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authorLinus Torvalds <torvalds@g5.osdl.org>2005-09-13 09:47:30 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2005-09-13 09:47:30 -0700
commit5d54e69c68c05b162a56f9914cae72afd7e6f40a (patch)
treec5933858c4861bc3e358559f64ef459a1f56ab75 /kernel/auditsc.c
parent63f3d1df1ad276a30b75339dd682a6e1f9d0c181 (diff)
parentb6ddc518520887a62728b0414efbf802a9dfdd55 (diff)
Merge master.kernel.org:/pub/scm/linux/kernel/git/dwmw2/audit-2.6
Diffstat (limited to 'kernel/auditsc.c')
-rw-r--r--kernel/auditsc.c327
1 files changed, 229 insertions, 98 deletions
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index e75f84e1a1a..88696f639aa 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -39,6 +39,9 @@
#include <linux/audit.h>
#include <linux/personality.h>
#include <linux/time.h>
+#include <linux/kthread.h>
+#include <linux/netlink.h>
+#include <linux/compiler.h>
#include <asm/unistd.h>
/* 0 = no checking
@@ -95,6 +98,7 @@ struct audit_names {
uid_t uid;
gid_t gid;
dev_t rdev;
+ unsigned flags;
};
struct audit_aux_data {
@@ -167,9 +171,16 @@ struct audit_context {
/* There are three lists of rules -- one to search at task creation
* time, one to search at syscall entry time, and another to search at
* syscall exit time. */
-static LIST_HEAD(audit_tsklist);
-static LIST_HEAD(audit_entlist);
-static LIST_HEAD(audit_extlist);
+static struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
+ LIST_HEAD_INIT(audit_filter_list[0]),
+ LIST_HEAD_INIT(audit_filter_list[1]),
+ LIST_HEAD_INIT(audit_filter_list[2]),
+ LIST_HEAD_INIT(audit_filter_list[3]),
+ LIST_HEAD_INIT(audit_filter_list[4]),
+#if AUDIT_NR_FILTERS != 5
+#error Fix audit_filter_list initialiser
+#endif
+};
struct audit_entry {
struct list_head list;
@@ -179,9 +190,36 @@ struct audit_entry {
extern int audit_pid;
+/* Copy rule from user-space to kernel-space. Called from
+ * audit_add_rule during AUDIT_ADD. */
+static inline int audit_copy_rule(struct audit_rule *d, struct audit_rule *s)
+{
+ int i;
+
+ if (s->action != AUDIT_NEVER
+ && s->action != AUDIT_POSSIBLE
+ && s->action != AUDIT_ALWAYS)
+ return -1;
+ if (s->field_count < 0 || s->field_count > AUDIT_MAX_FIELDS)
+ return -1;
+ if ((s->flags & ~AUDIT_FILTER_PREPEND) >= AUDIT_NR_FILTERS)
+ return -1;
+
+ d->flags = s->flags;
+ d->action = s->action;
+ d->field_count = s->field_count;
+ for (i = 0; i < d->field_count; i++) {
+ d->fields[i] = s->fields[i];
+ d->values[i] = s->values[i];
+ }
+ for (i = 0; i < AUDIT_BITMASK_SIZE; i++) d->mask[i] = s->mask[i];
+ return 0;
+}
+
/* Check to see if two rules are identical. It is called from
+ * audit_add_rule during AUDIT_ADD and
* audit_del_rule during AUDIT_DEL. */
-static int audit_compare_rule(struct audit_rule *a, struct audit_rule *b)
+static inline int audit_compare_rule(struct audit_rule *a, struct audit_rule *b)
{
int i;
@@ -210,19 +248,37 @@ static int audit_compare_rule(struct audit_rule *a, struct audit_rule *b)
/* Note that audit_add_rule and audit_del_rule are called via
* audit_receive() in audit.c, and are protected by
* audit_netlink_sem. */
-static inline int audit_add_rule(struct audit_entry *entry,
- struct list_head *list)
+static inline int audit_add_rule(struct audit_rule *rule,
+ struct list_head *list)
{
- if (entry->rule.flags & AUDIT_PREPEND) {
- entry->rule.flags &= ~AUDIT_PREPEND;
+ struct audit_entry *entry;
+
+ /* Do not use the _rcu iterator here, since this is the only
+ * addition routine. */
+ list_for_each_entry(entry, list, list) {
+ if (!audit_compare_rule(rule, &entry->rule)) {
+ return -EEXIST;
+ }
+ }
+
+ if (!(entry = kmalloc(sizeof(*entry), GFP_KERNEL)))
+ return -ENOMEM;
+ if (audit_copy_rule(&entry->rule, rule)) {
+ kfree(entry);
+ return -EINVAL;
+ }
+
+ if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
+ entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
list_add_rcu(&entry->list, list);
} else {
list_add_tail_rcu(&entry->list, list);
}
+
return 0;
}
-static void audit_free_rule(struct rcu_head *head)
+static inline void audit_free_rule(struct rcu_head *head)
{
struct audit_entry *e = container_of(head, struct audit_entry, rcu);
kfree(e);
@@ -245,82 +301,82 @@ static inline int audit_del_rule(struct audit_rule *rule,
return 0;
}
}
- return -EFAULT; /* No matching rule */
+ return -ENOENT; /* No matching rule */
}
-/* Copy rule from user-space to kernel-space. Called during
- * AUDIT_ADD. */
-static int audit_copy_rule(struct audit_rule *d, struct audit_rule *s)
+static int audit_list_rules(void *_dest)
{
+ int pid, seq;
+ int *dest = _dest;
+ struct audit_entry *entry;
int i;
- if (s->action != AUDIT_NEVER
- && s->action != AUDIT_POSSIBLE
- && s->action != AUDIT_ALWAYS)
- return -1;
- if (s->field_count < 0 || s->field_count > AUDIT_MAX_FIELDS)
- return -1;
+ pid = dest[0];
+ seq = dest[1];
+ kfree(dest);
- d->flags = s->flags;
- d->action = s->action;
- d->field_count = s->field_count;
- for (i = 0; i < d->field_count; i++) {
- d->fields[i] = s->fields[i];
- d->values[i] = s->values[i];
+ down(&audit_netlink_sem);
+
+ /* The *_rcu iterators not needed here because we are
+ always called with audit_netlink_sem held. */
+ for (i=0; i<AUDIT_NR_FILTERS; i++) {
+ list_for_each_entry(entry, &audit_filter_list[i], list)
+ audit_send_reply(pid, seq, AUDIT_LIST, 0, 1,
+ &entry->rule, sizeof(entry->rule));
}
- for (i = 0; i < AUDIT_BITMASK_SIZE; i++) d->mask[i] = s->mask[i];
+ audit_send_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
+
+ up(&audit_netlink_sem);
return 0;
}
int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
uid_t loginuid)
{
- u32 flags;
- struct audit_entry *entry;
+ struct task_struct *tsk;
+ int *dest;
int err = 0;
+ unsigned listnr;
switch (type) {
case AUDIT_LIST:
- /* The *_rcu iterators not needed here because we are
- always called with audit_netlink_sem held. */
- list_for_each_entry(entry, &audit_tsklist, list)
- audit_send_reply(pid, seq, AUDIT_LIST, 0, 1,
- &entry->rule, sizeof(entry->rule));
- list_for_each_entry(entry, &audit_entlist, list)
- audit_send_reply(pid, seq, AUDIT_LIST, 0, 1,
- &entry->rule, sizeof(entry->rule));
- list_for_each_entry(entry, &audit_extlist, list)
- audit_send_reply(pid, seq, AUDIT_LIST, 0, 1,
- &entry->rule, sizeof(entry->rule));
- audit_send_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 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(2 * sizeof(int), GFP_KERNEL);
+ if (!dest)
+ return -ENOMEM;
+ dest[0] = pid;
+ dest[1] = seq;
+
+ tsk = kthread_run(audit_list_rules, dest, "audit_list_rules");
+ if (IS_ERR(tsk)) {
+ kfree(dest);
+ err = PTR_ERR(tsk);
+ }
break;
case AUDIT_ADD:
- if (!(entry = kmalloc(sizeof(*entry), GFP_KERNEL)))
- return -ENOMEM;
- if (audit_copy_rule(&entry->rule, data)) {
- kfree(entry);
+ listnr =((struct audit_rule *)data)->flags & ~AUDIT_FILTER_PREPEND;
+ if (listnr >= AUDIT_NR_FILTERS)
return -EINVAL;
- }
- flags = entry->rule.flags;
- if (!err && (flags & AUDIT_PER_TASK))
- err = audit_add_rule(entry, &audit_tsklist);
- if (!err && (flags & AUDIT_AT_ENTRY))
- err = audit_add_rule(entry, &audit_entlist);
- if (!err && (flags & AUDIT_AT_EXIT))
- err = audit_add_rule(entry, &audit_extlist);
- audit_log(NULL, AUDIT_CONFIG_CHANGE,
- "auid=%u added an audit rule\n", loginuid);
+
+ err = audit_add_rule(data, &audit_filter_list[listnr]);
+ if (!err)
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+ "auid=%u added an audit rule\n", loginuid);
break;
case AUDIT_DEL:
- flags =((struct audit_rule *)data)->flags;
- if (!err && (flags & AUDIT_PER_TASK))
- err = audit_del_rule(data, &audit_tsklist);
- if (!err && (flags & AUDIT_AT_ENTRY))
- err = audit_del_rule(data, &audit_entlist);
- if (!err && (flags & AUDIT_AT_EXIT))
- err = audit_del_rule(data, &audit_extlist);
- audit_log(NULL, AUDIT_CONFIG_CHANGE,
- "auid=%u removed an audit rule\n", loginuid);
+ listnr =((struct audit_rule *)data)->flags & ~AUDIT_FILTER_PREPEND;
+ if (listnr >= AUDIT_NR_FILTERS)
+ return -EINVAL;
+
+ err = audit_del_rule(data, &audit_filter_list[listnr]);
+ if (!err)
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+ "auid=%u removed an audit rule\n", loginuid);
break;
default:
return -EINVAL;
@@ -384,8 +440,12 @@ static int audit_filter_rules(struct task_struct *tsk,
result = (ctx->return_code == value);
break;
case AUDIT_SUCCESS:
- if (ctx && ctx->return_valid)
- result = (ctx->return_valid == AUDITSC_SUCCESS);
+ if (ctx && ctx->return_valid) {
+ if (value)
+ result = (ctx->return_valid == AUDITSC_SUCCESS);
+ else
+ result = (ctx->return_valid == AUDITSC_FAILURE);
+ }
break;
case AUDIT_DEVMAJOR:
if (ctx) {
@@ -454,7 +514,7 @@ static enum audit_state audit_filter_task(struct task_struct *tsk)
enum audit_state state;
rcu_read_lock();
- list_for_each_entry_rcu(e, &audit_tsklist, list) {
+ list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) {
if (audit_filter_rules(tsk, &e->rule, NULL, &state)) {
rcu_read_unlock();
return state;
@@ -474,20 +534,84 @@ static enum audit_state audit_filter_syscall(struct task_struct *tsk,
struct list_head *list)
{
struct audit_entry *e;
+ enum audit_state state;
+
+ if (audit_pid && tsk->tgid == audit_pid)
+ return AUDIT_DISABLED;
+
+ rcu_read_lock();
+ if (!list_empty(list)) {
+ int word = AUDIT_WORD(ctx->major);
+ int bit = AUDIT_BIT(ctx->major);
+
+ list_for_each_entry_rcu(e, list, list) {
+ if ((e->rule.mask[word] & bit) == bit
+ && audit_filter_rules(tsk, &e->rule, ctx, &state)) {
+ rcu_read_unlock();
+ return state;
+ }
+ }
+ }
+ rcu_read_unlock();
+ return AUDIT_BUILD_CONTEXT;
+}
+
+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 audit_entry *e;
enum audit_state state;
- int word = AUDIT_WORD(ctx->major);
- int bit = AUDIT_BIT(ctx->major);
+ int ret = 1;
rcu_read_lock();
- list_for_each_entry_rcu(e, list, list) {
- if ((e->rule.mask[word] & bit) == bit
- && audit_filter_rules(tsk, &e->rule, ctx, &state)) {
- rcu_read_unlock();
- return state;
+ list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
+ if (audit_filter_user_rules(cb, &e->rule, &state)) {
+ if (state == AUDIT_DISABLED)
+ ret = 0;
+ break;
}
}
rcu_read_unlock();
- return AUDIT_BUILD_CONTEXT;
+
+ return ret; /* Audit by default */
}
/* This should be called with task_lock() held. */
@@ -504,7 +628,7 @@ static inline struct audit_context *audit_get_context(struct task_struct *tsk,
if (context->in_syscall && !context->auditable) {
enum audit_state state;
- state = audit_filter_syscall(tsk, context, &audit_extlist);
+ state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);
if (state == AUDIT_RECORD_CONTEXT)
context->auditable = 1;
}
@@ -679,13 +803,13 @@ static void audit_log_task_info(struct audit_buffer *ab)
up_read(&mm->mmap_sem);
}
-static void audit_log_exit(struct audit_context *context)
+static void audit_log_exit(struct audit_context *context, unsigned int gfp_mask)
{
int i;
struct audit_buffer *ab;
struct audit_aux_data *aux;
- ab = audit_log_start(context, AUDIT_SYSCALL);
+ ab = audit_log_start(context, gfp_mask, AUDIT_SYSCALL);
if (!ab)
return; /* audit_panic has been called */
audit_log_format(ab, "arch=%x syscall=%d",
@@ -717,7 +841,7 @@ static void audit_log_exit(struct audit_context *context)
for (aux = context->aux; aux; aux = aux->next) {
- ab = audit_log_start(context, aux->type);
+ ab = audit_log_start(context, GFP_KERNEL, aux->type);
if (!ab)
continue; /* audit_panic has been called */
@@ -754,14 +878,14 @@ static void audit_log_exit(struct audit_context *context)
}
if (context->pwd && context->pwdmnt) {
- ab = audit_log_start(context, AUDIT_CWD);
+ ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
if (ab) {
audit_log_d_path(ab, "cwd=", context->pwd, context->pwdmnt);
audit_log_end(ab);
}
}
for (i = 0; i < context->name_count; i++) {
- ab = audit_log_start(context, AUDIT_PATH);
+ ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
if (!ab)
continue; /* audit_panic has been called */
@@ -770,6 +894,8 @@ static void audit_log_exit(struct audit_context *context)
audit_log_format(ab, " name=");
audit_log_untrustedstring(ab, context->names[i].name);
}
+ audit_log_format(ab, " flags=%x\n", context->names[i].flags);
+
if (context->names[i].ino != (unsigned long)-1)
audit_log_format(ab, " inode=%lu dev=%02x:%02x mode=%#o"
" ouid=%u ogid=%u rdev=%02x:%02x",
@@ -799,9 +925,11 @@ void audit_free(struct task_struct *tsk)
return;
/* Check for system calls that do not go through the exit
- * function (e.g., exit_group), then free context block. */
- if (context->in_syscall && context->auditable && context->pid != audit_pid)
- audit_log_exit(context);
+ * function (e.g., exit_group), then free context block.
+ * We use GFP_ATOMIC here because we might be doing this
+ * in the context of the idle thread */
+ if (context->in_syscall && context->auditable)
+ audit_log_exit(context, GFP_ATOMIC);
audit_free_context(context);
}
@@ -876,11 +1004,11 @@ void audit_syscall_entry(struct task_struct *tsk, int arch, int major,
state = context->state;
if (state == AUDIT_SETUP_CONTEXT || state == AUDIT_BUILD_CONTEXT)
- state = audit_filter_syscall(tsk, context, &audit_entlist);
+ state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]);
if (likely(state == AUDIT_DISABLED))
return;
- context->serial = audit_serial();
+ context->serial = 0;
context->ctime = CURRENT_TIME;
context->in_syscall = 1;
context->auditable = !!(state == AUDIT_RECORD_CONTEXT);
@@ -903,10 +1031,10 @@ void audit_syscall_exit(struct task_struct *tsk, int valid, long return_code)
/* Not having a context here is ok, since the parent may have
* called __put_task_struct. */
if (likely(!context))
- return;
+ goto out;
- if (context->in_syscall && context->auditable && context->pid != audit_pid)
- audit_log_exit(context);
+ if (context->in_syscall && context->auditable)
+ audit_log_exit(context, GFP_KERNEL);
context->in_syscall = 0;
context->auditable = 0;
@@ -919,9 +1047,9 @@ void audit_syscall_exit(struct task_struct *tsk, int valid, long return_code)
} else {
audit_free_names(context);
audit_free_aux(context);
- audit_zero_context(context, context->state);
tsk->audit_context = context;
}
+ out:
put_task_struct(tsk);
}
@@ -996,7 +1124,7 @@ void audit_putname(const char *name)
/* Store the inode and device from a lookup. Called from
* fs/namei.c:path_lookup(). */
-void audit_inode(const char *name, const struct inode *inode)
+void audit_inode(const char *name, const struct inode *inode, unsigned flags)
{
int idx;
struct audit_context *context = current->audit_context;
@@ -1022,17 +1150,20 @@ void audit_inode(const char *name, const struct inode *inode)
++context->ino_count;
#endif
}
- context->names[idx].ino = inode->i_ino;
- context->names[idx].dev = inode->i_sb->s_dev;
- context->names[idx].mode = inode->i_mode;
- context->names[idx].uid = inode->i_uid;
- context->names[idx].gid = inode->i_gid;
- context->names[idx].rdev = inode->i_rdev;
+ context->names[idx].flags = flags;
+ context->names[idx].ino = inode->i_ino;
+ context->names[idx].dev = inode->i_sb->s_dev;
+ context->names[idx].mode = inode->i_mode;
+ context->names[idx].uid = inode->i_uid;
+ context->names[idx].gid = inode->i_gid;
+ context->names[idx].rdev = inode->i_rdev;
}
void auditsc_get_stamp(struct audit_context *ctx,
struct timespec *t, unsigned int *serial)
{
+ if (!ctx->serial)
+ ctx->serial = audit_serial();
t->tv_sec = ctx->ctime.tv_sec;
t->tv_nsec = ctx->ctime.tv_nsec;
*serial = ctx->serial;
@@ -1044,7 +1175,7 @@ int audit_set_loginuid(struct task_struct *task, uid_t loginuid)
if (task->audit_context) {
struct audit_buffer *ab;
- ab = audit_log_start(NULL, AUDIT_LOGIN);
+ ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
if (ab) {
audit_log_format(ab, "login pid=%d uid=%u "
"old auid=%u new auid=%u",
@@ -1153,7 +1284,7 @@ void audit_signal_info(int sig, struct task_struct *t)
extern pid_t audit_sig_pid;
extern uid_t audit_sig_uid;
- if (unlikely(audit_pid && t->pid == audit_pid)) {
+ if (unlikely(audit_pid && t->tgid == audit_pid)) {
if (sig == SIGTERM || sig == SIGHUP) {
struct audit_context *ctx = current->audit_context;
audit_sig_pid = current->pid;