diff --git a/tools/pal2rgb.c b/tools/pal2rgb.c
index 0423598..01fcf94 100644
--- a/tools/pal2rgb.c
+++ b/tools/pal2rgb.c
@@ -182,8 +182,21 @@ main(int argc, char* argv[])
{ unsigned char *ibuf, *obuf;
register unsigned char* pp;
register uint32 x;
- ibuf = (unsigned char*)_TIFFmalloc(TIFFScanlineSize(in));
- obuf = (unsigned char*)_TIFFmalloc(TIFFScanlineSize(out));
+ tmsize_t tss_in = TIFFScanlineSize(in);
+ tmsize_t tss_out = TIFFScanlineSize(out);
+ if (tss_out / tss_in < 3) {
+ /*
+ * BUG 2750: The following code does not know about chroma
+ * subsampling of JPEG data. It assumes that the output buffer is 3x
+ * the length of the input buffer due to exploding the palette into
+ * RGB tuples. If this assumption is incorrect, it could lead to a
+ * buffer overflow. Go ahead and fail now to prevent that.
+ */
+ fprintf(stderr, "Could not determine correct image size for output. Exiting.\n");
+ return -1;
+ }
+ ibuf = (unsigned char*)_TIFFmalloc(tss_in);
+ obuf = (unsigned char*)_TIFFmalloc(tss_out);
switch (config) {
case PLANARCONFIG_CONTIG:
for (row = 0; row < imagelength; row++) {