netfilter: nf_tables: Audit log setelem reset

Since set element reset is not integrated into nf_tables' transaction
logic, an explicit log call is needed, similar to NFT_MSG_GETOBJ_RESET
handling.

For the sake of simplicity, catchall element reset will always generate
a dedicated log entry. This relieves nf_tables_dump_set() from having to
adjust the logged element count depending on whether a catchall element
was found or not.

Fixes: 079cd633219d7 ("netfilter: nf_tables: Introduce NFT_MSG_GETSETELEM_RESET")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 6a3a9e1..192bf03 100644 (file)
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -117,6 +117,7 @@ enum audit_nfcfgop {
        AUDIT_NFT_OP_OBJ_RESET,
        AUDIT_NFT_OP_FLOWTABLE_REGISTER,
        AUDIT_NFT_OP_FLOWTABLE_UNREGISTER,
+       AUDIT_NFT_OP_SETELEM_RESET,
        AUDIT_NFT_OP_INVALID,
 };
 

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index addeed3..38481e3 100644 (file)
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -143,6 +143,7 @@ static const struct audit_nfcfgop_tab audit_nfcfgs[] = {
        { AUDIT_NFT_OP_OBJ_RESET,               "nft_reset_obj"            },
        { AUDIT_NFT_OP_FLOWTABLE_REGISTER,      "nft_register_flowtable"   },
        { AUDIT_NFT_OP_FLOWTABLE_UNREGISTER,    "nft_unregister_flowtable" },
+       { AUDIT_NFT_OP_SETELEM_RESET,           "nft_reset_setelem"        },
        { AUDIT_NFT_OP_INVALID,                 "nft_invalid"              },
 };
 

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 41b826d..361e98e 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -102,6 +102,7 @@ static const u8 nft2audit_op[NFT_MSG_MAX] = { // enum nf_tables_msg_types
        [NFT_MSG_NEWFLOWTABLE]  = AUDIT_NFT_OP_FLOWTABLE_REGISTER,
        [NFT_MSG_GETFLOWTABLE]  = AUDIT_NFT_OP_INVALID,
        [NFT_MSG_DELFLOWTABLE]  = AUDIT_NFT_OP_FLOWTABLE_UNREGISTER,
+       [NFT_MSG_GETSETELEM_RESET] = AUDIT_NFT_OP_SETELEM_RESET,
 };
 
 static void nft_validate_state_update(struct nft_table *table, u8 new_validate_state)
@@ -5624,13 +5625,25 @@ static int nf_tables_dump_setelem(const struct nft_ctx *ctx,
        return nf_tables_fill_setelem(args->skb, set, elem, args->reset);
 }
 
+static void audit_log_nft_set_reset(const struct nft_table *table,
+                                   unsigned int base_seq,
+                                   unsigned int nentries)
+{
+       char *buf = kasprintf(GFP_ATOMIC, "%s:%u", table->name, base_seq);
+
+       audit_log_nfcfg(buf, table->family, nentries,
+                       AUDIT_NFT_OP_SETELEM_RESET, GFP_ATOMIC);
+       kfree(buf);
+}
+
 struct nft_set_dump_ctx {
        const struct nft_set    *set;
        struct nft_ctx          ctx;
 };
 
 static int nft_set_catchall_dump(struct net *net, struct sk_buff *skb,
-                                const struct nft_set *set, bool reset)
+                                const struct nft_set *set, bool reset,
+                                unsigned int base_seq)
 {
        struct nft_set_elem_catchall *catchall;
        u8 genmask = nft_genmask_cur(net);
@@ -5646,6 +5659,8 @@ static int nft_set_catchall_dump(struct net *net, struct sk_buff *skb,
 
                elem.priv = catchall->elem;
                ret = nf_tables_fill_setelem(skb, set, &elem, reset);
+               if (reset && !ret)
+                       audit_log_nft_set_reset(set->table, base_seq, 1);
                break;
        }
 
@@ -5725,12 +5740,17 @@ static int nf_tables_dump_set(struct sk_buff *skb, struct netlink_callback *cb)
        set->ops->walk(&dump_ctx->ctx, set, &args.iter);
 
        if (!args.iter.err && args.iter.count == cb->args[0])
-               args.iter.err = nft_set_catchall_dump(net, skb, set, reset);
+               args.iter.err = nft_set_catchall_dump(net, skb, set,
+                                                     reset, cb->seq);
        rcu_read_unlock();
 
        nla_nest_end(skb, nest);
        nlmsg_end(skb, nlh);
 
+       if (reset && args.iter.count > args.iter.skip)
+               audit_log_nft_set_reset(table, cb->seq,
+                                       args.iter.count - args.iter.skip);
+
        if (args.iter.err && args.iter.err != -EMSGSIZE)
                return args.iter.err;
        if (args.iter.count == cb->args[0])
@@ -5955,13 +5975,13 @@ static int nf_tables_getsetelem(struct sk_buff *skb,
        struct netlink_ext_ack *extack = info->extack;
        u8 genmask = nft_genmask_cur(info->net);
        u8 family = info->nfmsg->nfgen_family;
+       int rem, err = 0, nelems = 0;
        struct net *net = info->net;
        struct nft_table *table;
        struct nft_set *set;
        struct nlattr *attr;
        struct nft_ctx ctx;
        bool reset = false;
-       int rem, err = 0;
 
        table = nft_table_lookup(net, nla[NFTA_SET_ELEM_LIST_TABLE], family,
                                 genmask, 0);
@@ -6004,8 +6024,13 @@ static int nf_tables_getsetelem(struct sk_buff *skb,
                        NL_SET_BAD_ATTR(extack, attr);
                        break;
                }
+               nelems++;
        }
 
+       if (reset)
+               audit_log_nft_set_reset(table, nft_pernet(net)->base_seq,
+                                       nelems);
+
        return err;
 }