From c4dad0aab3fca0c1f0baa4cc84b6ec91b7ebf426 Mon Sep 17 00:00:00 2001 From: Richard Guy Briggs Date: Wed, 22 Apr 2020 17:39:28 -0400 Subject: [PATCH] audit: tidy and extend netfilter_cfg x_tables NETFILTER_CFG record generation was inconsistent for x_tables and ebtables configuration changes. The call was needlessly messy and there were supporting records missing at times while they were produced when not requested. Simplify the logging call into a new audit_log_nfcfg call. Honour the audit_enabled setting while more consistently recording information including supporting records by tidying up dummy checks. Add an op= field that indicates the operation being performed (register or replace). Here is the enhanced sample record: type=NETFILTER_CFG msg=audit(1580905834.919:82970): table=filter family=2 entries=83 op=replace Generate audit NETFILTER_CFG records on ebtables table registration. Previously this was being done for x_tables registration and replacement operations and ebtables table replacement only. See: https://github.com/linux-audit/audit-kernel/issues/25 See: https://github.com/linux-audit/audit-kernel/issues/35 See: https://github.com/linux-audit/audit-kernel/issues/43 Signed-off-by: Richard Guy Briggs Signed-off-by: Paul Moore --- include/linux/audit.h | 21 +++++++++++++++++++++ kernel/auditsc.c | 24 ++++++++++++++++++++++++ net/bridge/netfilter/ebtables.c | 12 ++++-------- net/netfilter/x_tables.c | 12 +++--------- 4 files changed, 52 insertions(+), 17 deletions(-) diff --git a/include/linux/audit.h b/include/linux/audit.h index f9ceae57ca8d..5c7f07a9776d 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -94,6 +94,11 @@ struct audit_ntp_data { struct audit_ntp_data {}; #endif +enum audit_nfcfgop { + AUDIT_XT_OP_REGISTER, + AUDIT_XT_OP_REPLACE, +}; + extern int is_audit_feature_set(int which); extern int __init audit_register_class(int class, unsigned *list); @@ -379,6 +384,8 @@ extern void __audit_log_kern_module(char *name); extern void __audit_fanotify(unsigned int response); extern void __audit_tk_injoffset(struct timespec64 offset); extern void __audit_ntp_log(const struct audit_ntp_data *ad); +extern void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries, + enum audit_nfcfgop op); static inline void audit_ipc_obj(struct kern_ipc_perm *ipcp) { @@ -514,6 +521,14 @@ static inline void audit_ntp_log(const struct audit_ntp_data *ad) __audit_ntp_log(ad); } +static inline void audit_log_nfcfg(const char *name, u8 af, + unsigned int nentries, + enum audit_nfcfgop op) +{ + if (audit_enabled) + __audit_log_nfcfg(name, af, nentries, op); +} + extern int audit_n_rules; extern int audit_signals; #else /* CONFIG_AUDITSYSCALL */ @@ -646,6 +661,12 @@ static inline void audit_ntp_log(const struct audit_ntp_data *ad) static inline void audit_ptrace(struct task_struct *t) { } + +static inline void audit_log_nfcfg(const char *name, u8 af, + unsigned int nentries, + enum audit_nfcfgop op) +{ } + #define audit_n_rules 0 #define audit_signals 0 #endif /* CONFIG_AUDITSYSCALL */ diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 814406a35db1..705beac0ce29 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -130,6 +130,16 @@ struct audit_tree_refs { struct audit_chunk *c[31]; }; +struct audit_nfcfgop_tab { + enum audit_nfcfgop op; + const char *s; +}; + +const struct audit_nfcfgop_tab audit_nfcfgs[] = { + { AUDIT_XT_OP_REGISTER, "register" }, + { AUDIT_XT_OP_REPLACE, "replace" }, +}; + static int audit_match_perm(struct audit_context *ctx, int mask) { unsigned n; @@ -2542,6 +2552,20 @@ void __audit_ntp_log(const struct audit_ntp_data *ad) audit_log_ntp_val(ad, "adjust", AUDIT_NTP_ADJUST); } +void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries, + enum audit_nfcfgop op) +{ + struct audit_buffer *ab; + + ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_NETFILTER_CFG); + if (!ab) + return; + audit_log_format(ab, "table=%s family=%u entries=%u op=%s", + name, af, nentries, audit_nfcfgs[op].s); + audit_log_end(ab); +} +EXPORT_SYMBOL_GPL(__audit_log_nfcfg); + static void audit_log_task(struct audit_buffer *ab) { kuid_t auid, uid; diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c index 78db58c7aec2..0a148e68b6e1 100644 --- a/net/bridge/netfilter/ebtables.c +++ b/net/bridge/netfilter/ebtables.c @@ -1046,14 +1046,8 @@ static int do_replace_finish(struct net *net, struct ebt_replace *repl, vfree(table); vfree(counterstmp); -#ifdef CONFIG_AUDIT - if (audit_enabled) { - audit_log(audit_context(), GFP_KERNEL, - AUDIT_NETFILTER_CFG, - "table=%s family=%u entries=%u", - repl->name, AF_BRIDGE, repl->nentries); - } -#endif + audit_log_nfcfg(repl->name, AF_BRIDGE, repl->nentries, + AUDIT_XT_OP_REPLACE); return ret; free_unlock: @@ -1223,6 +1217,8 @@ int ebt_register_table(struct net *net, const struct ebt_table *input_table, *res = NULL; } + audit_log_nfcfg(repl->name, AF_BRIDGE, repl->nentries, + AUDIT_XT_OP_REGISTER); return ret; free_unlock: mutex_unlock(&ebt_mutex); diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index cd2b034eef59..8f8c5dbf603d 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -1408,15 +1408,9 @@ xt_replace_table(struct xt_table *table, } } -#ifdef CONFIG_AUDIT - if (audit_enabled) { - audit_log(audit_context(), GFP_KERNEL, - AUDIT_NETFILTER_CFG, - "table=%s family=%u entries=%u", - table->name, table->af, private->number); - } -#endif - + audit_log_nfcfg(table->name, table->af, private->number, + !private->number ? AUDIT_XT_OP_REGISTER : + AUDIT_XT_OP_REPLACE); return private; } EXPORT_SYMBOL_GPL(xt_replace_table); -- GitLab