File sudo-CVE-2021-3156.patch of Package sudo.32788
# 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 != '$')
