From 07caad7e0a9afb372e0608299fb3e832cc78495f Mon Sep 17 00:00:00 2001
From: DRC <information@libjpeg-turbo.org>
Date: Tue, 2 Jun 2020 14:15:37 -0500
Subject: [PATCH] rdppm.c: Fix buf overrun caused by bad binary PPM

This extends the fix in 1e81b0c3ea26f4ea8f56de05367469333de64a9f to
include binary PPM files with maximum values < 255, thus preventing a
malformed binary PPM input file with those specifications from
triggering an overrun of the rescale array and potentially crashing
cjpeg, TJBench, or any program that uses the tjLoadImage() function.

Fixes #433

Upstream-Status: Backport [https://github.com/libjpeg-turbo/libjpeg-turbo/commit/3de15e0c344d11d4b90f4a47136467053eb2d09a]
CVE: CVE-2020-13790
Signed-off-by: Chee Yang Lee <chee.yang.lee@intel.com>

---
 ChangeLog.md | 14 ++++++++++----
 rdppm.c      |  4 ++--
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index 4d1219e..af660ab 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -38,6 +38,12 @@ this issue did not likely pose a security risk.
 separate read-only data section rather than in the text section, to support
 execute-only memory layouts.
 
+3. Fixed an issue in the PPM reader that caused a buffer overrun in cjpeg,
+TJBench, or the `tjLoadImage()` function if one of the values in a binary
+PPM/PGM input file exceeded the maximum value defined in the file's header and
+that maximum value was less than 255.  libjpeg-turbo 1.5.0 already included a
+similar fix for binary PPM/PGM files with maximum values greater than 255.
+
 
 2.0.3
 =====
@@ -562,10 +568,10 @@ application was linked against.
 
 3. Fixed a couple of issues in the PPM reader that would cause buffer overruns
 in cjpeg if one of the values in a binary PPM/PGM input file exceeded the
-maximum value defined in the file's header.  libjpeg-turbo 1.4.2 already
-included a similar fix for ASCII PPM/PGM files.  Note that these issues were
-not security bugs, since they were confined to the cjpeg program and did not
-affect any of the libjpeg-turbo libraries.
+maximum value defined in the file's header and that maximum value was greater
+than 255.  libjpeg-turbo 1.4.2 already included a similar fix for ASCII PPM/PGM
+files.  Note that these issues were not security bugs, since they were confined
+to the cjpeg program and did not affect any of the libjpeg-turbo libraries.
 
 4. Fixed an issue whereby attempting to decompress a JPEG file with a corrupt
 header using the `tjDecompressToYUV2()` function would cause the function to
diff --git a/rdppm.c b/rdppm.c
index 87bc330..a8507b9 100644
--- a/rdppm.c
+++ b/rdppm.c
@@ -5,7 +5,7 @@
  * Copyright (C) 1991-1997, Thomas G. Lane.
  * Modified 2009 by Bill Allombert, Guido Vollbeding.
  * libjpeg-turbo Modifications:
- * Copyright (C) 2015-2017, D. R. Commander.
+ * Copyright (C) 2015-2017, 2020, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README.ijg
  * file.
  *
@@ -720,7 +720,7 @@ start_input_ppm(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
     /* On 16-bit-int machines we have to be careful of maxval = 65535 */
     source->rescale = (JSAMPLE *)
       (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
-                                  (size_t)(((long)maxval + 1L) *
+                                  (size_t)(((long)MAX(maxval, 255) + 1L) *
                                            sizeof(JSAMPLE)));
     half_maxval = maxval / 2;
     for (val = 0; val <= (long)maxval; val++) {