TOMOYO: Allow using executable's realpath and symlink's target as conditions.

This patch adds support for permission checks using executable file's realpath
upon execve() and symlink's target upon symlink(). Hooks are in the last patch
of this pathset.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 21 insertions, 0 deletions

diff --git a/security/tomoyo/audit.c b/security/tomoyo/audit.c
index 4973edd40718..b33a20accbef 100644
--- a/security/tomoyo/audit.c
+++ b/security/tomoyo/audit.c
@@ -140,6 +140,8 @@ char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt,
 {
 	char *buf = NULL;
 	const char *header = NULL;
+	char *realpath = NULL;
+	const char *symlink = NULL;
 	int pos;
 	const char *domainname = r->domain->domainname->name;
 	header = tomoyo_print_header(r);
@@ -147,15 +149,34 @@ char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt,
 		return NULL;
 	/* +10 is for '\n' etc. and '\0'. */
 	len += strlen(domainname) + strlen(header) + 10;
+	if (r->ee) {
+		struct file *file = r->ee->bprm->file;
+		realpath = tomoyo_realpath_from_path(&file->f_path);
+		if (!realpath)
+			goto out;
+		/* +80 is for " exec={ realpath=\"%s\" }" */
+		len += strlen(realpath) + 80;
+	} else if (r->obj && r->obj->symlink_target) {
+		symlink = r->obj->symlink_target->name;
+		/* +18 is for " symlink.target=\"%s\"" */
+		len += 18 + strlen(symlink);
+	}
 	len = tomoyo_round2(len);
 	buf = kzalloc(len, GFP_NOFS);
 	if (!buf)
 		goto out;
 	len--;
 	pos = snprintf(buf, len, "%s", header);
+	if (realpath) {
+		pos += snprintf(buf + pos, len - pos,
+				" exec={ realpath=\"%s\" }", realpath);
+	} else if (symlink)
+		pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"",
+				symlink);
 	pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname);
 	vsnprintf(buf + pos, len - pos, fmt, args);
 out:
+	kfree(realpath);
 	kfree(header);
 	return buf;
 }