win: Fix an out-of-bounds array access

We should not attempt to make a map of more LDLINUX.SYS
sectors than we have.  Simply multiplying a cluster count
times the number of sectors per cluster does not account
for unused sectors in the last used cluster.

Signed-off-by: Shao Miller <shao.miller@yrdsb.edu.on.ca>
Signed-off-by: Paulo Alcantara <pcacjr@gmail.com>

diff --git a/win/syslinux.c b/win/syslinux.c
index 13f25b6..26e5a27 100644 (file)
--- a/win/syslinux.c
+++ b/win/syslinux.c
@@ -409,7 +409,7 @@ int main(int argc, char *argv[])
            len.QuadPart = ((extent.NextVcn.QuadPart -
                             extent.FirstVcn.QuadPart) *
                            vol_info.SectorsPerCluster);
-           while (len.QuadPart--) {
+           while (len.QuadPart-- && nsectors < ldlinux_sectors) {
                *secp++ = lba.QuadPart++;
                nsectors++;
            }