From 05bfd66693b22fabaccfb75ec67b1d7f521b6a83 Mon Sep 17 00:00:00 2001
From: "Todd C. Miller" <Todd.Miller@courtesan.com>
Date: Sun, 25 Sep 2011 06:35:40 -0400
Subject: [PATCH] If the invoking user cannot be resolved by uid fake the
 struct passwd and store it in the cache so we can delref it on exit.

---
 plugins/sudoers/pwutil.c  | 18 +++++++++++++++---
 plugins/sudoers/sudoers.c | 17 ++++++-----------
 plugins/sudoers/sudoers.h |  1 +
 3 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/plugins/sudoers/pwutil.c b/plugins/sudoers/pwutil.c
index fc45787e7..7d719e10a 100644
--- a/plugins/sudoers/pwutil.c
+++ b/plugins/sudoers/pwutil.c
@@ -312,10 +312,10 @@ done:
 }
 
 /*
- * Take a uid in string form "#123" and return a faked up passwd struct.
+ * Take a user, uid and gid and return a faked up passwd struct.
  */
 struct passwd *
-sudo_fakepwnam(const char *user, gid_t gid)
+sudo_fakepwnamid(const char *user, uid_t uid, gid_t gid)
 {
     struct cache_item *item;
     struct passwd *pw;
@@ -332,7 +332,7 @@ sudo_fakepwnam(const char *user, gid_t gid)
 	item = emalloc(len);
 	zero_bytes(item, sizeof(*item) + sizeof(*pw));
 	pw = (struct passwd *) ((char *)item + sizeof(*item));
-	pw->pw_uid = (uid_t) atoi(user + 1);
+	pw->pw_uid = uid;
 	pw->pw_gid = gid;
 	pw->pw_name = (char *)pw + sizeof(struct passwd);
 	memcpy(pw->pw_name, user, namelen + 1);
@@ -367,6 +367,18 @@ sudo_fakepwnam(const char *user, gid_t gid)
     return pw;
 }
 
+/*
+ * Take a uid in string form "#123" and return a faked up passwd struct.
+ */
+struct passwd *
+sudo_fakepwnam(const char *user, gid_t gid)
+{
+    uid_t uid;
+
+    uid = (uid_t) atoi(user + 1);
+    return sudo_fakepwnamid(user, uid, gid);
+}
+
 void
 sudo_setpwent(void)
 {
diff --git a/plugins/sudoers/sudoers.c b/plugins/sudoers/sudoers.c
index 36a19f4f5..9f27fe812 100644
--- a/plugins/sudoers/sudoers.c
+++ b/plugins/sudoers/sudoers.c
@@ -792,23 +792,18 @@ init_vars(char * const envp[])
      * if necessary.  It is assumed that euid is 0 at this point so we
      * can read the shadow passwd file if necessary.
      */
-    if ((sudo_user.pw = sudo_getpwnam(user_name)) == NULL) {
-	static struct passwd pw;
-
-	/* Create a fake struct passwd for log_error(). */
-	memset(&pw, 0, sizeof(pw));
-	pw.pw_uid = getuid();
-	pw.pw_name = user_name;
-	sudo_user.pw = &pw;
-
+    if ((sudo_user.pw = sudo_getpwuid(user_uid)) == NULL) {
 	/*
 	 * It is not unusual for users to place "sudo -k" in a .logout
 	 * file which can cause sudo to be run during reboot after the
 	 * YP/NIS/NIS+/LDAP/etc daemon has died.
 	 */
 	if (sudo_mode == MODE_KILL || sudo_mode == MODE_INVALIDATE)
-	    errorx(1, _("unknown user: %s"), user_name);
-	log_error(0, _("unknown user: %s"), user_name);
+	    errorx(1, _("unknown uid: %u"), (unsigned int) user_uid);
+
+	/* Need to make a fake struct passwd for the call to log_error(). */
+	sudo_user.pw = sudo_fakepwnamid(user_name, user_uid, user_gid);
+	log_error(0, _("unknown uid: %u"), (unsigned int) user_uid);
 	/* NOTREACHED */
     }
 
diff --git a/plugins/sudoers/sudoers.h b/plugins/sudoers/sudoers.h
index 6e21d9684..c88e90b13 100644
--- a/plugins/sudoers/sudoers.h
+++ b/plugins/sudoers/sudoers.h
@@ -268,6 +268,7 @@ void sudo_endspent(void);
 struct group_list *get_group_list(struct passwd *pw);
 void set_group_list(const char *, GETGROUPS_T *gids, int ngids);
 struct passwd *sudo_getpwnam(const char *);
+struct passwd *sudo_fakepwnamid(const char *user, uid_t uid, gid_t gid);
 struct passwd *sudo_fakepwnam(const char *, gid_t);
 struct passwd *sudo_getpwuid(uid_t);
 struct group *sudo_getgrnam(const char *);