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AUDIT: Clean up user message filtering

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Don't look up the task by its pid and then use the syscall filtering
helper. Just implement our own filter helper which operates solely on
the information in the netlink_skb_parms. 

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
This commit is contained in:
David Woodhouse 2005-06-24 14:14:05 +01:00
parent 993e2d4106
commit 5bb289b5a0
3 changed files with 46 additions and 17 deletions
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5
include/linux/audit.h
View File

@ -205,6 +205,7 @@ struct audit_sig_info {
struct audit_buffer;
struct audit_context;
struct inode;
struct netlink_skb_parms;
#define AUDITSC_INVALID 0
#define AUDITSC_SUCCESS 1
@ -236,7 +237,7 @@ extern int audit_socketcall(int nargs, unsigned long *args);
extern int audit_sockaddr(int len, void *addr);
extern int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt);
extern void audit_signal_info(int sig, struct task_struct *t);
extern int audit_filter_user(int pid, int type);
extern int audit_filter_user(struct netlink_skb_parms *cb, int type);
#else
#define audit_alloc(t) ({ 0; })
#define audit_free(t) do { ; } while (0)
@ -253,7 +254,7 @@ extern int audit_filter_user(int pid, int type);
#define audit_sockaddr(len, addr) ({ 0; })
#define audit_avc_path(dentry, mnt) ({ 0; })
#define audit_signal_info(s,t) do { ; } while (0)
#define audit_filter_user(p,t) ({ 1; })
#define audit_filter_user(cb,t) ({ 1; })
#endif
#ifdef CONFIG_AUDIT

2
kernel/audit.c
View File

@ -434,7 +434,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
if (!audit_enabled && msg_type != AUDIT_USER_AVC)
return 0;
err = audit_filter_user(pid, msg_type);
err = audit_filter_user(&NETLINK_CB(skb), msg_type);
if (err == 1) {
err = 0;
ab = audit_log_start(NULL, GFP_KERNEL, msg_type);

56
kernel/auditsc.c
View File

@ -40,6 +40,7 @@
#include <linux/personality.h>
#include <linux/time.h>
#include <linux/kthread.h>
#include <linux/netlink.h>
#include <asm/unistd.h>
/* 0 = no checking
@ -530,35 +531,62 @@ static enum audit_state audit_filter_syscall(struct task_struct *tsk,
return AUDIT_BUILD_CONTEXT;
}
int audit_filter_user(int pid, int type)
static int audit_filter_user_rules(struct netlink_skb_parms *cb,
struct audit_rule *rule,
enum audit_state *state)
{
int i;
for (i = 0; i < rule->field_count; i++) {
u32 field = rule->fields[i] & ~AUDIT_NEGATE;
u32 value = rule->values[i];
int result = 0;
switch (field) {
case AUDIT_PID:
result = (cb->creds.pid == value);
break;
case AUDIT_UID:
result = (cb->creds.uid == value);
break;
case AUDIT_GID:
result = (cb->creds.gid == value);
break;
case AUDIT_LOGINUID:
result = (cb->loginuid == value);
break;
}
if (rule->fields[i] & AUDIT_NEGATE)
result = !result;
if (!result)
return 0;
}
switch (rule->action) {
case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
case AUDIT_POSSIBLE: *state = AUDIT_BUILD_CONTEXT; break;
case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
}
return 1;
}
int audit_filter_user(struct netlink_skb_parms *cb, int type)
{
struct task_struct *tsk;
struct audit_entry *e;
enum audit_state state;
int ret = 1;
read_lock(&tasklist_lock);
tsk = find_task_by_pid(pid);
if (tsk)
get_task_struct(tsk);
read_unlock(&tasklist_lock);
if (!tsk)
return -ESRCH;
rcu_read_lock();
list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
if (audit_filter_rules(tsk, &e->rule, NULL, &state)) {
if (audit_filter_user_rules(cb, &e->rule, &state)) {
if (state == AUDIT_DISABLED)
ret = 0;
break;
}
}
rcu_read_unlock();
put_task_struct(tsk);
return ret; /* Audit by default */
}
/* This should be called with task_lock() held. */