rhltable_destroy(&ctx->table->chains_ht);
        kfree(ctx->table->name);
@@ -1446,7 +1447,8 @@ static void nf_tables_chain_destroy(struct nft_ctx *ctx)
 {
        struct nft_chain *chain = ctx->chain;
 
-       BUG_ON(chain->use > 0);
+       if (WARN_ON(chain->use > 0))
+               return;
 
        /* no concurrent access possible anymore */
        nf_tables_chain_free_chain_rules(chain);
@@ -7253,7 +7255,8 @@ int __nft_release_basechain(struct nft_ctx *ctx)
 {
        struct nft_rule *rule, *nr;
 
-       BUG_ON(!nft_is_base_chain(ctx->chain));
+       if (WARN_ON(!nft_is_base_chain(ctx->chain)))
+               return 0;
 
        nf_tables_unregister_hook(ctx->net, ctx->chain->table, ctx->chain);
        list_for_each_entry_safe(rule, nr, &ctx->chain->rules, list) {

diff --git a/net/netfilter/nft_cmp.c b/net/netfilter/nft_cmp.c
index fa90a84..79d48c1 100644 (file)
--- a/net/netfilter/nft_cmp.c
+++ b/net/netfilter/nft_cmp.c
@@ -79,7 +79,8 @@ static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
 
        err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc,
                            tb[NFTA_CMP_DATA]);
-       BUG_ON(err < 0);
+       if (err < 0)
+               return err;
 
        priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
        err = nft_validate_register_load(priv->sreg, desc.len);
@@ -129,7 +130,8 @@ static int nft_cmp_fast_init(const struct nft_ctx *ctx,
 
        err = nft_data_init(NULL, &data, sizeof(data), &desc,
                            tb[NFTA_CMP_DATA]);
-       BUG_ON(err < 0);
+       if (err < 0)
+               return err;
 
        priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
        err = nft_validate_register_load(priv->sreg, desc.len);

diff --git a/net/netfilter/nft_reject.c b/net/netfilter/nft_reject.c
index 29f5bd2..b48e58c 100644 (file)
--- a/net/netfilter/nft_reject.c
+++ b/net/netfilter/nft_reject.c
@@ -94,7 +94,8 @@ static u8 icmp_code_v4[NFT_REJECT_ICMPX_MAX + 1] = {
 
 int nft_reject_icmp_code(u8 code)
 {
-       BUG_ON(code > NFT_REJECT_ICMPX_MAX);
+       if (WARN_ON_ONCE(code > NFT_REJECT_ICMPX_MAX))
+               return ICMP_NET_UNREACH;
 
        return icmp_code_v4[code];
 }
@@ -111,7 +112,8 @@ static u8 icmp_code_v6[NFT_REJECT_ICMPX_MAX + 1] = {
 
 int nft_reject_icmpv6_code(u8 code)
 {
-       BUG_ON(code > NFT_REJECT_ICMPX_MAX);
+       if (WARN_ON_ONCE(code > NFT_REJECT_ICMPX_MAX))
+               return ICMPV6_NOROUTE;
 
        return icmp_code_v6[code];
 }