[Qemu-devel] [PATCH] qga: fail early for invalid time

["Marc-André Lureau" <marcandre.lureau@redhat.com>]

It's possible to set system time with dates after 2070, however, it's
not possible to set the RTC. It has limitation to up to year
2070 (1970+100). In order to keep both clock in sync and before the
kernel complains on invalid values, bail out early.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 qga/commands-posix.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index befd00b..d8847be 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -154,6 +154,8 @@ void qmp_guest_set_time(bool has_time, int64_t time_ns, Error **errp)
 
     /* If user has passed a time, validate and set it. */
     if (has_time) {
+        GDate date = { 0, };
+
         /* year-2038 will overflow in case time_t is 32bit */
         if (time_ns / 1000000000 != (time_t)(time_ns / 1000000000)) {
             error_setg(errp, "Time %" PRId64 " is too large", time_ns);
@@ -162,6 +164,11 @@ void qmp_guest_set_time(bool has_time, int64_t time_ns, Error **errp)
 
         tv.tv_sec = time_ns / 1000000000;
         tv.tv_usec = (time_ns % 1000000000) / 1000;
+        g_date_set_time_t(&date, tv.tv_sec);
+        if (date.year < 1970 || date.year >= 2070) {
+            error_setg_errno(errp, errno, "Invalid time");
+            return;
+        }
 
         ret = settimeofday(&tv, NULL);
         if (ret < 0) {
-- 
2.4.3