From ce0d9f04699706843e8a494d12cf6c7663d478c7 Mon Sep 17 00:00:00 2001 From: Richard Guy Briggs Date: Wed, 20 Nov 2013 14:01:53 -0500 Subject: audit: refactor audit_receive_msg() to clarify AUDIT_*_RULE* cases audit_receive_msg() needlessly contained a fallthrough case that called audit_receive_filter(), containing no common code between the cases. Separate them to make the logic clearer. Refactor AUDIT_LIST_RULES, AUDIT_ADD_RULE, AUDIT_DEL_RULE cases to create audit_rule_change(), audit_list_rules_send() functions. This should not functionally change the logic. Signed-off-by: Richard Guy Briggs Signed-off-by: Eric Paris --- include/linux/audit.h | 4 ++- kernel/audit.c | 7 ++--- kernel/auditfilter.c | 71 +++++++++++++++++++++++++++++---------------------- 3 files changed, 48 insertions(+), 34 deletions(-) diff --git a/include/linux/audit.h b/include/linux/audit.h index 1690f956bff5..697621975b8d 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -461,8 +461,10 @@ extern int audit_update_lsm_rules(void); /* Private API (for audit.c only) */ extern int audit_filter_user(int type); extern int audit_filter_type(int type); -extern int audit_receive_filter(int type, __u32 portid, int seq, +extern int audit_rule_change(int type, __u32 portid, int seq, void *data, size_t datasz); +extern int audit_list_rules_send(__u32 portid, int seq); + extern int audit_enabled; #else /* CONFIG_AUDIT */ static inline __printf(4, 5) diff --git a/kernel/audit.c b/kernel/audit.c index fdb8528ceca3..c460f33c2801 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -903,11 +903,12 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) audit_log_end(ab); return -EPERM; } - /* fallthrough */ - case AUDIT_LIST_RULES: - err = audit_receive_filter(msg_type, NETLINK_CB(skb).portid, + err = audit_rule_change(msg_type, NETLINK_CB(skb).portid, seq, data, nlmsg_len(nlh)); break; + case AUDIT_LIST_RULES: + err = audit_list_rules_send(NETLINK_CB(skb).portid, seq); + break; case AUDIT_TRIM: audit_trim_trees(); audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index d085cfbe416e..6cc8240b7aaf 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -1023,47 +1023,20 @@ static void audit_log_rule_change(char *action, struct audit_krule *rule, int re } /** - * audit_receive_filter - apply all rules to the specified message type + * audit_rule_change - apply all rules to the specified message type * @type: audit message type * @portid: target port id for netlink audit messages * @seq: netlink audit message sequence (serial) number * @data: payload data * @datasz: size of payload data */ -int audit_receive_filter(int type, __u32 portid, int seq, void *data, - size_t datasz) +int audit_rule_change(int type, __u32 portid, int seq, void *data, + size_t datasz) { - struct task_struct *tsk; - struct audit_netlink_list *dest; int err = 0; struct audit_entry *entry; switch (type) { - case AUDIT_LIST_RULES: - /* We can't just spew out the rules here because we might fill - * the available socket buffer space and deadlock waiting for - * auditctl to read from it... which isn't ever going to - * happen if we're actually running in the context of auditctl - * trying to _send_ the stuff */ - - dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL); - if (!dest) - return -ENOMEM; - dest->portid = portid; - dest->pid = task_pid_vnr(current); - skb_queue_head_init(&dest->q); - - mutex_lock(&audit_filter_mutex); - audit_list_rules(portid, seq, &dest->q); - mutex_unlock(&audit_filter_mutex); - - tsk = kthread_run(audit_send_list, dest, "audit_send_list"); - if (IS_ERR(tsk)) { - skb_queue_purge(&dest->q); - kfree(dest); - err = PTR_ERR(tsk); - } - break; case AUDIT_ADD_RULE: entry = audit_data_to_entry(data, datasz); if (IS_ERR(entry)) @@ -1090,6 +1063,44 @@ int audit_receive_filter(int type, __u32 portid, int seq, void *data, return err; } +/** + * audit_list_rules_send - list the audit rules + * @portid: target portid for netlink audit messages + * @seq: netlink audit message sequence (serial) number + */ +int audit_list_rules_send(__u32 portid, int seq) +{ + struct task_struct *tsk; + struct audit_netlink_list *dest; + int err = 0; + + /* We can't just spew out the rules here because we might fill + * the available socket buffer space and deadlock waiting for + * auditctl to read from it... which isn't ever going to + * happen if we're actually running in the context of auditctl + * trying to _send_ the stuff */ + + dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL); + if (!dest) + return -ENOMEM; + dest->portid = portid; + dest->pid = task_pid_vnr(current); + skb_queue_head_init(&dest->q); + + mutex_lock(&audit_filter_mutex); + audit_list_rules(portid, seq, &dest->q); + mutex_unlock(&audit_filter_mutex); + + tsk = kthread_run(audit_send_list, dest, "audit_send_list"); + if (IS_ERR(tsk)) { + skb_queue_purge(&dest->q); + kfree(dest); + err = PTR_ERR(tsk); + } + + return err; +} + int audit_comparator(u32 left, u32 op, u32 right) { switch (op) { -- cgit