[oe-commits] [openembedded-core] 26/66: libexif: fix CVE-2016-6328 and CVE-2018-20030
git at git.openembedded.org
git at git.openembedded.org
Tue May 21 23:32:49 UTC 2019
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rpurdie pushed a commit to branch thud
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commit fbb34412641afa0fa7327cf599b82564ca375217
Author: Ross Burton <ross.burton at intel.com>
AuthorDate: Wed Mar 27 13:40:38 2019 +0000
libexif: fix CVE-2016-6328 and CVE-2018-20030
Signed-off-by: Ross Burton <ross.burton at intel.com>
Signed-off-by: Richard Purdie <richard.purdie at linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster808 at gmail.com>
---
.../libexif/libexif/CVE-2016-6328.patch | 64 ++++++++++++
.../libexif/libexif/CVE-2018-20030.patch | 115 +++++++++++++++++++++
meta/recipes-support/libexif/libexif_0.6.21.bb | 4 +-
3 files changed, 182 insertions(+), 1 deletion(-)
diff --git a/meta/recipes-support/libexif/libexif/CVE-2016-6328.patch b/meta/recipes-support/libexif/libexif/CVE-2016-6328.patch
new file mode 100644
index 0000000..a6f3074
--- /dev/null
+++ b/meta/recipes-support/libexif/libexif/CVE-2016-6328.patch
@@ -0,0 +1,64 @@
+CVE: CVE-2016-6328
+Upstream-Status: Backport
+Signed-off-by: Ross Burton <ross.burton at intel.com>
+
+From 41bd04234b104312f54d25822f68738ba8d7133d Mon Sep 17 00:00:00 2001
+From: Marcus Meissner <marcus at jet.franken.de>
+Date: Tue, 25 Jul 2017 23:44:44 +0200
+Subject: [PATCH] fixes some (not all) buffer overreads during decoding pentax
+ makernote entries.
+
+This should fix:
+https://sourceforge.net/p/libexif/bugs/125/ CVE-2016-6328
+---
+ libexif/pentax/mnote-pentax-entry.c | 16 +++++++++++++---
+ 1 file changed, 13 insertions(+), 3 deletions(-)
+
+diff --git a/libexif/pentax/mnote-pentax-entry.c b/libexif/pentax/mnote-pentax-entry.c
+index d03d159..ea0429a 100644
+--- a/libexif/pentax/mnote-pentax-entry.c
++++ b/libexif/pentax/mnote-pentax-entry.c
+@@ -425,24 +425,34 @@ mnote_pentax_entry_get_value (MnotePentaxEntry *entry,
+ case EXIF_FORMAT_SHORT:
+ {
+ const unsigned char *data = entry->data;
+- size_t k, len = strlen(val);
++ size_t k, len = strlen(val), sizeleft;
++
++ sizeleft = entry->size;
+ for(k=0; k<entry->components; k++) {
++ if (sizeleft < 2)
++ break;
+ vs = exif_get_short (data, entry->order);
+ snprintf (val+len, maxlen-len, "%i ", vs);
+ len = strlen(val);
+ data += 2;
++ sizeleft -= 2;
+ }
+ }
+ break;
+ case EXIF_FORMAT_LONG:
+ {
+ const unsigned char *data = entry->data;
+- size_t k, len = strlen(val);
++ size_t k, len = strlen(val), sizeleft;
++
++ sizeleft = entry->size;
+ for(k=0; k<entry->components; k++) {
++ if (sizeleft < 4)
++ break;
+ vl = exif_get_long (data, entry->order);
+ snprintf (val+len, maxlen-len, "%li", (long int) vl);
+ len = strlen(val);
+ data += 4;
++ sizeleft -= 4;
+ }
+ }
+ break;
+@@ -455,5 +465,5 @@ mnote_pentax_entry_get_value (MnotePentaxEntry *entry,
+ break;
+ }
+
+- return (val);
++ return val;
+ }
diff --git a/meta/recipes-support/libexif/libexif/CVE-2018-20030.patch b/meta/recipes-support/libexif/libexif/CVE-2018-20030.patch
new file mode 100644
index 0000000..76233e6
--- /dev/null
+++ b/meta/recipes-support/libexif/libexif/CVE-2018-20030.patch
@@ -0,0 +1,115 @@
+CVE: CVE-2018-20030
+Upstream-Status: Backport
+Signed-off-by: Ross Burton <ross.burton at intel.com>
+
+From 6aa11df549114ebda520dde4cdaea2f9357b2c89 Mon Sep 17 00:00:00 2001
+From: Dan Fandrich <dan at coneharvesters.com>
+Date: Fri, 12 Oct 2018 16:01:45 +0200
+Subject: [PATCH] Improve deep recursion detection in
+ exif_data_load_data_content.
+
+The existing detection was still vulnerable to pathological cases
+causing DoS by wasting CPU. The new algorithm takes the number of tags
+into account to make it harder to abuse by cases using shallow recursion
+but with a very large number of tags. This improves on commit 5d28011c
+which wasn't sufficient to counter this kind of case.
+
+The limitation in the previous fix was discovered by Laurent Delosieres,
+Secunia Research at Flexera (Secunia Advisory SA84652) and is assigned
+the identifier CVE-2018-20030.
+
+diff --git a/libexif/exif-data.c b/libexif/exif-data.c
+index 67df4db..8d9897e 100644
+--- a/libexif/exif-data.c
++++ b/libexif/exif-data.c
+@@ -35,6 +35,7 @@
+ #include <libexif/olympus/exif-mnote-data-olympus.h>
+ #include <libexif/pentax/exif-mnote-data-pentax.h>
+
++#include <math.h>
+ #include <stdlib.h>
+ #include <stdio.h>
+ #include <string.h>
+@@ -344,6 +345,20 @@ if (data->ifd[(i)]->count) { \
+ break; \
+ }
+
++/*! Calculate the recursion cost added by one level of IFD loading.
++ *
++ * The work performed is related to the cost in the exponential relation
++ * work=1.1**cost
++ */
++static unsigned int
++level_cost(unsigned int n)
++{
++ static const double log_1_1 = 0.09531017980432493;
++
++ /* Adding 0.1 protects against the case where n==1 */
++ return ceil(log(n + 0.1)/log_1_1);
++}
++
+ /*! Load data for an IFD.
+ *
+ * \param[in,out] data #ExifData
+@@ -351,13 +366,13 @@ if (data->ifd[(i)]->count) { \
+ * \param[in] d pointer to buffer containing raw IFD data
+ * \param[in] ds size of raw data in buffer at \c d
+ * \param[in] offset offset into buffer at \c d at which IFD starts
+- * \param[in] recursion_depth number of times this function has been
+- * recursively called without returning
++ * \param[in] recursion_cost factor indicating how expensive this recursive
++ * call could be
+ */
+ static void
+ exif_data_load_data_content (ExifData *data, ExifIfd ifd,
+ const unsigned char *d,
+- unsigned int ds, unsigned int offset, unsigned int recursion_depth)
++ unsigned int ds, unsigned int offset, unsigned int recursion_cost)
+ {
+ ExifLong o, thumbnail_offset = 0, thumbnail_length = 0;
+ ExifShort n;
+@@ -372,9 +387,20 @@ exif_data_load_data_content (ExifData *data, ExifIfd ifd,
+ if ((((int)ifd) < 0) || ( ((int)ifd) >= EXIF_IFD_COUNT))
+ return;
+
+- if (recursion_depth > 30) {
++ if (recursion_cost > 170) {
++ /*
++ * recursion_cost is a logarithmic-scale indicator of how expensive this
++ * recursive call might end up being. It is an indicator of the depth of
++ * recursion as well as the potential for worst-case future recursive
++ * calls. Since it's difficult to tell ahead of time how often recursion
++ * will occur, this assumes the worst by assuming every tag could end up
++ * causing recursion.
++ * The value of 170 was chosen to limit typical EXIF structures to a
++ * recursive depth of about 6, but pathological ones (those with very
++ * many tags) to only 2.
++ */
+ exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA, "ExifData",
+- "Deep recursion detected!");
++ "Deep/expensive recursion detected!");
+ return;
+ }
+
+@@ -416,15 +442,18 @@ exif_data_load_data_content (ExifData *data, ExifIfd ifd,
+ switch (tag) {
+ case EXIF_TAG_EXIF_IFD_POINTER:
+ CHECK_REC (EXIF_IFD_EXIF);
+- exif_data_load_data_content (data, EXIF_IFD_EXIF, d, ds, o, recursion_depth + 1);
++ exif_data_load_data_content (data, EXIF_IFD_EXIF, d, ds, o,
++ recursion_cost + level_cost(n));
+ break;
+ case EXIF_TAG_GPS_INFO_IFD_POINTER:
+ CHECK_REC (EXIF_IFD_GPS);
+- exif_data_load_data_content (data, EXIF_IFD_GPS, d, ds, o, recursion_depth + 1);
++ exif_data_load_data_content (data, EXIF_IFD_GPS, d, ds, o,
++ recursion_cost + level_cost(n));
+ break;
+ case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
+ CHECK_REC (EXIF_IFD_INTEROPERABILITY);
+- exif_data_load_data_content (data, EXIF_IFD_INTEROPERABILITY, d, ds, o, recursion_depth + 1);
++ exif_data_load_data_content (data, EXIF_IFD_INTEROPERABILITY, d, ds, o,
++ recursion_cost + level_cost(n));
+ break;
+ case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
+ thumbnail_offset = o;
diff --git a/meta/recipes-support/libexif/libexif_0.6.21.bb b/meta/recipes-support/libexif/libexif_0.6.21.bb
index b550a11..4cb7e6b 100644
--- a/meta/recipes-support/libexif/libexif_0.6.21.bb
+++ b/meta/recipes-support/libexif/libexif_0.6.21.bb
@@ -5,7 +5,9 @@ LICENSE = "LGPLv2.1"
LIC_FILES_CHKSUM = "file://COPYING;md5=243b725d71bb5df4a1e5920b344b86ad"
SRC_URI = "${SOURCEFORGE_MIRROR}/libexif/libexif-${PV}.tar.bz2 \
- file://CVE-2017-7544.patch"
+ file://CVE-2017-7544.patch \
+ file://CVE-2016-6328.patch \
+ file://CVE-2018-20030.patch"
SRC_URI[md5sum] = "27339b89850f28c8f1c237f233e05b27"
SRC_URI[sha256sum] = "16cdaeb62eb3e6dfab2435f7d7bccd2f37438d21c5218ec4e58efa9157d4d41a"
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