malloc the deflate buffer in pngo

The stack is a baby.

1 files changed, 5 insertions, 1 deletions

diff --git a/bin/pngo.c b/bin/pngo.c
index 49c734da..d5f7b652 100644
--- a/bin/pngo.c
+++ b/bin/pngo.c
@@ -334,7 +334,9 @@ static void writeData(void) {
 	if (verbose) fprintf(stderr, "%s: data size %zu\n", path, dataSize());
 
 	uLong size = compressBound(dataSize());
-	uint8_t deflate[size];
+	uint8_t *deflate = malloc(size);
+	if (!deflate) err(EX_OSERR, "malloc");
+
 	int error = compress2(deflate, &size, data, dataSize(), Z_BEST_COMPRESSION);
 	if (error != Z_OK) errx(EX_SOFTWARE, "%s: compress2: %d", path, error);
 
@@ -343,6 +345,8 @@ static void writeData(void) {
 	writeExpect(deflate, size);
 	writeCrc();
 
+	free(deflate);
+
 	if (verbose) fprintf(stderr, "%s: deflate size %lu\n", path, size);
 }