scc

commit 94f23734015424515144b54f0a9f9d6c9d2f34c2
parent b843da74b79d585a30bd2b3f13e7c63d105baf94
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Mon, 16 May 2022 11:43:29 +0200

libc: Correct time zone copy in strftime()

Time zone are longer than 3 characters some times, and the
code was not checking the pending size in the buffer and
it could drive to buffer overflow problems.

Diffstat:
M
src/libc/time/strftime.c
 | 
9
+++++++--

1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/src/libc/time/strftime.c b/src/libc/time/strftime.c
@@ -293,8 +293,13 @@ strftime(char *restrict s, size_t maxsize,
 			inc = timezone(s, n, timeptr);
 			break;
 		case 'Z':
-			memcpy(s, timeptr->tm_zone, 3);
-			inc = 3;
+			inc = strlen(timeptr->tm_zone);
+			if (inc > n) {
+				*s = '?';
+				inc = 1;
+			} else {
+				memcpy(s, timeptr->tm_zone, inc);
+			}
 			break;
 		case '\0':
 			inc = 0;