From b184e783702246e154294326d03d9abda669fcfa Mon Sep 17 00:00:00 2001 From: Shailesh Mistry Date: Wed, 3 May 2017 22:06:01 +0100 Subject: [PATCH] Bug 697703: Prevent integer overflow vulnerability. Add extra check for the offset being greater than the size of the image and hence reading off the end of the buffer. Thank you to Dai Ge for finding this issue and suggesting a patch. --- jbig2dec/jbig2_symbol_dict.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/jbig2dec/jbig2_symbol_dict.c b/jbig2dec/jbig2_symbol_dict.c index 4acaba9d0..36225cb1f 100644 --- a/jbig2_symbol_dict.c +++ b/jbig2_symbol_dict.c @@ -629,7 +629,7 @@ jbig2_decode_symbol_dict(Jbig2Ctx *ctx, byte *dst = image->data; /* SumatraPDF: prevent read access violation */ - if (size - jbig2_huffman_offset(hs) < image->height * stride) { + if ((size - jbig2_huffman_offset(hs) < image->height * stride) || (size < jbig2_huffman_offset(hs))) { jbig2_error(ctx, JBIG2_SEVERITY_FATAL, segment->number, "not enough data for decoding (%d/%d)", image->height * stride, size - jbig2_huffman_offset(hs)); jbig2_image_release(ctx, image); -- 2.13.1