edid-decode: check for non-0 filler bytes in LS Ext

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

1 files changed, 4 insertions, 0 deletions

diff --git a/parse-ls-ext-block.cpp b/parse-ls-ext-block.cpp
index 117abba..1776715 100644
--- a/parse-ls-ext-block.cpp
+++ b/parse-ls-ext-block.cpp
@@ -61,4 +61,8 @@ void edid_state::parse_ls_ext_block(const unsigned char *x)
 		parse_string_table(x + 1);
 		x += x[0];
 	}
+	if (!memchk(x, orig + 127 - x)) {
+		data_block.clear();
+		fail("Non-zero values in unused space\n");
+	}
 }