Same conversion as for table names, use NFT_NAME_MAXLEN as upper
boundary as well.

Signed-off-by: Phil Sutter <[email protected]>
---
Changes since v1:
- Introduce NFT_NAME_MAXLEN as an upper boundary to restrict overly long
  names but still allow to use e.g. domain names.
- Adjust commit messages accordingly.

Changes since v2:
- Adjust commit summary - length is not really unlimited.
- Don't drop NFT_CHAIN_MAXNAMELEN macro since it's UAPI.
- Keep using NFT_CHAIN_MAXNAMELEN in netlink policies to reduce patch
  size.
- Be more pedantic when checking for existence of
  info->verdict->chain->name.
---
 include/net/netfilter/nf_tables.h        |  4 ++--
 include/uapi/linux/netfilter/nf_tables.h |  2 +-
 net/netfilter/nf_tables_api.c            | 34 ++++++++++++++++++++++++--------
 net/netfilter/nf_tables_trace.c          | 27 +++++++++++++++++++++++--
 4 files changed, 54 insertions(+), 13 deletions(-)

diff --git a/include/net/netfilter/nf_tables.h 
b/include/net/netfilter/nf_tables.h
index 05ecf78ec0787..be1610162ee02 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -859,7 +859,7 @@ struct nft_chain {
        u16                             level;
        u8                              flags:6,
                                        genmask:2;
-       char                            name[NFT_CHAIN_MAXNAMELEN];
+       char                            *name;
 };
 
 enum nft_chain_type {
@@ -1272,7 +1272,7 @@ struct nft_trans_set {
 
 struct nft_trans_chain {
        bool                            update;
-       char                            name[NFT_CHAIN_MAXNAMELEN];
+       char                            *name;
        struct nft_stats __percpu       *stats;
        u8                              policy;
 };
diff --git a/include/uapi/linux/netfilter/nf_tables.h 
b/include/uapi/linux/netfilter/nf_tables.h
index f796da401672b..6b586f43bd53a 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -3,7 +3,7 @@
 
 #define NFT_NAME_MAXLEN                256
 #define NFT_TABLE_MAXNAMELEN   NFT_NAME_MAXLEN
-#define NFT_CHAIN_MAXNAMELEN   32
+#define NFT_CHAIN_MAXNAMELEN   NFT_NAME_MAXLEN
 #define NFT_SET_MAXNAMELEN     32
 #define NFT_OBJ_MAXNAMELEN     32
 #define NFT_USERDATA_MAXLEN    256
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index dd824def0a182..55368ad7b9e7a 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1248,8 +1248,10 @@ static void nf_tables_chain_destroy(struct nft_chain 
*chain)
                free_percpu(basechain->stats);
                if (basechain->ops[0].dev != NULL)
                        dev_put(basechain->ops[0].dev);
+               kfree(chain->name);
                kfree(basechain);
        } else {
+               kfree(chain->name);
                kfree(chain);
        }
 }
@@ -1474,8 +1476,13 @@ static int nf_tables_newchain(struct net *net, struct 
sock *nlsk,
                        nft_trans_chain_policy(trans) = -1;
 
                if (nla[NFTA_CHAIN_HANDLE] && name) {
-                       nla_strlcpy(nft_trans_chain_name(trans), name,
-                                   NFT_CHAIN_MAXNAMELEN);
+                       nft_trans_chain_name(trans) =
+                               nla_strdup(name, GFP_KERNEL);
+                       if (!nft_trans_chain_name(trans)) {
+                               kfree(trans);
+                               free_percpu(stats);
+                               return -ENOMEM;
+                       }
                }
                list_add_tail(&trans->list, &net->nft.commit_list);
                return 0;
@@ -1549,7 +1556,11 @@ static int nf_tables_newchain(struct net *net, struct 
sock *nlsk,
        INIT_LIST_HEAD(&chain->rules);
        chain->handle = nf_tables_alloc_handle(table);
        chain->table = table;
-       nla_strlcpy(chain->name, name, NFT_CHAIN_MAXNAMELEN);
+       chain->name = nla_strdup(name, GFP_KERNEL);
+       if (!chain->name) {
+               err = -ENOMEM;
+               goto err1;
+       }
 
        err = nf_tables_register_hooks(net, table, chain, afi->nops);
        if (err < 0)
@@ -1984,7 +1995,7 @@ static void nf_tables_rule_notify(const struct nft_ctx 
*ctx,
 
 struct nft_rule_dump_ctx {
        char *table;
-       char chain[NFT_CHAIN_MAXNAMELEN];
+       char *chain;
 };
 
 static int nf_tables_dump_rules(struct sk_buff *skb,
@@ -2052,6 +2063,7 @@ static int nf_tables_dump_rules_done(struct 
netlink_callback *cb)
 
        if (ctx) {
                kfree(ctx->table);
+               kfree(ctx->chain);
                kfree(ctx);
        }
        return 0;
@@ -2093,9 +2105,15 @@ static int nf_tables_getrule(struct net *net, struct 
sock *nlsk,
                                        return -ENOMEM;
                                }
                        }
-                       if (nla[NFTA_RULE_CHAIN])
-                               nla_strlcpy(ctx->chain, nla[NFTA_RULE_CHAIN],
-                                           sizeof(ctx->chain));
+                       if (nla[NFTA_RULE_CHAIN]) {
+                               ctx->chain = nla_strdup(nla[NFTA_RULE_CHAIN],
+                                                       GFP_KERNEL);
+                               if (!ctx->chain) {
+                                       kfree(ctx->table);
+                                       kfree(ctx);
+                                       return -ENOMEM;
+                               }
+                       }
                        c.data = ctx;
                }
 
@@ -4865,7 +4883,7 @@ static void nft_chain_commit_update(struct nft_trans 
*trans)
 {
        struct nft_base_chain *basechain;
 
-       if (nft_trans_chain_name(trans)[0])
+       if (nft_trans_chain_name(trans))
                strcpy(trans->ctx.chain->name, nft_trans_chain_name(trans));
 
        if (!nft_is_base_chain(trans->ctx.chain))
diff --git a/net/netfilter/nf_tables_trace.c b/net/netfilter/nf_tables_trace.c
index 62787d985e9d3..e1dc527a493b8 100644
--- a/net/netfilter/nf_tables_trace.c
+++ b/net/netfilter/nf_tables_trace.c
@@ -162,6 +162,27 @@ static int nf_trace_fill_rule_info(struct sk_buff *nlskb,
                            NFTA_TRACE_PAD);
 }
 
+static bool nft_trace_have_verdict_chain(struct nft_traceinfo *info)
+{
+       switch (info->type) {
+       case NFT_TRACETYPE_RETURN:
+       case NFT_TRACETYPE_RULE:
+               break;
+       default:
+               return false;
+       }
+
+       switch (info->verdict->code) {
+       case NFT_JUMP:
+       case NFT_GOTO:
+               break;
+       default:
+               return false;
+       }
+
+       return true;
+}
+
 void nft_trace_notify(struct nft_traceinfo *info)
 {
        const struct nft_pktinfo *pkt = info->pkt;
@@ -176,12 +197,11 @@ void nft_trace_notify(struct nft_traceinfo *info)
 
        size = nlmsg_total_size(sizeof(struct nfgenmsg)) +
                nla_total_size(strlen(info->chain->table->name)) +
-               nla_total_size(NFT_CHAIN_MAXNAMELEN) +
+               nla_total_size(strlen(info->chain->name)) +
                nla_total_size_64bit(sizeof(__be64)) +  /* rule handle */
                nla_total_size(sizeof(__be32)) +        /* trace type */
                nla_total_size(0) +                     /* VERDICT, nested */
                        nla_total_size(sizeof(u32)) +   /* verdict code */
-                       nla_total_size(NFT_CHAIN_MAXNAMELEN) + /* jump target */
                nla_total_size(sizeof(u32)) +           /* id */
                nla_total_size(NFT_TRACETYPE_LL_HSIZE) +
                nla_total_size(NFT_TRACETYPE_NETWORK_HSIZE) +
@@ -194,6 +214,9 @@ void nft_trace_notify(struct nft_traceinfo *info)
                nla_total_size(sizeof(u32)) +           /* nfproto */
                nla_total_size(sizeof(u32));            /* policy */
 
+       if (nft_trace_have_verdict_chain(info))
+               size += nla_total_size(strlen(info->verdict->chain->name)); /* 
jump target */
+
        skb = nlmsg_new(size, GFP_ATOMIC);
        if (!skb)
                return;
-- 
2.13.1

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