From ea9e2896ce894e660cfe5c9bef6f17c3e9ad56f0 Mon Sep 17 00:00:00 2001 From: Philip Withnall Date: Tue, 18 Feb 2025 16:44:58 +0000 Subject: gdatetime: Fix integer overflow when parsing very long ISO8601 inputs This will only happen with invalid (or maliciously invalid) potential ISO8601 strings, but `g_date_time_new_from_iso8601()` needs to be robust against that. Prevent `length` overflowing by correctly defining it as a `size_t`. Similarly for `date_length`, but additionally track its validity in a boolean rather than as its sign. Spotted by chamalsl as #YWH-PGM9867-43. Signed-off-by: Philip Withnall --- glib/gdatetime.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/glib/gdatetime.c b/glib/gdatetime.c index a9c472e55..92a313418 100644 --- a/glib/gdatetime.c +++ b/glib/gdatetime.c @@ -1497,7 +1497,8 @@ parse_iso8601_time (const gchar *text, gsize length, GDateTime * g_date_time_new_from_iso8601 (const gchar *text, GTimeZone *default_tz) { - gint length, date_length = -1; + size_t length, date_length = 0; + gboolean date_length_set = FALSE; gint hour = 0, minute = 0; gdouble seconds = 0.0; GTimeZone *tz = NULL; @@ -1508,11 +1509,14 @@ g_date_time_new_from_iso8601 (const gchar *text, GTimeZone *default_tz) /* Count length of string and find date / time separator ('T', 't', or ' ') */ for (length = 0; text[length] != '\0'; length++) { - if (date_length < 0 && (text[length] == 'T' || text[length] == 't' || text[length] == ' ')) - date_length = length; + if (!date_length_set && (text[length] == 'T' || text[length] == 't' || text[length] == ' ')) + { + date_length = length; + date_length_set = TRUE; + } } - if (date_length < 0) + if (!date_length_set) return NULL; if (!parse_iso8601_time (text + date_length + 1, length - (date_length + 1), -- 2.30.2