File sudo-CVE-2021-3156.patch of Package sudo

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File sudo-CVE-2021-3156.patch of Package sudo (Revision ea169a758f4f594a82e6b447d8fcf12e)

Currently displaying revision ea169a758f4f594a82e6b447d8fcf12e , Show latest

# HG changeset patch
# Parent  2dbbab94d4b60ae05cb2aebf5bad1b9e18cdbb11
Reset valid_flags to MODE_NONINTERACTIVE for sudoedit.
This is consistent with how the -e option is handled.
Also reject -H and -P flags for sudoedit as was done in sudo 1.7.
Found by Qualys.

diff --git a/plugins/sudoers/policy.c b/plugins/sudoers/policy.c
index 09cf401..e2dd7c8 100644
--- a/plugins/sudoers/policy.c
+++ b/plugins/sudoers/policy.c
@@ -98,10 +98,11 @@ parse_bool(const char *line, int varlen, int *flags, int fval)
 int
 sudoers_policy_deserialize_info(void *v, char **runas_user, char **runas_group)
 {
+    const int edit_mask = MODE_EDIT|MODE_IGNORE_TICKET|MODE_NONINTERACTIVE;
     struct sudoers_policy_open_info *info = v;
-    char * const *cur;
     const char *p, *errstr, *groups = NULL;
     const char *remhost = NULL;
+    char * const *cur;
     bool uid_set = false, gid_set = false;
     int flags = 0;
     debug_decl(sudoers_policy_deserialize_info, SUDOERS_DEBUG_PLUGIN)
@@ -331,6 +332,12 @@ sudoers_policy_deserialize_info(void *v, char **runas_user, char **runas_group)
 #endif
     }
 
+    /* Sudo front-end should restrict mode flags for sudoedit. */
+    if (ISSET(flags, MODE_EDIT) && (flags & edit_mask) != flags) {
+	    sudo_warnx(U_("invalid mode flags from sudo front end: 0x%x"), flags);
+   	  goto bad;
+    }
+
     user_umask = (mode_t)-1;
     for (cur = info->user_info; *cur != NULL; cur++) {
 	if (MATCHES(*cur, "user=")) {
diff --git a/plugins/sudoers/sudoers.c b/plugins/sudoers/sudoers.c
index 1267949..5f10653 100644
--- a/plugins/sudoers/sudoers.c
+++ b/plugins/sudoers/sudoers.c
@@ -404,7 +404,7 @@ sudoers_policy_main(int argc, char * const argv[], int pwflag, char *env_add[],
 
     /* If run as root with SUDO_USER set, set sudo_user.pw to that user. */
     /* XXX - causes confusion when root is not listed in sudoers */
-    if (sudo_mode & (MODE_RUN | MODE_EDIT) && prev_user != NULL) {
+    if (ISSET(sudo_mode, MODE_RUN|MODE_EDIT) && prev_user != NULL) {
 	if (user_uid == 0 && strcmp(prev_user, "root") != 0) {
 	    struct passwd *pw;
 
@@ -784,8 +784,8 @@ set_cmnd(void)
     if (user_cmnd == NULL)
 	user_cmnd = NewArgv[0];
 
-    if (sudo_mode & (MODE_RUN | MODE_EDIT | MODE_CHECK)) {
-	if (ISSET(sudo_mode, MODE_RUN | MODE_CHECK)) {
+  if (ISSET(sudo_mode, MODE_RUN|MODE_EDIT|MODE_CHECK)) {
+	if (!ISSET(sudo_mode, MODE_EDIT)) {
 	    if (def_secure_path && !user_is_exempt())
 		path = def_secure_path;
 	    if (!set_perms(PERM_RUNAS))
@@ -823,7 +823,8 @@ set_cmnd(void)
 		sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
 		debug_return_int(-1);
 	    }
-	    if (ISSET(sudo_mode, MODE_SHELL|MODE_LOGIN_SHELL)) {
+	    if (ISSET(sudo_mode, MODE_SHELL|MODE_LOGIN_SHELL) &&
+		    ISSET(sudo_mode, MODE_RUN)) {
 		/*
 		 * When running a command via a shell, the sudo front-end
 		 * escapes potential meta chars.  We unescape non-spaces
@@ -831,10 +832,22 @@ set_cmnd(void)
 		 */
 		for (to = user_args, av = NewArgv + 1; (from = *av); av++) {
 		    while (*from) {
-			if (from[0] == '\\' && !isspace((unsigned char)from[1]))
+			if (from[0] == '\\' && from[1] != '\0' &&
+				!isspace((unsigned char)from[1])) {
 			    from++;
+			}
+			if (size - (to - user_args) < 1) {
+			    sudo_warnx(U_("internal error, %s overflow"),
+				__func__);
+			    debug_return_int(NOT_FOUND_ERROR);
+			}
 			*to++ = *from++;
 		    }
+		    if (size - (to - user_args) < 1) {
+			sudo_warnx(U_("internal error, %s overflow"),
+			    __func__);
+			debug_return_int(NOT_FOUND_ERROR);
+		    }
 		    *to++ = ' ';
 		}
 		*--to = '\0';
diff --git a/plugins/sudoers/timestamp.c b/plugins/sudoers/timestamp.c
index 5930103..ea81c3e 100644
--- a/plugins/sudoers/timestamp.c
+++ b/plugins/sudoers/timestamp.c
@@ -650,8 +650,8 @@ timestamp_lock(void *vcookie, struct passwd *pw)
     } else if (entry.type != TS_LOCKEXCL) {
 	/* Old sudo record, convert it to TS_LOCKEXCL. */
 	entry.type = TS_LOCKEXCL;
-	memset((char *)&entry + offsetof(struct timestamp_entry, type), 0,
-	    nread - offsetof(struct timestamp_entry, type));
+  memset((char *)&entry + offsetof(struct timestamp_entry, flags), 0,
+		nread - offsetof(struct timestamp_entry, flags));
 	if (ts_write(cookie->fd, cookie->fname, &entry, 0) == -1)
 	    debug_return_bool(false);
     }
diff --git a/src/parse_args.c b/src/parse_args.c
index d9bbe06..5250f23 100644
--- a/src/parse_args.c
+++ b/src/parse_args.c
@@ -122,6 +122,9 @@ struct environment {
  * Default flags allowed when running a command.
  */
 #define DEFAULT_VALID_FLAGS	(MODE_BACKGROUND|MODE_PRESERVE_ENV|MODE_RESET_HOME|MODE_LOGIN_SHELL|MODE_NONINTERACTIVE|MODE_SHELL)
+#define EDIT_VALID_FLAGS	MODE_NONINTERACTIVE
+#define LIST_VALID_FLAGS	(MODE_NONINTERACTIVE|MODE_LONG_LIST)
+#define VALIDATE_VALID_FLAGS	MODE_NONINTERACTIVE
 
 /* Option number for the --host long option due to ambiguity of the -h flag. */
 #define OPT_HOSTNAME	256
@@ -265,6 +268,7 @@ parse_args(int argc, char **argv, int *nargc, char ***nargv,
 	progname = "sudoedit";
 	mode = MODE_EDIT;
 	sudo_settings[ARG_SUDOEDIT].value = "true";
+	valid_flags = EDIT_VALID_FLAGS;
     }
 
     /* Load local IP addresses and masks. */
@@ -350,7 +354,7 @@ parse_args(int argc, char **argv, int *nargc, char ***nargv,
 			usage_excl(1);
 		    mode = MODE_EDIT;
 		    sudo_settings[ARG_SUDOEDIT].value = "true";
-		    valid_flags = MODE_NONINTERACTIVE;
+		    valid_flags = EDIT_VALID_FLAGS;
 		    break;
 		case 'g':
 		    if (*optarg == '\0')
@@ -360,6 +364,7 @@ parse_args(int argc, char **argv, int *nargc, char ***nargv,
 		    break;
 		case 'H':
 		    sudo_settings[ARG_SET_HOME].value = "true";
+		    SET(flags, MODE_RESET_HOME);
 		    break;
 		case 'h':
 		    if (optarg == NULL) {
@@ -409,7 +414,7 @@ parse_args(int argc, char **argv, int *nargc, char ***nargv,
 			    usage_excl(1);
 		    }
 		    mode = MODE_LIST;
-		    valid_flags = MODE_NONINTERACTIVE|MODE_LONG_LIST;
+		    valid_flags = LIST_VALID_FLAGS;
 		    break;
 		case 'n':
 		    SET(flags, MODE_NONINTERACTIVE);
@@ -417,6 +422,7 @@ parse_args(int argc, char **argv, int *nargc, char ***nargv,
 		    break;
 		case 'P':
 		    sudo_settings[ARG_PRESERVE_GROUPS].value = "true";
+		    SET(flags, MODE_PRESERVE_GROUPS);
 		    break;
 		case 'p':
 		    /* An empty prompt is allowed. */
@@ -460,7 +466,7 @@ parse_args(int argc, char **argv, int *nargc, char ***nargv,
 		    if (mode && mode != MODE_VALIDATE)
 			usage_excl(1);
 		    mode = MODE_VALIDATE;
-		    valid_flags = MODE_NONINTERACTIVE;
+		    valid_flags = VALIDATE_VALID_FLAGS;
 		    break;
 		case 'V':
 		    if (mode && mode != MODE_VERSION)
@@ -487,7 +493,7 @@ parse_args(int argc, char **argv, int *nargc, char ***nargv,
     if (!mode) {
 	/* Defer -k mode setting until we know whether it is a flag or not */
 	if (sudo_settings[ARG_IGNORE_TICKET].value != NULL) {
-	    if (argc == 0 && !(flags & (MODE_SHELL|MODE_LOGIN_SHELL))) {
+	    if (argc == 0 && !ISSET(flags, MODE_SHELL|MODE_LOGIN_SHELL)) {
 		mode = MODE_INVALIDATE;	/* -k by itself */
 		sudo_settings[ARG_IGNORE_TICKET].value = NULL;
 		valid_flags = 0;
@@ -557,16 +563,16 @@ parse_args(int argc, char **argv, int *nargc, char ***nargv,
 	if (argc != 0) {
 	    /* shell -c "command" */
 	    char *src, *dst;
-	    size_t cmnd_size = (size_t) (argv[argc - 1] - argv[0]) +
-		strlen(argv[argc - 1]) + 1;
+	    size_t size = 0;
 
-	    cmnd = dst = reallocarray(NULL, cmnd_size, 2);
-	    if (cmnd == NULL)
+	    for (av = argv; *av != NULL; av++)
+		size += strlen(*av) + 1;
+	    if (size == 0 || (cmnd = reallocarray(NULL, size, 2)) == NULL)
 		sudo_fatalx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
 	    if (!gc_add(GC_PTR, cmnd))
 		exit(1);
 
-	    for (av = argv; *av != NULL; av++) {
+	    for (dst = cmnd, av = argv; *av != NULL; av++) {
 		for (src = *av; *src != '\0'; src++) {
 		    /* quote potential meta characters */
 		    if (!isalnum((unsigned char)*src) && *src != '_' && *src != '-' && *src != '$')

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File sudo-CVE-2021-3156.patch of Package sudo (Revision ea169a758f4f594a82e6b447d8fcf12e)

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