commit 41873b17dbf689280a2f59f9e7187205a5b358f2
from: Omar Polo <op@omarpolo.com>
date: Wed Jun 05 07:40:28 2024 UTC

adjust some SIZE_MAX checks; ok millert@

commit - 58578a1a5cba826572864b8a62787325b5120b1e
commit + 41873b17dbf689280a2f59f9e7187205a5b358f2
blob - 2bb13ec800c4d056689ef15d9179ab3d8151a359
blob + 84302f45b8db014cc23483d23a273c03f7fa077c
--- lib/pack.c
+++ lib/pack.c
@@ -940,7 +940,7 @@ parse_negative_offset(int64_t *offset, size_t *len, st
 		if (pack->map) {
 			size_t mapoff;
 
-			if (delta_offset + *len > SIZE_MAX) {
+			if (delta_offset > SIZE_MAX - *len) {
 				return got_error_fmt(GOT_ERR_PACK_OFFSET,
 				    "mapoff %lld would overflow size_t",
 				    (long long)delta_offset + *len);
@@ -1098,7 +1098,7 @@ got_pack_parse_ref_delta(struct got_object_id *id,
 	if (pack->map) {
 		size_t mapoff;
 
-		if (delta_offset + tslen > SIZE_MAX) {
+		if (delta_offset > SIZE_MAX - tslen) {
 			return got_error_fmt(GOT_ERR_PACK_OFFSET,
 			    "mapoff %lld would overflow size_t",
 			    (long long)delta_offset + tslen);