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-rw-r--r--kernel/audit.c41
-rw-r--r--kernel/audit.h38
-rw-r--r--kernel/auditfilter.c785
-rw-r--r--kernel/auditsc.c124
4 files changed, 900 insertions, 88 deletions
diff --git a/kernel/audit.c b/kernel/audit.c
index 0738a4b..0fbf1c1 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -56,6 +56,7 @@
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/selinux.h>
+#include <linux/inotify.h>
#include "audit.h"
@@ -103,6 +104,12 @@ static atomic_t audit_lost = ATOMIC_INIT(0);
/* The netlink socket. */
static struct sock *audit_sock;
+/* Inotify handle. */
+struct inotify_handle *audit_ih;
+
+/* Hash for inode-based rules */
+struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
+
/* The audit_freelist is a list of pre-allocated audit buffers (if more
* than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
* being placed on the freelist). */
@@ -115,10 +122,8 @@ static struct task_struct *kauditd_task;
static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
-/* The netlink socket is only to be read by 1 CPU, which lets us assume
- * that list additions and deletions never happen simultaneously in
- * auditsc.c */
-DEFINE_MUTEX(audit_netlink_mutex);
+/* Serialize requests from userspace. */
+static DEFINE_MUTEX(audit_cmd_mutex);
/* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
* audit records. Since printk uses a 1024 byte buffer, this buffer
@@ -373,8 +378,8 @@ int audit_send_list(void *_dest)
struct sk_buff *skb;
/* wait for parent to finish and send an ACK */
- mutex_lock(&audit_netlink_mutex);
- mutex_unlock(&audit_netlink_mutex);
+ mutex_lock(&audit_cmd_mutex);
+ mutex_unlock(&audit_cmd_mutex);
while ((skb = __skb_dequeue(&dest->q)) != NULL)
netlink_unicast(audit_sock, skb, pid, 0);
@@ -665,20 +670,30 @@ static void audit_receive(struct sock *sk, int length)
struct sk_buff *skb;
unsigned int qlen;
- mutex_lock(&audit_netlink_mutex);
+ mutex_lock(&audit_cmd_mutex);
for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
skb = skb_dequeue(&sk->sk_receive_queue);
audit_receive_skb(skb);
kfree_skb(skb);
}
- mutex_unlock(&audit_netlink_mutex);
+ mutex_unlock(&audit_cmd_mutex);
}
+#ifdef CONFIG_AUDITSYSCALL
+static const struct inotify_operations audit_inotify_ops = {
+ .handle_event = audit_handle_ievent,
+ .destroy_watch = audit_free_parent,
+};
+#endif
/* Initialize audit support at boot time. */
static int __init audit_init(void)
{
+#ifdef CONFIG_AUDITSYSCALL
+ int i;
+#endif
+
printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
audit_default ? "enabled" : "disabled");
audit_sock = netlink_kernel_create(NETLINK_AUDIT, 0, audit_receive,
@@ -697,6 +712,16 @@ static int __init audit_init(void)
selinux_audit_set_callback(&selinux_audit_rule_update);
audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
+
+#ifdef CONFIG_AUDITSYSCALL
+ audit_ih = inotify_init(&audit_inotify_ops);
+ if (IS_ERR(audit_ih))
+ audit_panic("cannot initialize inotify handle");
+
+ for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
+ INIT_LIST_HEAD(&audit_inode_hash[i]);
+#endif
+
return 0;
}
__initcall(audit_init);
diff --git a/kernel/audit.h b/kernel/audit.h
index 52cb1e3..58fa44cb 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -19,7 +19,6 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
-#include <linux/mutex.h>
#include <linux/fs.h>
#include <linux/audit.h>
#include <linux/skbuff.h>
@@ -54,6 +53,18 @@ enum audit_state {
};
/* Rule lists */
+struct audit_parent;
+
+struct audit_watch {
+ atomic_t count; /* reference count */
+ char *path; /* insertion path */
+ dev_t dev; /* associated superblock device */
+ unsigned long ino; /* associated inode number */
+ struct audit_parent *parent; /* associated parent */
+ struct list_head wlist; /* entry in parent->watches list */
+ struct list_head rules; /* associated rules */
+};
+
struct audit_field {
u32 type;
u32 val;
@@ -71,6 +82,9 @@ struct audit_krule {
u32 buflen; /* for data alloc on list rules */
u32 field_count;
struct audit_field *fields;
+ struct audit_field *inode_f; /* quick access to an inode field */
+ struct audit_watch *watch; /* associated watch */
+ struct list_head rlist; /* entry in audit_watch.rules list */
};
struct audit_entry {
@@ -79,10 +93,18 @@ struct audit_entry {
struct audit_krule rule;
};
-
extern int audit_pid;
-extern int audit_comparator(const u32 left, const u32 op, const u32 right);
+#define AUDIT_INODE_BUCKETS 32
+extern struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
+
+static inline int audit_hash_ino(u32 ino)
+{
+ return (ino & (AUDIT_INODE_BUCKETS-1));
+}
+
+extern int audit_comparator(const u32 left, const u32 op, const u32 right);
+extern int audit_compare_dname_path(const char *dname, const char *path);
extern struct sk_buff * audit_make_reply(int pid, int seq, int type,
int done, int multi,
void *payload, int size);
@@ -91,7 +113,6 @@ extern void audit_send_reply(int pid, int seq, int type,
void *payload, int size);
extern void audit_log_lost(const char *message);
extern void audit_panic(const char *message);
-extern struct mutex audit_netlink_mutex;
struct audit_netlink_list {
int pid;
@@ -100,6 +121,10 @@ struct audit_netlink_list {
int audit_send_list(void *);
+struct inotify_watch;
+extern void audit_free_parent(struct inotify_watch *);
+extern void audit_handle_ievent(struct inotify_watch *, u32, u32, u32,
+ const char *, struct inode *);
extern int selinux_audit_rule_update(void);
#ifdef CONFIG_AUDITSYSCALL
@@ -109,6 +134,11 @@ static inline void audit_signal_info(int sig, struct task_struct *t)
if (unlikely(audit_pid && t->tgid == audit_pid))
__audit_signal_info(sig, t);
}
+extern enum audit_state audit_filter_inodes(struct task_struct *,
+ struct audit_context *);
+extern void audit_set_auditable(struct audit_context *);
#else
#define audit_signal_info(s,t)
+#define audit_filter_inodes(t,c) AUDIT_DISABLED
+#define audit_set_auditable(c)
#endif
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index df9503d..03a6919 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -22,13 +22,59 @@
#include <linux/kernel.h>
#include <linux/audit.h>
#include <linux/kthread.h>
+#include <linux/mutex.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
#include <linux/netlink.h>
+#include <linux/sched.h>
+#include <linux/inotify.h>
#include <linux/selinux.h>
#include "audit.h"
-/* 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. */
+/*
+ * Locking model:
+ *
+ * audit_filter_mutex:
+ * Synchronizes writes and blocking reads of audit's filterlist
+ * data. Rcu is used to traverse the filterlist and access
+ * contents of structs audit_entry, audit_watch and opaque
+ * selinux rules during filtering. If modified, these structures
+ * must be copied and replace their counterparts in the filterlist.
+ * An audit_parent struct is not accessed during filtering, so may
+ * be written directly provided audit_filter_mutex is held.
+ */
+
+/*
+ * Reference counting:
+ *
+ * audit_parent: lifetime is from audit_init_parent() to receipt of an IN_IGNORED
+ * event. Each audit_watch holds a reference to its associated parent.
+ *
+ * audit_watch: if added to lists, lifetime is from audit_init_watch() to
+ * audit_remove_watch(). Additionally, an audit_watch may exist
+ * temporarily to assist in searching existing filter data. Each
+ * audit_krule holds a reference to its associated watch.
+ */
+
+struct audit_parent {
+ struct list_head ilist; /* entry in inotify registration list */
+ struct list_head watches; /* associated watches */
+ struct inotify_watch wdata; /* inotify watch data */
+ unsigned flags; /* status flags */
+};
+
+/*
+ * audit_parent status flags:
+ *
+ * AUDIT_PARENT_INVALID - set anytime rules/watches are auto-removed due to
+ * a filesystem event to ensure we're adding audit watches to a valid parent.
+ * Technically not needed for IN_DELETE_SELF or IN_UNMOUNT events, as we cannot
+ * receive them while we have nameidata, but must be used for IN_MOVE_SELF which
+ * we can receive while holding nameidata.
+ */
+#define AUDIT_PARENT_INVALID 0x001
+
+/* Audit filter lists, defined in <linux/audit.h> */
struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
LIST_HEAD_INIT(audit_filter_list[0]),
LIST_HEAD_INIT(audit_filter_list[1]),
@@ -41,9 +87,53 @@ struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
#endif
};
+static DEFINE_MUTEX(audit_filter_mutex);
+
+/* Inotify handle */
+extern struct inotify_handle *audit_ih;
+
+/* Inotify events we care about. */
+#define AUDIT_IN_WATCH IN_MOVE|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF
+
+void audit_free_parent(struct inotify_watch *i_watch)
+{
+ struct audit_parent *parent;
+
+ parent = container_of(i_watch, struct audit_parent, wdata);
+ WARN_ON(!list_empty(&parent->watches));
+ kfree(parent);
+}
+
+static inline void audit_get_watch(struct audit_watch *watch)
+{
+ atomic_inc(&watch->count);
+}
+
+static void audit_put_watch(struct audit_watch *watch)
+{
+ if (atomic_dec_and_test(&watch->count)) {
+ WARN_ON(watch->parent);
+ WARN_ON(!list_empty(&watch->rules));
+ kfree(watch->path);
+ kfree(watch);
+ }
+}
+
+static void audit_remove_watch(struct audit_watch *watch)
+{
+ list_del(&watch->wlist);
+ put_inotify_watch(&watch->parent->wdata);
+ watch->parent = NULL;
+ audit_put_watch(watch); /* match initial get */
+}
+
static inline void audit_free_rule(struct audit_entry *e)
{
int i;
+
+ /* some rules don't have associated watches */
+ if (e->rule.watch)
+ audit_put_watch(e->rule.watch);
if (e->rule.fields)
for (i = 0; i < e->rule.field_count; i++) {
struct audit_field *f = &e->rule.fields[i];
@@ -60,6 +150,50 @@ static inline void audit_free_rule_rcu(struct rcu_head *head)
audit_free_rule(e);
}
+/* Initialize a parent watch entry. */
+static struct audit_parent *audit_init_parent(struct nameidata *ndp)
+{
+ struct audit_parent *parent;
+ s32 wd;
+
+ parent = kzalloc(sizeof(*parent), GFP_KERNEL);
+ if (unlikely(!parent))
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&parent->watches);
+ parent->flags = 0;
+
+ inotify_init_watch(&parent->wdata);
+ /* grab a ref so inotify watch hangs around until we take audit_filter_mutex */
+ get_inotify_watch(&parent->wdata);
+ wd = inotify_add_watch(audit_ih, &parent->wdata, ndp->dentry->d_inode,
+ AUDIT_IN_WATCH);
+ if (wd < 0) {
+ audit_free_parent(&parent->wdata);
+ return ERR_PTR(wd);
+ }
+
+ return parent;
+}
+
+/* Initialize a watch entry. */
+static struct audit_watch *audit_init_watch(char *path)
+{
+ struct audit_watch *watch;
+
+ watch = kzalloc(sizeof(*watch), GFP_KERNEL);
+ if (unlikely(!watch))
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&watch->rules);
+ atomic_set(&watch->count, 1);
+ watch->path = path;
+ watch->dev = (dev_t)-1;
+ watch->ino = (unsigned long)-1;
+
+ return watch;
+}
+
/* Initialize an audit filterlist entry. */
static inline struct audit_entry *audit_init_entry(u32 field_count)
{
@@ -107,6 +241,43 @@ static char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
return str;
}
+/* Translate an inode field to kernel respresentation. */
+static inline int audit_to_inode(struct audit_krule *krule,
+ struct audit_field *f)
+{
+ if (krule->listnr != AUDIT_FILTER_EXIT ||
+ krule->watch || krule->inode_f)
+ return -EINVAL;
+
+ krule->inode_f = f;
+ return 0;
+}
+
+/* Translate a watch string to kernel respresentation. */
+static int audit_to_watch(struct audit_krule *krule, char *path, int len,
+ u32 op)
+{
+ struct audit_watch *watch;
+
+ if (!audit_ih)
+ return -EOPNOTSUPP;
+
+ if (path[0] != '/' || path[len-1] == '/' ||
+ krule->listnr != AUDIT_FILTER_EXIT ||
+ op & ~AUDIT_EQUAL ||
+ krule->inode_f || krule->watch) /* 1 inode # per rule, for hash */
+ return -EINVAL;
+
+ watch = audit_init_watch(path);
+ if (unlikely(IS_ERR(watch)))
+ return PTR_ERR(watch);
+
+ audit_get_watch(watch);
+ krule->watch = watch;
+
+ return 0;
+}
+
/* Common user-space to kernel rule translation. */
static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
{
@@ -161,6 +332,7 @@ exit_err:
static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
{
struct audit_entry *entry;
+ struct audit_field *f;
int err = 0;
int i;
@@ -175,14 +347,23 @@ static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
f->val = rule->values[i];
- if (f->type & AUDIT_UNUSED_BITS ||
- f->type == AUDIT_SE_USER ||
- f->type == AUDIT_SE_ROLE ||
- f->type == AUDIT_SE_TYPE ||
- f->type == AUDIT_SE_SEN ||
- f->type == AUDIT_SE_CLR) {
- err = -EINVAL;
+ err = -EINVAL;
+ if (f->type & AUDIT_UNUSED_BITS)
+ goto exit_free;
+
+ switch(f->type) {
+ case AUDIT_SE_USER:
+ case AUDIT_SE_ROLE:
+ case AUDIT_SE_TYPE:
+ case AUDIT_SE_SEN:
+ case AUDIT_SE_CLR:
+ case AUDIT_WATCH:
goto exit_free;
+ case AUDIT_INODE:
+ err = audit_to_inode(&entry->rule, f);
+ if (err)
+ goto exit_free;
+ break;
}
entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1;
@@ -199,6 +380,18 @@ static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
}
}
+ f = entry->rule.inode_f;
+ if (f) {
+ switch(f->op) {
+ case AUDIT_NOT_EQUAL:
+ entry->rule.inode_f = NULL;
+ case AUDIT_EQUAL:
+ break;
+ default:
+ goto exit_free;
+ }
+ }
+
exit_nofree:
return entry;
@@ -213,6 +406,7 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
{
int err = 0;
struct audit_entry *entry;
+ struct audit_field *f;
void *bufp;
size_t remain = datasz - sizeof(struct audit_rule_data);
int i;
@@ -263,6 +457,35 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
} else
f->se_str = str;
break;
+ case AUDIT_WATCH:
+ str = audit_unpack_string(&bufp, &remain, f->val);
+ if (IS_ERR(str))
+ goto exit_free;
+ entry->rule.buflen += f->val;
+
+ err = audit_to_watch(&entry->rule, str, f->val, f->op);
+ if (err) {
+ kfree(str);
+ goto exit_free;
+ }
+ break;
+ case AUDIT_INODE:
+ err = audit_to_inode(&entry->rule, f);
+ if (err)
+ goto exit_free;
+ break;
+ }
+ }
+
+ f = entry->rule.inode_f;
+ if (f) {
+ switch(f->op) {
+ case AUDIT_NOT_EQUAL:
+ entry->rule.inode_f = NULL;
+ case AUDIT_EQUAL:
+ break;
+ default:
+ goto exit_free;
}
}
@@ -346,6 +569,10 @@ static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
data->buflen += data->values[i] =
audit_pack_string(&bufp, f->se_str);
break;
+ case AUDIT_WATCH:
+ data->buflen += data->values[i] =
+ audit_pack_string(&bufp, krule->watch->path);
+ break;
default:
data->values[i] = f->val;
}
@@ -381,6 +608,10 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
if (strcmp(a->fields[i].se_str, b->fields[i].se_str))
return 1;
break;
+ case AUDIT_WATCH:
+ if (strcmp(a->watch->path, b->watch->path))
+ return 1;
+ break;
default:
if (a->fields[i].val != b->fields[i].val)
return 1;
@@ -394,6 +625,32 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
return 0;
}
+/* Duplicate the given audit watch. The new watch's rules list is initialized
+ * to an empty list and wlist is undefined. */
+static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
+{
+ char *path;
+ struct audit_watch *new;
+
+ path = kstrdup(old->path, GFP_KERNEL);
+ if (unlikely(!path))
+ return ERR_PTR(-ENOMEM);
+
+ new = audit_init_watch(path);
+ if (unlikely(IS_ERR(new))) {
+ kfree(path);
+ goto out;
+ }
+
+ new->dev = old->dev;
+ new->ino = old->ino;
+ get_inotify_watch(&old->parent->wdata);
+ new->parent = old->parent;
+
+out:
+ return new;
+}
+
/* Duplicate selinux field information. The se_rule is opaque, so must be
* re-initialized. */
static inline int audit_dupe_selinux_field(struct audit_field *df,
@@ -425,8 +682,11 @@ static inline int audit_dupe_selinux_field(struct audit_field *df,
/* Duplicate an audit rule. This will be a deep copy with the exception
* of the watch - that pointer is carried over. The selinux specific fields
* will be updated in the copy. The point is to be able to replace the old
- * rule with the new rule in the filterlist, then free the old rule. */
-static struct audit_entry *audit_dupe_rule(struct audit_krule *old)
+ * rule with the new rule in the filterlist, then free the old rule.
+ * The rlist element is undefined; list manipulations are handled apart from
+ * the initial copy. */
+static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
+ struct audit_watch *watch)
{
u32 fcount = old->field_count;
struct audit_entry *entry;
@@ -445,6 +705,8 @@ static struct audit_entry *audit_dupe_rule(struct audit_krule *old)
for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
new->mask[i] = old->mask[i];
new->buflen = old->buflen;
+ new->inode_f = old->inode_f;
+ new->watch = NULL;
new->field_count = old->field_count;
memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
@@ -466,21 +728,318 @@ static struct audit_entry *audit_dupe_rule(struct audit_krule *old)
}
}
+ if (watch) {
+ audit_get_watch(watch);
+ new->watch = watch;
+ }
+
return entry;
}
-/* Add rule to given filterlist if not a duplicate. Protected by
- * audit_netlink_mutex. */
+/* Update inode info in audit rules based on filesystem event. */
+static void audit_update_watch(struct audit_parent *parent,
+ const char *dname, dev_t dev,
+ unsigned long ino, unsigned invalidating)
+{
+ struct audit_watch *owatch, *nwatch, *nextw;
+ struct audit_krule *r, *nextr;
+ struct audit_entry *oentry, *nentry;
+ struct audit_buffer *ab;
+
+ mutex_lock(&audit_filter_mutex);
+ list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
+ if (audit_compare_dname_path(dname, owatch->path))
+ continue;
+
+ /* If the update involves invalidating rules, do the inode-based
+ * filtering now, so we don't omit records. */
+ if (invalidating &&
+ audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT)
+ audit_set_auditable(current->audit_context);
+
+ nwatch = audit_dupe_watch(owatch);
+ if (unlikely(IS_ERR(nwatch))) {
+ mutex_unlock(&audit_filter_mutex);
+ audit_panic("error updating watch, skipping");
+ return;
+ }
+ nwatch->dev = dev;
+ nwatch->ino = ino;
+
+ list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
+
+ oentry = container_of(r, struct audit_entry, rule);
+ list_del(&oentry->rule.rlist);
+ list_del_rcu(&oentry->list);
+
+ nentry = audit_dupe_rule(&oentry->rule, nwatch);
+ if (unlikely(IS_ERR(nentry)))
+ audit_panic("error updating watch, removing");
+ else {
+ int h = audit_hash_ino((u32)ino);
+ list_add(&nentry->rule.rlist, &nwatch->rules);
+ list_add_rcu(&nentry->list, &audit_inode_hash[h]);
+ }
+
+ call_rcu(&oentry->rcu, audit_free_rule_rcu);
+ }
+
+ ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
+ audit_log_format(ab, "audit updated rules specifying watch=");
+ audit_log_untrustedstring(ab, owatch->path);
+ audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino);
+ audit_log_end(ab);
+
+ audit_remove_watch(owatch);
+ goto add_watch_to_parent; /* event applies to a single watch */
+ }
+ mutex_unlock(&audit_filter_mutex);
+ return;
+
+add_watch_to_parent:
+ list_add(&nwatch->wlist, &parent->watches);
+ mutex_unlock(&audit_filter_mutex);
+ return;
+}
+
+/* Remove all watches & rules associated with a parent that is going away. */
+static void audit_remove_parent_watches(struct audit_parent *parent)
+{
+ struct audit_watch *w, *nextw;
+ struct audit_krule *r, *nextr;
+ struct audit_entry *e;
+
+ mutex_lock(&audit_filter_mutex);
+ parent->flags |= AUDIT_PARENT_INVALID;
+ list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
+ list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
+ e = container_of(r, struct audit_entry, rule);
+ list_del(&r->rlist);
+ list_del_rcu(&e->list);
+ call_rcu(&e->rcu, audit_free_rule_rcu);
+
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+ "audit implicitly removed rule from list=%d\n",
+ AUDIT_FILTER_EXIT);
+ }
+ audit_remove_watch(w);
+ }
+ mutex_unlock(&audit_filter_mutex);
+}
+
+/* Unregister inotify watches for parents on in_list.
+ * Generates an IN_IGNORED event. */
+static void audit_inotify_unregister(struct list_head *in_list)
+{
+ struct audit_parent *p, *n;
+
+ list_for_each_entry_safe(p, n, in_list, ilist) {
+ list_del(&p->ilist);
+ inotify_rm_watch(audit_ih, &p->wdata);
+ /* the put matching the get in audit_do_del_rule() */
+ put_inotify_watch(&p->wdata);
+ }
+}
+
+/* Find an existing audit rule.
+ * Caller must hold audit_filter_mutex to prevent stale rule data. */
+static struct audit_entry *audit_find_rule(struct audit_entry *entry,
+ struct list_head *list)
+{
+ struct audit_entry *e, *found = NULL;
+ int h;
+
+ if (entry->rule.watch) {
+ /* we don't know the inode number, so must walk entire hash */
+ for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
+ list = &audit_inode_hash[h];
+ list_for_each_entry(e, list, list)
+ if (!audit_compare_rule(&entry->rule, &e->rule)) {
+ found = e;
+ goto out;
+ }
+ }
+ goto out;
+ }
+
+ list_for_each_entry(e, list, list)
+ if (!audit_compare_rule(&entry->rule, &e->rule)) {
+ found = e;
+ goto out;
+ }
+
+out:
+ return found;
+}
+
+/* Get path information necessary for adding watches. */
+static int audit_get_nd(char *path, struct nameidata **ndp,
+ struct nameidata **ndw)
+{
+ struct nameidata *ndparent, *ndwatch;
+ int err;
+
+ ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
+ if (unlikely(!ndparent))
+ return -ENOMEM;
+
+ ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
+ if (unlikely(!ndwatch)) {
+ kfree(ndparent);
+ return -ENOMEM;
+ }
+
+ err = path_lookup(path, LOOKUP_PARENT, ndparent);
+ if (err) {
+ kfree(ndparent);
+ kfree(ndwatch);
+ return err;
+ }
+
+ err = path_lookup(path, 0, ndwatch);
+ if (err) {
+ kfree(ndwatch);
+ ndwatch = NULL;
+ }
+
+ *ndp = ndparent;
+ *ndw = ndwatch;
+
+ return 0;
+}
+
+/* Release resources used for watch path information. */
+static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
+{
+ if (ndp) {
+ path_release(ndp);
+ kfree(ndp);
+ }
+ if (ndw) {
+ path_release(ndw);
+ kfree(ndw);
+ }
+}
+
+/* Associate the given rule with an existing parent inotify_watch.
+ * Caller must hold audit_filter_mutex. */
+static void audit_add_to_parent(struct audit_krule *krule,
+ struct audit_parent *parent)
+{
+ struct audit_watch *w, *watch = krule->watch;
+ int watch_found = 0;
+
+ list_for_each_entry(w, &parent->watches, wlist) {
+ if (strcmp(watch->path, w->path))
+ continue;
+
+ watch_found = 1;
+
+ /* put krule's and initial refs to temporary watch */
+ audit_put_watch(watch);
+ audit_put_watch(watch);
+
+ audit_get_watch(w);
+ krule->watch = watch = w;
+ break;
+ }
+
+ if (!watch_found) {
+ get_inotify_watch(&parent->wdata);
+ watch->parent = parent;
+
+ list_add(&watch->wlist, &parent->watches);
+ }
+ list_add(&krule->rlist, &watch->rules);
+}
+
+/* Find a matching watch entry, or add this one.
+ * Caller must hold audit_filter_mutex. */
+static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
+ struct nameidata *ndw)
+{
+ struct audit_watch *watch = krule->watch;
+ struct inotify_watch *i_watch;
+ struct audit_parent *parent;
+ int ret = 0;
+
+ /* update watch filter fields */
+ if (ndw) {
+ watch->dev = ndw->dentry->d_inode->i_sb->s_dev;
+ watch->ino = ndw->dentry->d_inode->i_ino;
+ }
+
+ /* The audit_filter_mutex must not be held during inotify calls because
+ * we hold it during inotify event callback processing. If an existing
+ * inotify watch is found, inotify_find_watch() grabs a reference before
+ * returning.
+ */
+ mutex_unlock(&audit_filter_mutex);
+
+ if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) {
+ parent = audit_init_parent(ndp);
+ if (IS_ERR(parent)) {
+ /* caller expects mutex locked */
+ mutex_lock(&audit_filter_mutex);
+ return PTR_ERR(parent);
+ }
+ } else
+ parent = container_of(i_watch, struct audit_parent, wdata);
+
+ mutex_lock(&audit_filter_mutex);
+
+ /* parent was moved before we took audit_filter_mutex */
+ if (parent->flags & AUDIT_PARENT_INVALID)
+ ret = -ENOENT;
+ else
+ audit_add_to_parent(krule, parent);
+
+ /* match get in audit_init_parent or inotify_find_watch */
+ put_inotify_watch(&parent->wdata);
+ return ret;
+}
+
+/* Add rule to given filterlist if not a duplicate. */
static inline int audit_add_rule(struct audit_entry *entry,
- struct list_head *list)
+ struct list_head *list)
{
struct audit_entry *e;
+ struct audit_field *inode_f = entry->rule.inode_f;
+ struct audit_watch *watch = entry->rule.watch;
+ struct nameidata *ndp, *ndw;
+ int h, err, putnd_needed = 0;
+
+ if (inode_f) {
+ h = audit_hash_ino(inode_f->val);
+ list = &audit_inode_hash[h];
+ }
+
+ mutex_lock(&audit_filter_mutex);
+ e = audit_find_rule(entry, list);
+ mutex_unlock(&audit_filter_mutex);
+ if (e) {
+ err = -EEXIST;
+ goto error;
+ }
- /* Do not use the _rcu iterator here, since this is the only
- * addition routine. */
- list_for_each_entry(e, list, list) {
- if (!audit_compare_rule(&entry->rule, &e->rule))
- return -EEXIST;
+ /* Avoid calling path_lookup under audit_filter_mutex. */
+ if (watch) {
+ err = audit_get_nd(watch->path, &ndp, &ndw);
+ if (err)
+ goto error;
+ putnd_needed = 1;
+ }
+
+ mutex_lock(&audit_filter_mutex);
+ if (watch) {
+ /* audit_filter_mutex is dropped and re-taken during this call */
+ err = audit_add_watch(&entry->rule, ndp, ndw);
+ if (err) {
+ mutex_unlock(&audit_filter_mutex);
+ goto error;
+ }
+ h = audit_hash_ino((u32)watch->ino);
+ list = &audit_inode_hash[h];
}
if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
@@ -488,27 +1047,77 @@ static inline int audit_add_rule(struct audit_entry *entry,
} else {
list_add_tail_rcu(&entry->list, list);
}
+ mutex_unlock(&audit_filter_mutex);
- return 0;
+ if (putnd_needed)
+ audit_put_nd(ndp, ndw);
+
+ return 0;
+
+error:
+ if (putnd_needed)
+ audit_put_nd(ndp, ndw);
+ if (watch)
+ audit_put_watch(watch); /* tmp watch, matches initial get */
+ return err;
}
-/* Remove an existing rule from filterlist. Protected by
- * audit_netlink_mutex. */
+/* Remove an existing rule from filterlist. */
static inline int audit_del_rule(struct audit_entry *entry,
struct list_head *list)
{
struct audit_entry *e;
+ struct audit_field *inode_f = entry->rule.inode_f;
+ struct audit_watch *watch, *tmp_watch = entry->rule.watch;
+ LIST_HEAD(inotify_list);
+ int h, ret = 0;
+
+ if (inode_f) {
+ h = audit_hash_ino(inode_f->val);
+ list = &audit_inode_hash[h];
+ }
- /* Do not use the _rcu iterator here, since this is the only
- * deletion routine. */
- list_for_each_entry(e, list, list) {
- if (!audit_compare_rule(&entry->rule, &e->rule)) {
- list_del_rcu(&e->list);
- call_rcu(&e->rcu, audit_free_rule_rcu);
- return 0;
+ mutex_lock(&audit_filter_mutex);
+ e = audit_find_rule(entry, list);
+ if (!e) {
+ mutex_unlock(&audit_filter_mutex);
+ ret = -ENOENT;
+ goto out;
+ }
+
+ watch = e->rule.watch;
+ if (watch) {
+ struct audit_parent *parent = watch->parent;
+
+ list_del(&e->rule.rlist);
+
+ if (list_empty(&watch->rules)) {
+ audit_remove_watch(watch);
+
+ if (list_empty(&parent->watches)) {
+ /* Put parent on the inotify un-registration
+ * list. Grab a reference before releasing
+ * audit_filter_mutex, to be released in
+ * audit_inotify_unregister(). */
+ list_add(&parent->ilist, &inotify_list);
+ get_inotify_watch(&parent->wdata);
+ }
}
}
- return -ENOENT; /* No matching rule */
+
+ list_del_rcu(&e->list);
+ call_rcu(&e->rcu, audit_free_rule_rcu);
+
+ mutex_unlock(&audit_filter_mutex);
+
+ if (!list_empty(&inotify_list))
+ audit_inotify_unregister(&inotify_list);
+
+out:
+ if (tmp_watch)
+ audit_put_watch(tmp_watch); /* match initial get */
+
+ return ret;
}
/* List rules using struct audit_rule. Exists for backward
@@ -519,8 +1128,8 @@ static void audit_list(int pid, int seq, struct sk_buff_head *q)
struct audit_entry *entry;
int i;
- /* The *_rcu iterators not needed here because we are
- always called with audit_netlink_mutex held. */
+ /* This is a blocking read, so use audit_filter_mutex instead of rcu
+ * iterator to sync with list writers. */
for (i=0; i<AUDIT_NR_FILTERS; i++) {
list_for_each_entry(entry, &audit_filter_list[i], list) {
struct audit_rule *rule;
@@ -535,6 +1144,20 @@ static void audit_list(int pid, int seq, struct sk_buff_head *q)
kfree(rule);
}
}
+ for (i = 0; i < AUDIT_INODE_BUCKETS; i++) {
+ list_for_each_entry(entry, &audit_inode_hash[i], list) {
+ struct audit_rule *rule;
+
+ rule = audit_krule_to_rule(&entry->rule);
+ if (unlikely(!rule))
+ break;
+ skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
+ rule, sizeof(*rule));
+ if (skb)
+ skb_queue_tail(q, skb);
+ kfree(rule);
+ }
+ }
skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
if (skb)
skb_queue_tail(q, skb);
@@ -547,8 +1170,8 @@ static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
struct audit_entry *e;
int i;
- /* The *_rcu iterators not needed here because we are
- always called with audit_netlink_mutex held. */
+ /* This is a blocking read, so use audit_filter_mutex instead of rcu
+ * iterator to sync with list writers. */
for (i=0; i<AUDIT_NR_FILTERS; i++) {
list_for_each_entry(e, &audit_filter_list[i], list) {
struct audit_rule_data *data;
@@ -557,7 +1180,21 @@ static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
if (unlikely(!data))
break;
skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
- data, sizeof(*data));
+ data, sizeof(*data) + data->buflen);
+ if (skb)
+ skb_queue_tail(q, skb);
+ kfree(data);
+ }
+ }
+ for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
+ list_for_each_entry(e, &audit_inode_hash[i], list) {
+ struct audit_rule_data *data;
+
+ data = audit_krule_to_data(&e->rule);
+ if (unlikely(!data))
+ break;
+ skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
+ data, sizeof(*data) + data->buflen);
if (skb)
skb_queue_tail(q, skb);
kfree(data);
@@ -602,10 +1239,12 @@ int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
dest->pid = pid;
skb_queue_head_init(&dest->q);
+ mutex_lock(&audit_filter_mutex);
if (type == AUDIT_LIST)
audit_list(pid, seq, &dest->q);
else
audit_list_rules(pid, seq, &dest->q);
+ mutex_unlock(&audit_filter_mutex);
tsk = kthread_run(audit_send_list, dest, "audit_send_list");
if (IS_ERR(tsk)) {
@@ -625,6 +1264,7 @@ int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
err = audit_add_rule(entry,
&audit_filter_list[entry->rule.listnr]);
+
if (sid) {
char *ctx = NULL;
u32 len;
@@ -705,7 +1345,39 @@ int audit_comparator(const u32 left, const u32 op, const u32 right)
return 0;
}
+/* Compare given dentry name with last component in given path,
+ * return of 0 indicates a match. */
+int audit_compare_dname_path(const char *dname, const char *path)
+{
+ int dlen, plen;
+ const char *p;
+
+ if (!dname || !path)
+ return 1;
+
+ dlen = strlen(dname);
+ plen = strlen(path);
+ if (plen < dlen)
+ return 1;
+
+ /* disregard trailing slashes */
+ p = path + plen - 1;
+ while ((*p == '/') && (p > path))
+ p--;
+
+ /* find last path component */
+ p = p - dlen + 1;
+ if (p < path)
+ return 1;
+ else if (p > path) {
+ if (*--p != '/')
+ return 1;
+ else
+ p++;
+ }
+ return strncmp(p, dname, dlen);
+}
static int audit_filter_user_rules(struct netlink_skb_parms *cb,
struct audit_krule *rule,
@@ -818,32 +1490,65 @@ static inline int audit_rule_has_selinux(struct audit_krule *rule)
int selinux_audit_rule_update(void)
{
struct audit_entry *entry, *n, *nentry;
+ struct audit_watch *watch;
int i, err = 0;
- /* audit_netlink_mutex synchronizes the writers */
- mutex_lock(&audit_netlink_mutex);
+ /* audit_filter_mutex synchronizes the writers */
+ mutex_lock(&audit_filter_mutex);
for (i = 0; i < AUDIT_NR_FILTERS; i++) {
list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) {
if (!audit_rule_has_selinux(&entry->rule))
continue;
- nentry = audit_dupe_rule(&entry->rule);
+ watch = entry->rule.watch;
+ nentry = audit_dupe_rule(&entry->rule, watch);
if (unlikely(IS_ERR(nentry))) {
/* save the first error encountered for the
* return value */
if (!err)
err = PTR_ERR(nentry);
audit_panic("error updating selinux filters");
+ if (watch)
+ list_del(&entry->rule.rlist);
list_del_rcu(&entry->list);
} else {
+ if (watch) {
+ list_add(&nentry->rule.rlist,
+ &watch->rules);
+ list_del(&entry->rule.rlist);
+ }
list_replace_rcu(&entry->list, &nentry->list);
}
call_rcu(&entry->rcu, audit_free_rule_rcu);
}
}
- mutex_unlock(&audit_netlink_mutex);
+ mutex_unlock(&audit_filter_mutex);
return err;
}
+
+/* Update watch data in audit rules based on inotify events. */
+void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
+ u32 cookie, const char *dname, struct inode *inode)
+{
+ struct audit_parent *parent;
+
+ parent = container_of(i_watch, struct audit_parent, wdata);
+
+ if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
+ audit_update_watch(parent, dname, inode->i_sb->s_dev,
+ inode->i_ino, 0);
+ else if (mask & (IN_DELETE|IN_MOVED_FROM))
+ audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
+ /* inotify automatically removes the watch and sends IN_IGNORED */
+ else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
+ audit_remove_parent_watches(parent);
+ /* inotify does not remove the watch, so remove it manually */
+ else if(mask & IN_MOVE_SELF) {
+ audit_remove_parent_watches(parent);
+ inotify_remove_watch_locked(audit_ih, i_watch);
+ } else if (mask & IN_IGNORED)
+ put_inotify_watch(i_watch);
+}
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 14e295a4..174a3f6 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -200,12 +200,13 @@ struct audit_context {
#endif
};
-
+/* Determine if any context name data matches a rule's watch data */
/* Compare a task_struct with an audit_rule. Return 1 on match, 0
* otherwise. */
static int audit_filter_rules(struct task_struct *tsk,
struct audit_krule *rule,
struct audit_context *ctx,
+ struct audit_names *name,
enum audit_state *state)
{
int i, j, need_sid = 1;
@@ -268,7 +269,10 @@ static int audit_filter_rules(struct task_struct *tsk,
}
break;
case AUDIT_DEVMAJOR:
- if (ctx) {
+ if (name)
+ result = audit_comparator(MAJOR(name->dev),
+ f->op, f->val);
+ else if (ctx) {
for (j = 0; j < ctx->name_count; j++) {
if (audit_comparator(MAJOR(ctx->names[j].dev), f->op, f->val)) {
++result;
@@ -278,7 +282,10 @@ static int audit_filter_rules(struct task_struct *tsk,
}
break;
case AUDIT_DEVMINOR:
- if (ctx) {
+ if (name)
+ result = audit_comparator(MINOR(name->dev),
+ f->op, f->val);
+ else if (ctx) {
for (j = 0; j < ctx->name_count; j++) {
if (audit_comparator(MINOR(ctx->names[j].dev), f->op, f->val)) {
++result;
@@ -288,7 +295,10 @@ static int audit_filter_rules(struct task_struct *tsk,
}
break;
case AUDIT_INODE:
- if (ctx) {
+ if (name)
+ result = (name->ino == f->val ||
+ name->pino == f->val);
+ else if (ctx) {
for (j = 0; j < ctx->name_count; j++) {
if (audit_comparator(ctx->names[j].ino, f->op, f->val) ||
audit_comparator(ctx->names[j].pino, f->op, f->val)) {
@@ -298,6 +308,12 @@ static int audit_filter_rules(struct task_struct *tsk,
}
}
break;
+ case AUDIT_WATCH:
+ if (name && rule->watch->ino != (unsigned long)-1)
+ result = (name->dev == rule->watch->dev &&
+ (name->ino == rule->watch->ino ||
+ name->pino == rule->watch->ino));
+ break;
case AUDIT_LOGINUID:
result = 0;
if (ctx)
@@ -354,7 +370,7 @@ static enum audit_state audit_filter_task(struct task_struct *tsk)
rcu_read_lock();
list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) {
- if (audit_filter_rules(tsk, &e->rule, NULL, &state)) {
+ if (audit_filter_rules(tsk, &e->rule, NULL, NULL, &state)) {
rcu_read_unlock();
return state;
}
@@ -384,8 +400,9 @@ static enum audit_state audit_filter_syscall(struct task_struct *tsk,
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)) {
+ if ((e->rule.mask[word] & bit) == bit &&
+ audit_filter_rules(tsk, &e->rule, ctx, NULL,
+ &state)) {
rcu_read_unlock();
return state;
}
@@ -395,6 +412,49 @@ static enum audit_state audit_filter_syscall(struct task_struct *tsk,
return AUDIT_BUILD_CONTEXT;
}
+/* At syscall exit time, this filter is called if any audit_names[] have been
+ * collected during syscall processing. We only check rules in sublists at hash
+ * 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)
+{
+ int i;
+ struct audit_entry *e;
+ enum audit_state state;
+
+ if (audit_pid && tsk->tgid == audit_pid)
+ return AUDIT_DISABLED;
+
+ rcu_read_lock();
+ for (i = 0; i < ctx->name_count; i++) {
+ int word = AUDIT_WORD(ctx->major);
+ int bit = AUDIT_BIT(ctx->major);
+ struct audit_names *n = &ctx->names[i];
+ int h = audit_hash_ino((u32)n->ino);
+ struct list_head *list = &audit_inode_hash[h];
+
+ if (list_empty(list))
+ continue;
+
+ list_for_each_entry_rcu(e, list, list) {
+ if ((e->rule.mask[word] & bit) == bit &&
+ audit_filter_rules(tsk, &e->rule, ctx, n, &state)) {
+ rcu_read_unlock();
+ return state;
+ }
+ }
+ }
+ rcu_read_unlock();
+ return AUDIT_BUILD_CONTEXT;
+}
+
+void audit_set_auditable(struct audit_context *ctx)
+{
+ ctx->auditable = 1;
+}
+
static inline struct audit_context *audit_get_context(struct task_struct *tsk,
int return_valid,
int return_code)
@@ -408,11 +468,20 @@ 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_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;
+
}
+get_context:
context->pid = tsk->pid;
context->ppid = sys_getppid(); /* sic. tsk == current in all cases */
context->uid = tsk->uid;
@@ -1142,37 +1211,20 @@ void __audit_inode_child(const char *dname, const struct inode *inode,
return;
/* determine matching parent */
- if (dname)
- for (idx = 0; idx < context->name_count; idx++)
- if (context->names[idx].pino == pino) {
- const char *n;
- const char *name = context->names[idx].name;
- int dlen = strlen(dname);
- int nlen = name ? strlen(name) : 0;
-
- if (nlen < dlen)
- continue;
-
- /* disregard trailing slashes */
- n = name + nlen - 1;
- while ((*n == '/') && (n > name))
- n--;
-
- /* find last path component */
- n = n - dlen + 1;
- if (n < name)
- continue;
- else if (n > name) {
- if (*--n != '/')
- continue;
- else
- n++;
- }
+ if (!dname)
+ goto no_match;
+ for (idx = 0; idx < context->name_count; idx++)
+ if (context->names[idx].pino == pino) {
+ const char *name = context->names[idx].name;
- if (strncmp(n, dname, dlen) == 0)
- goto update_context;
- }
+ if (!name)
+ continue;
+
+ if (audit_compare_dname_path(dname, name) == 0)
+ goto update_context;
+ }
+no_match:
/* catch-all in case match not found */
idx = context->name_count++;
context->names[idx].name = NULL;
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