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authorRichard Guy Briggs <rgb@redhat.com>2015-08-05 16:29:37 -0400
committerPaul Moore <pmoore@redhat.com>2015-08-06 16:17:25 -0400
commit34d99af52ad40bd498ba66970579a5bc1fb1a3bc (patch)
treefcab34928eb893eff68506685675420f0afba08e
parent7f49294282c49ef426ed05eb4959728524ba140c (diff)
downloadop-kernel-dev-34d99af52ad40bd498ba66970579a5bc1fb1a3bc.zip
op-kernel-dev-34d99af52ad40bd498ba66970579a5bc1fb1a3bc.tar.gz
audit: implement audit by executable
This adds the ability audit the actions of a not-yet-running process. This patch implements the ability to filter on the executable path. Instead of just hard coding the ino and dev of the executable we care about at the moment the rule is inserted into the kernel, use the new audit_fsnotify infrastructure to manage this dynamically. This means that if the filename does not yet exist but the containing directory does, or if the inode in question is unlinked and creat'd (aka updated) the rule will just continue to work. If the containing directory is moved or deleted or the filesystem is unmounted, the rule is deleted automatically. A future enhancement would be to have the rule survive across directory disruptions. This is a heavily modified version of a patch originally submitted by Eric Paris with some ideas from Peter Moody. Cc: Peter Moody <peter@hda3.com> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Richard Guy Briggs <rgb@redhat.com> [PM: minor whitespace clean to satisfy ./scripts/checkpatch] Signed-off-by: Paul Moore <pmoore@redhat.com>
-rw-r--r--include/linux/audit.h1
-rw-r--r--include/uapi/linux/audit.h5
-rw-r--r--kernel/audit.h4
-rw-r--r--kernel/audit_tree.c2
-rw-r--r--kernel/audit_watch.c31
-rw-r--r--kernel/auditfilter.c53
-rw-r--r--kernel/auditsc.c3
7 files changed, 97 insertions, 2 deletions
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 759feb0..b2abc99 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -62,6 +62,7 @@ struct audit_krule {
struct audit_field *inode_f; /* quick access to an inode field */
struct audit_watch *watch; /* associated watch */
struct audit_tree *tree; /* associated watched tree */
+ struct audit_fsnotify_mark *exe;
struct list_head rlist; /* entry in audit_{watch,tree}.rules list */
struct list_head list; /* for AUDIT_LIST* purposes only */
u64 prio;
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index d3475e1..f6ff62c 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -266,6 +266,7 @@
#define AUDIT_OBJ_UID 109
#define AUDIT_OBJ_GID 110
#define AUDIT_FIELD_COMPARE 111
+#define AUDIT_EXE 112
#define AUDIT_ARG0 200
#define AUDIT_ARG1 (AUDIT_ARG0+1)
@@ -324,8 +325,10 @@ enum {
#define AUDIT_FEATURE_BITMAP_BACKLOG_LIMIT 0x00000001
#define AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_TIME 0x00000002
+#define AUDIT_FEATURE_BITMAP_EXECUTABLE_PATH 0x00000004
#define AUDIT_FEATURE_BITMAP_ALL (AUDIT_FEATURE_BITMAP_BACKLOG_LIMIT | \
- AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_TIME)
+ AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_TIME | \
+ AUDIT_FEATURE_BITMAP_EXECUTABLE_PATH)
/* deprecated: AUDIT_VERSION_* */
#define AUDIT_VERSION_LATEST AUDIT_FEATURE_BITMAP_ALL
diff --git a/kernel/audit.h b/kernel/audit.h
index 7102d53..24ec861 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -274,6 +274,8 @@ extern char *audit_mark_path(struct audit_fsnotify_mark *mark);
extern void audit_remove_mark(struct audit_fsnotify_mark *audit_mark);
extern void audit_remove_mark_rule(struct audit_krule *krule);
extern int audit_mark_compare(struct audit_fsnotify_mark *mark, unsigned long ino, dev_t dev);
+extern int audit_dupe_exe(struct audit_krule *new, struct audit_krule *old);
+extern int audit_exe_compare(struct task_struct *tsk, struct audit_fsnotify_mark *mark);
#else
#define audit_put_watch(w) {}
@@ -289,6 +291,8 @@ extern int audit_mark_compare(struct audit_fsnotify_mark *mark, unsigned long in
#define audit_remove_mark(m)
#define audit_remove_mark_rule(k)
#define audit_mark_compare(m, i, d) 0
+#define audit_exe_compare(t, m) (-EINVAL)
+#define audit_dupe_exe(n, o) (-EINVAL)
#endif /* CONFIG_AUDIT_WATCH */
#ifdef CONFIG_AUDIT_TREE
diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c
index 2e0c974..f4172250 100644
--- a/kernel/audit_tree.c
+++ b/kernel/audit_tree.c
@@ -478,6 +478,8 @@ static void kill_rules(struct audit_tree *tree)
if (rule->tree) {
/* not a half-baked one */
audit_tree_log_remove_rule(rule);
+ if (entry->rule.exe)
+ audit_remove_mark(entry->rule.exe);
rule->tree = NULL;
list_del_rcu(&entry->list);
list_del(&entry->rule.list);
diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
index 645c688..27ef8dc 100644
--- a/kernel/audit_watch.c
+++ b/kernel/audit_watch.c
@@ -312,6 +312,8 @@ static void audit_update_watch(struct audit_parent *parent,
list_replace(&oentry->rule.list,
&nentry->rule.list);
}
+ if (oentry->rule.exe)
+ audit_remove_mark(oentry->rule.exe);
audit_watch_log_rule_change(r, owatch, "updated_rules");
@@ -342,6 +344,8 @@ static void audit_remove_parent_watches(struct audit_parent *parent)
list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
e = container_of(r, struct audit_entry, rule);
audit_watch_log_rule_change(r, w, "remove_rule");
+ if (e->rule.exe)
+ audit_remove_mark(e->rule.exe);
list_del(&r->rlist);
list_del(&r->list);
list_del_rcu(&e->list);
@@ -514,3 +518,30 @@ static int __init audit_watch_init(void)
return 0;
}
device_initcall(audit_watch_init);
+
+int audit_dupe_exe(struct audit_krule *new, struct audit_krule *old)
+{
+ struct audit_fsnotify_mark *audit_mark;
+ char *pathname;
+
+ pathname = kstrdup(audit_mark_path(old->exe), GFP_KERNEL);
+ if (!pathname)
+ return -ENOMEM;
+
+ audit_mark = audit_alloc_mark(new, pathname, strlen(pathname));
+ if (IS_ERR(audit_mark)) {
+ kfree(pathname);
+ return PTR_ERR(audit_mark);
+ }
+ new->exe = audit_mark;
+
+ return 0;
+}
+
+int audit_exe_compare(struct task_struct *tsk, struct audit_fsnotify_mark *mark)
+{
+ unsigned long ino = tsk->mm->exe_file->f_inode->i_ino;
+ dev_t dev = tsk->mm->exe_file->f_inode->i_sb->s_dev;
+
+ return audit_mark_compare(mark, ino, dev);
+}
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index b4d8c36..7714d93 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -405,6 +405,12 @@ static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
if (f->val > AUDIT_MAX_FIELD_COMPARE)
return -EINVAL;
break;
+ case AUDIT_EXE:
+ if (f->op != Audit_equal)
+ return -EINVAL;
+ if (entry->rule.listnr != AUDIT_FILTER_EXIT)
+ return -EINVAL;
+ break;
};
return 0;
}
@@ -419,6 +425,7 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
size_t remain = datasz - sizeof(struct audit_rule_data);
int i;
char *str;
+ struct audit_fsnotify_mark *audit_mark;
entry = audit_to_entry_common(data);
if (IS_ERR(entry))
@@ -539,6 +546,24 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
entry->rule.buflen += f->val;
entry->rule.filterkey = str;
break;
+ case AUDIT_EXE:
+ if (entry->rule.exe || f->val > PATH_MAX)
+ goto exit_free;
+ str = audit_unpack_string(&bufp, &remain, f->val);
+ if (IS_ERR(str)) {
+ err = PTR_ERR(str);
+ goto exit_free;
+ }
+ entry->rule.buflen += f->val;
+
+ audit_mark = audit_alloc_mark(&entry->rule, str, f->val);
+ if (IS_ERR(audit_mark)) {
+ kfree(str);
+ err = PTR_ERR(audit_mark);
+ goto exit_free;
+ }
+ entry->rule.exe = audit_mark;
+ break;
}
}
@@ -551,6 +576,8 @@ exit_nofree:
exit_free:
if (entry->rule.tree)
audit_put_tree(entry->rule.tree); /* that's the temporary one */
+ if (entry->rule.exe)
+ audit_remove_mark(entry->rule.exe); /* that's the template one */
audit_free_rule(entry);
return ERR_PTR(err);
}
@@ -615,6 +642,10 @@ static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
data->buflen += data->values[i] =
audit_pack_string(&bufp, krule->filterkey);
break;
+ case AUDIT_EXE:
+ data->buflen += data->values[i] =
+ audit_pack_string(&bufp, audit_mark_path(krule->exe));
+ break;
case AUDIT_LOGINUID_SET:
if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
data->fields[i] = AUDIT_LOGINUID;
@@ -678,6 +709,12 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
if (strcmp(a->filterkey, b->filterkey))
return 1;
break;
+ case AUDIT_EXE:
+ /* both paths exist based on above type compare */
+ if (strcmp(audit_mark_path(a->exe),
+ audit_mark_path(b->exe)))
+ return 1;
+ break;
case AUDIT_UID:
case AUDIT_EUID:
case AUDIT_SUID:
@@ -799,8 +836,14 @@ struct audit_entry *audit_dupe_rule(struct audit_krule *old)
err = -ENOMEM;
else
new->filterkey = fk;
+ break;
+ case AUDIT_EXE:
+ err = audit_dupe_exe(new, old);
+ break;
}
if (err) {
+ if (new->exe)
+ audit_remove_mark(new->exe);
audit_free_rule(entry);
return ERR_PTR(err);
}
@@ -963,6 +1006,9 @@ int audit_del_rule(struct audit_entry *entry)
if (e->rule.tree)
audit_remove_tree_rule(&e->rule);
+ if (e->rule.exe)
+ audit_remove_mark_rule(&e->rule);
+
#ifdef CONFIG_AUDITSYSCALL
if (!dont_count)
audit_n_rules--;
@@ -1067,8 +1113,11 @@ int audit_rule_change(int type, __u32 portid, int seq, void *data,
WARN_ON(1);
}
- if (err || type == AUDIT_DEL_RULE)
+ if (err || type == AUDIT_DEL_RULE) {
+ if (entry->rule.exe)
+ audit_remove_mark(entry->rule.exe);
audit_free_rule(entry);
+ }
return err;
}
@@ -1360,6 +1409,8 @@ static int update_lsm_rule(struct audit_krule *r)
return 0;
nentry = audit_dupe_rule(r);
+ if (entry->rule.exe)
+ audit_remove_mark(entry->rule.exe);
if (IS_ERR(nentry)) {
/* save the first error encountered for the
* return value */
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index ea3fe2b..9b56b7a 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -466,6 +466,9 @@ static int audit_filter_rules(struct task_struct *tsk,
result = audit_comparator(ctx->ppid, f->op, f->val);
}
break;
+ case AUDIT_EXE:
+ result = audit_exe_compare(tsk, rule->exe);
+ break;
case AUDIT_UID:
result = audit_uid_comparator(cred->uid, f->op, f->uid);
break;
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