Fix CVE-2020-0181, CVE-2020-0198, and CVE-2020-0452

CVE-2020-0181-CVE-2020-0198.patch

@@ -0,0 +1,58 @@
+From ce03ad7ef4e8aeefce79192bf5b6f69fae396f0c Mon Sep 17 00:00:00 2001
+From: Marcus Meissner <marcus@jet.franken.de>
+Date: Mon, 8 Jun 2020 17:27:06 +0200
+Subject: [PATCH] fixed another unsigned integer overflow
+
+first fixed by google in android fork,
+https://android.googlesource.com/platform/external/libexif/+/1e187b62682ffab5003c702657d6d725b4278f16%5E%21/#F0
+
+(use a more generic overflow check method, also check second overflow instance.)
+
+https://security-tracker.debian.org/tracker/CVE-2020-0198
+---
+ libexif/exif-data.c | 10 ++++++----
+ 1 file changed, 6 insertions(+), 4 deletions(-)
+
+diff --git a/libexif/exif-data.c b/libexif/exif-data.c
+index 8b280d3..b495726 100644
+--- a/libexif/exif-data.c
++++ b/libexif/exif-data.c
+@@ -47,6 +47,8 @@
+ #undef JPEG_MARKER_APP1
+ #define JPEG_MARKER_APP1 0xe1
+ 
++#define CHECKOVERFLOW(offset,datasize,structsize) (( offset >= datasize) || (structsize > datasize) || (offset > datasize - structsize ))
++
+ static const unsigned char ExifHeader[] = {0x45, 0x78, 0x69, 0x66, 0x00, 0x00};
+ 
+ struct _ExifDataPrivate
+@@ -327,7 +329,7 @@ exif_data_load_data_thumbnail (ExifData *data, const unsigned char *d,
+ 		exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData", "Bogus thumbnail offset (%u).", o);
+ 		return;
+ 	}
+-	if (s > ds - o) {
++	if (CHECKOVERFLOW(o,ds,s)) {
+ 		exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData", "Bogus thumbnail size (%u), max would be %u.", s, ds-o);
+ 		return;
+ 	}
+@@ -420,9 +422,9 @@ exif_data_load_data_content (ExifData *data, ExifIfd ifd,
+ 	}
+ 
+ 	/* Read the number of entries */
+-	if ((offset + 2 < offset) || (offset + 2 < 2) || (offset + 2 > ds)) {
++	if (CHECKOVERFLOW(offset, ds, 2)) {
+ 		exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA, "ExifData",
+-			  "Tag data past end of buffer (%u > %u)", offset+2, ds);
++			  "Tag data past end of buffer (%u+2 > %u)", offset, ds);
+ 		return;
+ 	}
+ 	n = exif_get_short (d + offset, data->priv->order);
+@@ -431,7 +433,7 @@ exif_data_load_data_content (ExifData *data, ExifIfd ifd,
+ 	offset += 2;
+ 
+ 	/* Check if we have enough data. */
+-	if (offset + 12 * n > ds) {
++	if (CHECKOVERFLOW(offset, ds, 12*n)) {
+ 		n = (ds - offset) / 12;
+ 		exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
+ 				  "Short data; only loading %hu entries...", n);

CVE-2020-0452.patch

@@ -0,0 +1,32 @@
+From 9266d14b5ca4e29b970fa03272318e5f99386e06 Mon Sep 17 00:00:00 2001
+From: Marcus Meissner <marcus@jet.franken.de>
+Date: Thu, 5 Nov 2020 09:50:08 +0100
+Subject: [PATCH] fixed a incorrect overflow check that could be optimized
+ away.
+
+inspired by:
+https://android.googlesource.com/platform/external/libexif/+/8e7345f3bc0bad06ac369d6cbc1124c8ceaf7d4b
+
+https://source.android.com/security/bulletin/2020-11-01
+
+CVE-2020-0452
+---
+ NEWS                 | 3 ++-
+ libexif/exif-entry.c | 4 ++--
+ 2 files changed, 4 insertions(+), 3 deletions(-)
+
+diff --git a/libexif/exif-entry.c b/libexif/exif-entry.c
+index 3fc0ff9..4b866ce 100644
+--- a/libexif/exif-entry.c
++++ b/libexif/exif-entry.c
+@@ -1371,8 +1371,8 @@ exif_entry_get_value (ExifEntry *e, char *val, unsigned int maxlen)
+ 	{
+ 		unsigned char *utf16;
+ 
+-		/* Sanity check the size to prevent overflow */
+-		if (e->size+sizeof(uint16_t)+1 < e->size) break;
++		/* Sanity check the size to prevent overflow. Note EXIF files are 64kb at most. */
++		if (e->size >= 65536 - sizeof(uint16_t)*2) break;
+ 
+ 		/* The tag may not be U+0000-terminated , so make a local
+ 		   U+0000-terminated copy before converting it */

libexif.spec

@@ -7,6 +7,11 @@ URL:		https://libexif.github.io/
 %global tarball_version %(echo %{version} | sed -e 's|\\.|_|g')
 Source0:	https://github.com/libexif/libexif/archive/libexif-%{tarball_version}-release.tar.gz
 
+# https://github.com/libexif/libexif/commit/ce03ad7ef4e8aeefce79192bf5b6f69fae396f0c
+Patch0:         CVE-2020-0181-CVE-2020-0198.patch
+# https://github.com/libexif/libexif/commit/9266d14b5ca4e29b970fa03272318e5f99386e06
+Patch1:         CVE-2020-0452.patch
+
 BuildRequires:	autoconf
 BuildRequires:	automake
 BuildRequires:	doxygen
@@ -77,6 +82,9 @@ make check
 
 
 %changelog
+* Mon Nov 09 2020 Michael Catanzaro <mcatanzaro@redhat.com> - 0.6.22-3
+- Fix CVE-2020-0181, CVE-2020-0198, and CVE-2020-0452
+
 * Tue Jul 28 2020 Fedora Release Engineering <releng@fedoraproject.org> - 0.6.22-2
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_33_Mass_Rebuild