fixing audit rule ordering mess, part 1
Problem: ordering between the rules on exit chain is currently lost;
all watch and inode rules are listed after everything else _and_
exit,never on one kind doesn't stop exit,always on another from
being matched.
Solution: assign priorities to rules, keep track of the current
highest-priority matching rule and its result (always/never).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index c76a582..19d2c27 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -165,14 +165,14 @@
struct audit_context {
int dummy; /* must be the first element */
int in_syscall; /* 1 if task is in a syscall */
- enum audit_state state;
+ enum audit_state state, current_state;
unsigned int serial; /* serial number for record */
struct timespec ctime; /* time of syscall entry */
int major; /* syscall number */
unsigned long argv[4]; /* syscall arguments */
int return_valid; /* return code is valid */
long return_code;/* syscall return code */
- int auditable; /* 1 if record should be written */
+ u64 prio;
int name_count;
struct audit_names names[AUDIT_NAMES];
char * filterkey; /* key for rule that triggered record */
@@ -630,8 +630,16 @@
return 0;
}
}
- if (rule->filterkey && ctx)
- ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);
+
+ if (ctx) {
+ if (rule->prio <= ctx->prio)
+ return 0;
+ if (rule->filterkey) {
+ kfree(ctx->filterkey);
+ ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);
+ }
+ ctx->prio = rule->prio;
+ }
switch (rule->action) {
case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
@@ -685,6 +693,7 @@
audit_filter_rules(tsk, &e->rule, ctx, NULL,
&state)) {
rcu_read_unlock();
+ ctx->current_state = state;
return state;
}
}
@@ -698,15 +707,14 @@
* buckets applicable to the inode numbers in audit_names[].
* Regarding audit_state, same rules apply as for audit_filter_syscall().
*/
-enum audit_state audit_filter_inodes(struct task_struct *tsk,
- struct audit_context *ctx)
+void audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx)
{
int i;
struct audit_entry *e;
enum audit_state state;
if (audit_pid && tsk->tgid == audit_pid)
- return AUDIT_DISABLED;
+ return;
rcu_read_lock();
for (i = 0; i < ctx->name_count; i++) {
@@ -723,17 +731,20 @@
if ((e->rule.mask[word] & bit) == bit &&
audit_filter_rules(tsk, &e->rule, ctx, n, &state)) {
rcu_read_unlock();
- return state;
+ ctx->current_state = state;
+ return;
}
}
}
rcu_read_unlock();
- return AUDIT_BUILD_CONTEXT;
}
-void audit_set_auditable(struct audit_context *ctx)
+static void audit_set_auditable(struct audit_context *ctx)
{
- ctx->auditable = 1;
+ if (!ctx->prio) {
+ ctx->prio = 1;
+ ctx->current_state = AUDIT_RECORD_CONTEXT;
+ }
}
static inline struct audit_context *audit_get_context(struct task_struct *tsk,
@@ -764,23 +775,11 @@
else
context->return_code = return_code;
- if (context->in_syscall && !context->dummy && !context->auditable) {
- enum audit_state state;
-
- state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);
- if (state == AUDIT_RECORD_CONTEXT) {
- context->auditable = 1;
- goto get_context;
- }
-
- state = audit_filter_inodes(tsk, context);
- if (state == AUDIT_RECORD_CONTEXT)
- context->auditable = 1;
-
+ if (context->in_syscall && !context->dummy) {
+ audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);
+ audit_filter_inodes(tsk, context);
}
-get_context:
-
tsk->audit_context = NULL;
return context;
}
@@ -790,8 +789,7 @@
int i;
#if AUDIT_DEBUG == 2
- if (context->auditable
- ||context->put_count + context->ino_count != context->name_count) {
+ if (context->put_count + context->ino_count != context->name_count) {
printk(KERN_ERR "%s:%d(:%d): major=%d in_syscall=%d"
" name_count=%d put_count=%d"
" ino_count=%d [NOT freeing]\n",
@@ -842,6 +840,7 @@
{
memset(context, 0, sizeof(*context));
context->state = state;
+ context->prio = state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
}
static inline struct audit_context *audit_alloc_context(enum audit_state state)
@@ -1543,7 +1542,7 @@
* We use GFP_ATOMIC here because we might be doing this
* in the context of the idle thread */
/* that can happen only if we are called from do_exit() */
- if (context->in_syscall && context->auditable)
+ if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
audit_log_exit(context, tsk);
audit_free_context(context);
@@ -1627,15 +1626,17 @@
state = context->state;
context->dummy = !audit_n_rules;
- if (!context->dummy && (state == AUDIT_SETUP_CONTEXT || state == AUDIT_BUILD_CONTEXT))
+ if (!context->dummy && state == AUDIT_BUILD_CONTEXT) {
+ context->prio = 0;
state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]);
+ }
if (likely(state == AUDIT_DISABLED))
return;
context->serial = 0;
context->ctime = CURRENT_TIME;
context->in_syscall = 1;
- context->auditable = !!(state == AUDIT_RECORD_CONTEXT);
+ context->current_state = state;
context->ppid = 0;
}
@@ -1643,17 +1644,20 @@
{
struct audit_context *ctx = current->audit_context;
struct audit_context *p = child->audit_context;
- if (!p || !ctx || !ctx->auditable)
+ if (!p || !ctx)
+ return;
+ if (!ctx->in_syscall || ctx->current_state != AUDIT_RECORD_CONTEXT)
return;
p->arch = ctx->arch;
p->major = ctx->major;
memcpy(p->argv, ctx->argv, sizeof(ctx->argv));
p->ctime = ctx->ctime;
p->dummy = ctx->dummy;
- p->auditable = ctx->auditable;
p->in_syscall = ctx->in_syscall;
p->filterkey = kstrdup(ctx->filterkey, GFP_KERNEL);
p->ppid = current->pid;
+ p->prio = ctx->prio;
+ p->current_state = ctx->current_state;
}
/**
@@ -1677,11 +1681,11 @@
if (likely(!context))
return;
- if (context->in_syscall && context->auditable)
+ if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
audit_log_exit(context, tsk);
context->in_syscall = 0;
- context->auditable = 0;
+ context->prio = context->state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
if (context->previous) {
struct audit_context *new_context = context->previous;
@@ -2091,7 +2095,10 @@
t->tv_sec = ctx->ctime.tv_sec;
t->tv_nsec = ctx->ctime.tv_nsec;
*serial = ctx->serial;
- ctx->auditable = 1;
+ if (!ctx->prio) {
+ ctx->prio = 1;
+ ctx->current_state = AUDIT_RECORD_CONTEXT;
+ }
return 1;
}
