libansilove

commit 73b4cc342a57462fbc05fdc12437fc9fecb6ec3d
parent 5899f54a0467ba5d31f63fc56214a06ba6d36d95
Author: Frederic Cambus <fred@statdns.com>
Date:   Tue, 30 Apr 2019 17:24:46 +0200

Perform format validation checks before allocating memory, avoids leaking memory in case we error out.

Diffstat:
M
src/loaders/xbin.c
 | 
10
+++++-----

1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/src/loaders/xbin.c b/src/loaders/xbin.c
@@ -93,6 +93,11 @@ ansilove_xbin(struct ansilove_ctx *ctx, struct ansilove_options *options)
 		uint32_t numchars = (xbin_flags & 0x10 ? 512 : 256);
 		size_t fontsz = xbin_fontsize * numchars;
 
+		if (offset + fontsz > ctx->length) {
+			ctx->error = ANSILOVE_FORMAT_ERROR;
+			return -1;
+		}
+
 		/* allocate memory to contain the XBin font */
 		font_data_xbin = (uint8_t *)malloc(fontsz);
 		if (font_data_xbin == NULL) {
@@ -100,11 +105,6 @@ ansilove_xbin(struct ansilove_ctx *ctx, struct ansilove_options *options)
 			return -1;
 		}
 
-		if (offset + fontsz > ctx->length) {
-			ctx->error = ANSILOVE_FORMAT_ERROR;
-			return -1;
-		}
-
 		memcpy(font_data_xbin, ctx->buffer+offset, fontsz);
 
 		font_data = font_data_xbin;