better validation on delta base object offsets
In one case, it was possible to have a bad offset equal to 0 effectively
pointing a delta onto itself and crashing git after too many recursions.
In the other cases, a negative offset could result due to off_t being
signed. Catch those.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin-unpack-objects.c b/builtin-unpack-objects.c
index 9f4bdd3..47ed610 100644
--- a/builtin-unpack-objects.c
+++ b/builtin-unpack-objects.c
@@ -370,6 +370,8 @@
base_offset = (base_offset << 7) + (c & 127);
}
base_offset = obj_list[nr].offset - base_offset;
+ if (base_offset <= 0 || base_offset >= obj_list[nr].offset)
+ die("offset value out of bound for delta base object");
delta_data = get_data(delta_size);
if (dry_run || !delta_data) {
