From 7d45c53cd27d9c278d36b2c188ebe26077e11d11 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Higor=20Eur=C3=ADpedes?= Date: Tue, 17 Dec 2013 23:28:16 -0300 Subject: [PATCH] fixed miscalculation for small header chunks --- ipsbehead.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/ipsbehead.c b/ipsbehead.c index 0e8c717..b3d43c8 100644 --- a/ipsbehead.c +++ b/ipsbehead.c @@ -86,16 +86,22 @@ static int read_record(FILE* fp, struct ips_record *rec) { } static void behead(struct ips_record *in, struct ips_record *out) { + int skip = 0; /* fix offsets & truncate record data */ out->off = in->off; out->len = in->len; out->is_rle = in->is_rle; if (in->off < 0x200) { - out->off = 0x200 - in->off; - out->len -= out->off; - out->off = 0; + out->len -= in->off; + + /* skip node if ends before 0x200 or overflow happened */ + if (out->off + out->len < 0x200 || out->len > in->len) + out->len = 0; + + skip = in->len - out->len; + } else { out->off = in->off - 0x200; } @@ -104,7 +110,7 @@ static void behead(struct ips_record *in, struct ips_record *out) { if (out->is_rle) out->data[0] = in->data[0]; else - memcpy(out->data, in->data, out->len); + memcpy(out->data, in->data + skip, out->len - skip); } } @@ -145,8 +151,8 @@ int main (int argc, char* argv[]) { printf("%5i | %06x - %06x | %06x - %06x | %s\n", chunkno, - in.off, in.off + in.len-1, - out.off, out.off + out.len-1, + in.off, (in.len ? (in.off + in.len-1) : in.off), + out.off, (out.len ? (out.off + out.len-1) : out.off), (in.is_rle) ? "Y" : "N"); chunkno++; }