[PATCH openEuler-5.10-LTS 093/151] audit: log nftables configuration change events once per table

From: Richard Guy Briggs rgb@redhat.com

stable inclusion from stable-v5.10.138 commit e2a49009ba037e3710fd1d6a285d688415ddcbe1 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I60QFD

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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[ Upstream commit c520292f29b8047285bcfbc2322fa2a9bf02521a ]

Reduce logging of nftables events to a level similar to iptables. Restore the table field to list the table, adding the generation.

Indicate the op as the most significant operation in the event.

A couple of sample events:

type=PROCTITLE msg=audit(2021-03-18 09:30:49.801:143) : proctitle=/usr/bin/python3 -s /usr/sbin/firewalld --nofork --nopid type=SYSCALL msg=audit(2021-03-18 09:30:49.801:143) : arch=x86_64 syscall=sendmsg success=yes exit=172 a0=0x6 a1=0x7ffdcfcbe650 a2=0x0 a3=0x7ffdcfcbd52c items=0 ppid=1 pid=367 auid=unset uid=root gid=root euid=root suid=root fsuid=root egid=roo t sgid=root fsgid=root tty=(none) ses=unset comm=firewalld exe=/usr/bin/python3.9 subj=system_u:system_r:firewalld_t:s0 key=(null) type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.801:143) : table=firewalld:2 family=ipv6 entries=1 op=nft_register_table pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.801:143) : table=firewalld:2 family=ipv4 entries=1 op=nft_register_table pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.801:143) : table=firewalld:2 family=inet entries=1 op=nft_register_table pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld

type=PROCTITLE msg=audit(2021-03-18 09:30:49.839:144) : proctitle=/usr/bin/python3 -s /usr/sbin/firewalld --nofork --nopid type=SYSCALL msg=audit(2021-03-18 09:30:49.839:144) : arch=x86_64 syscall=sendmsg success=yes exit=22792 a0=0x6 a1=0x7ffdcfcbe650 a2=0x0 a3=0x7ffdcfcbd52c items=0 ppid=1 pid=367 auid=unset uid=root gid=root euid=root suid=root fsuid=root egid=r oot sgid=root fsgid=root tty=(none) ses=unset comm=firewalld exe=/usr/bin/python3.9 subj=system_u:system_r:firewalld_t:s0 key=(null) type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.839:144) : table=firewalld:3 family=ipv6 entries=30 op=nft_register_chain pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.839:144) : table=firewalld:3 family=ipv4 entries=30 op=nft_register_chain pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.839:144) : table=firewalld:3 family=inet entries=165 op=nft_register_chain pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld

The issue was originally documented in https://github.com/linux-audit/audit-kernel/issues/124

Signed-off-by: Richard Guy Briggs rgb@redhat.com Acked-by: Paul Moore paul@paul-moore.com Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Reviewed-by: Wei Li liwei391@huawei.com --- net/netfilter/nf_tables_api.c | 186 +++++++++++++++++++--------------- 1 file changed, 103 insertions(+), 83 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index e200d70eb20d..990fccfec8be 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -66,6 +66,41 @@ static const struct rhashtable_params nft_objname_ht_params = { .automatic_shrinking = true, };

+struct nft_audit_data { + struct nft_table *table; + int entries; + int op; + struct list_head list; +}; + +static const u8 nft2audit_op[NFT_MSG_MAX] = { // enum nf_tables_msg_types + [NFT_MSG_NEWTABLE] = AUDIT_NFT_OP_TABLE_REGISTER, + [NFT_MSG_GETTABLE] = AUDIT_NFT_OP_INVALID, + [NFT_MSG_DELTABLE] = AUDIT_NFT_OP_TABLE_UNREGISTER, + [NFT_MSG_NEWCHAIN] = AUDIT_NFT_OP_CHAIN_REGISTER, + [NFT_MSG_GETCHAIN] = AUDIT_NFT_OP_INVALID, + [NFT_MSG_DELCHAIN] = AUDIT_NFT_OP_CHAIN_UNREGISTER, + [NFT_MSG_NEWRULE] = AUDIT_NFT_OP_RULE_REGISTER, + [NFT_MSG_GETRULE] = AUDIT_NFT_OP_INVALID, + [NFT_MSG_DELRULE] = AUDIT_NFT_OP_RULE_UNREGISTER, + [NFT_MSG_NEWSET] = AUDIT_NFT_OP_SET_REGISTER, + [NFT_MSG_GETSET] = AUDIT_NFT_OP_INVALID, + [NFT_MSG_DELSET] = AUDIT_NFT_OP_SET_UNREGISTER, + [NFT_MSG_NEWSETELEM] = AUDIT_NFT_OP_SETELEM_REGISTER, + [NFT_MSG_GETSETELEM] = AUDIT_NFT_OP_INVALID, + [NFT_MSG_DELSETELEM] = AUDIT_NFT_OP_SETELEM_UNREGISTER, + [NFT_MSG_NEWGEN] = AUDIT_NFT_OP_GEN_REGISTER, + [NFT_MSG_GETGEN] = AUDIT_NFT_OP_INVALID, + [NFT_MSG_TRACE] = AUDIT_NFT_OP_INVALID, + [NFT_MSG_NEWOBJ] = AUDIT_NFT_OP_OBJ_REGISTER, + [NFT_MSG_GETOBJ] = AUDIT_NFT_OP_INVALID, + [NFT_MSG_DELOBJ] = AUDIT_NFT_OP_OBJ_UNREGISTER, + [NFT_MSG_GETOBJ_RESET] = AUDIT_NFT_OP_OBJ_RESET, + [NFT_MSG_NEWFLOWTABLE] = AUDIT_NFT_OP_FLOWTABLE_REGISTER, + [NFT_MSG_GETFLOWTABLE] = AUDIT_NFT_OP_INVALID, + [NFT_MSG_DELFLOWTABLE] = AUDIT_NFT_OP_FLOWTABLE_UNREGISTER, +}; + static void nft_validate_state_update(struct net *net, u8 new_validate_state) { switch (net->nft.validate_state) { @@ -710,17 +745,6 @@ static void nf_tables_table_notify(const struct nft_ctx *ctx, int event) { struct sk_buff *skb; int err; - char *buf = kasprintf(GFP_KERNEL, "%s:%llu;?:0", - ctx->table->name, ctx->table->handle); - - audit_log_nfcfg(buf, - ctx->family, - ctx->table->use, - event == NFT_MSG_NEWTABLE ? - AUDIT_NFT_OP_TABLE_REGISTER : - AUDIT_NFT_OP_TABLE_UNREGISTER, - GFP_KERNEL); - kfree(buf);

if (!ctx->report && !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES)) @@ -1477,18 +1501,6 @@ static void nf_tables_chain_notify(const struct nft_ctx *ctx, int event) { struct sk_buff *skb; int err; - char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu", - ctx->table->name, ctx->table->handle, - ctx->chain->name, ctx->chain->handle); - - audit_log_nfcfg(buf, - ctx->family, - ctx->chain->use, - event == NFT_MSG_NEWCHAIN ? - AUDIT_NFT_OP_CHAIN_REGISTER : - AUDIT_NFT_OP_CHAIN_UNREGISTER, - GFP_KERNEL); - kfree(buf);

if (!ctx->report && !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES)) @@ -2844,18 +2856,6 @@ static void nf_tables_rule_notify(const struct nft_ctx *ctx, { struct sk_buff *skb; int err; - char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu", - ctx->table->name, ctx->table->handle, - ctx->chain->name, ctx->chain->handle); - - audit_log_nfcfg(buf, - ctx->family, - rule->handle, - event == NFT_MSG_NEWRULE ? - AUDIT_NFT_OP_RULE_REGISTER : - AUDIT_NFT_OP_RULE_UNREGISTER, - GFP_KERNEL); - kfree(buf);

if (!ctx->report && !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES)) @@ -3882,18 +3882,6 @@ static void nf_tables_set_notify(const struct nft_ctx *ctx, struct sk_buff *skb; u32 portid = ctx->portid; int err; - char *buf = kasprintf(gfp_flags, "%s:%llu;%s:%llu", - ctx->table->name, ctx->table->handle, - set->name, set->handle); - - audit_log_nfcfg(buf, - ctx->family, - set->field_count, - event == NFT_MSG_NEWSET ? - AUDIT_NFT_OP_SET_REGISTER : - AUDIT_NFT_OP_SET_UNREGISTER, - gfp_flags); - kfree(buf);

if (!ctx->report && !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES)) @@ -5035,18 +5023,6 @@ static void nf_tables_setelem_notify(const struct nft_ctx *ctx, u32 portid = ctx->portid; struct sk_buff *skb; int err; - char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu", - ctx->table->name, ctx->table->handle, - set->name, set->handle); - - audit_log_nfcfg(buf, - ctx->family, - set->handle, - event == NFT_MSG_NEWSETELEM ? - AUDIT_NFT_OP_SETELEM_REGISTER : - AUDIT_NFT_OP_SETELEM_UNREGISTER, - GFP_KERNEL); - kfree(buf);

if (!ctx->report && !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES)) return; @@ -6180,12 +6156,11 @@ static int nf_tables_dump_obj(struct sk_buff *skb, struct netlink_callback *cb) filter->type != NFT_OBJECT_UNSPEC && obj->ops->type->type != filter->type) goto cont; - if (reset) { char *buf = kasprintf(GFP_ATOMIC, - "%s:%llu;?:0", + "%s:%u", table->name, - table->handle); + net->nft.base_seq);

audit_log_nfcfg(buf, family, @@ -6306,8 +6281,8 @@ static int nf_tables_getobj(struct net *net, struct sock *nlsk, reset = true;

if (reset) { - char *buf = kasprintf(GFP_ATOMIC, "%s:%llu;?:0", - table->name, table->handle); + char *buf = kasprintf(GFP_ATOMIC, "%s:%u", + table->name, net->nft.base_seq);

audit_log_nfcfg(buf, family, @@ -6394,15 +6369,15 @@ void nft_obj_notify(struct net *net, const struct nft_table *table, { struct sk_buff *skb; int err; - char *buf = kasprintf(gfp, "%s:%llu;?:0", - table->name, table->handle); + char *buf = kasprintf(gfp, "%s:%u", + table->name, net->nft.base_seq);

audit_log_nfcfg(buf, family, obj->handle, event == NFT_MSG_NEWOBJ ? - AUDIT_NFT_OP_OBJ_REGISTER : - AUDIT_NFT_OP_OBJ_UNREGISTER, + AUDIT_NFT_OP_OBJ_REGISTER : + AUDIT_NFT_OP_OBJ_UNREGISTER, gfp); kfree(buf);

@@ -7220,18 +7195,6 @@ static void nf_tables_flowtable_notify(struct nft_ctx *ctx, { struct sk_buff *skb; int err; - char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu", - flowtable->table->name, flowtable->table->handle, - flowtable->name, flowtable->handle); - - audit_log_nfcfg(buf, - ctx->family, - flowtable->hooknum, - event == NFT_MSG_NEWFLOWTABLE ? - AUDIT_NFT_OP_FLOWTABLE_REGISTER : - AUDIT_NFT_OP_FLOWTABLE_UNREGISTER, - GFP_KERNEL); - kfree(buf);

if (!ctx->report && !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES)) @@ -7352,9 +7315,6 @@ static void nf_tables_gen_notify(struct net *net, struct sk_buff *skb, struct sk_buff *skb2; int err;

- audit_log_nfcfg("?:0;?:0", 0, net->nft.base_seq, - AUDIT_NFT_OP_GEN_REGISTER, GFP_KERNEL); - if (!nlmsg_report(nlh) && !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES)) return; @@ -7885,12 +7845,64 @@ static void nft_commit_notify(struct net *net, u32 portid) WARN_ON_ONCE(!list_empty(&net->nft.notify_list)); }

+static int nf_tables_commit_audit_alloc(struct list_head *adl, + struct nft_table *table) +{ + struct nft_audit_data *adp; + + list_for_each_entry(adp, adl, list) { + if (adp->table == table) + return 0; + } + adp = kzalloc(sizeof(*adp), GFP_KERNEL); + if (!adp) + return -ENOMEM; + adp->table = table; + list_add(&adp->list, adl); + return 0; +} + +static void nf_tables_commit_audit_collect(struct list_head *adl, + struct nft_table *table, u32 op) +{ + struct nft_audit_data *adp; + + list_for_each_entry(adp, adl, list) { + if (adp->table == table) + goto found; + } + WARN_ONCE("table=%s not expected in commit list", table->name); + return; +found: + adp->entries++; + if (!adp->op || adp->op > op) + adp->op = op; +} + +#define AUNFTABLENAMELEN (NFT_TABLE_MAXNAMELEN + 22) + +static void nf_tables_commit_audit_log(struct list_head *adl, u32 generation) +{ + struct nft_audit_data *adp, *adn; + char aubuf[AUNFTABLENAMELEN]; + + list_for_each_entry_safe(adp, adn, adl, list) { + snprintf(aubuf, AUNFTABLENAMELEN, "%s:%u", adp->table->name, + generation); + audit_log_nfcfg(aubuf, adp->table->family, adp->entries, + nft2audit_op[adp->op], GFP_KERNEL); + list_del(&adp->list); + kfree(adp); + } +} + static int nf_tables_commit(struct net *net, struct sk_buff *skb) { struct nft_trans *trans, *next; struct nft_trans_elem *te; struct nft_chain *chain; struct nft_table *table; + LIST_HEAD(adl); int err;

if (list_empty(&net->nft.commit_list)) { @@ -7910,6 +7922,11 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) list_for_each_entry_safe(trans, next, &net->nft.commit_list, list) { int ret;

+ ret = nf_tables_commit_audit_alloc(&adl, trans->ctx.table); + if (ret) { + nf_tables_commit_chain_prepare_cancel(net); + return ret; + } if (trans->msg_type == NFT_MSG_NEWRULE || trans->msg_type == NFT_MSG_DELRULE) { chain = trans->ctx.chain; @@ -7938,6 +7955,8 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) net->nft.gencursor = nft_gencursor_next(net);

list_for_each_entry_safe(trans, next, &net->nft.commit_list, list) { + nf_tables_commit_audit_collect(&adl, trans->ctx.table, + trans->msg_type); switch (trans->msg_type) { case NFT_MSG_NEWTABLE: if (nft_trans_table_update(trans)) { @@ -8092,6 +8111,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)

nft_commit_notify(net, NETLINK_CB(skb).portid); nf_tables_gen_notify(net, skb, NFT_MSG_NEWGEN); + nf_tables_commit_audit_log(&adl, net->nft.base_seq); nf_tables_commit_release(net);

return 0;