graphics/libexif: Fix security vulnerabilities

 - Fix CVE-2019-9278

  In libexif, there is a possible out of bounds write due to an integer
  overflow. This could lead to remote escalation of privilege in the media
  content provider with no additional execution privileges needed. User
  interaction is needed for exploitation.

 - Fix a buffer read overflow in exif_entry_get_value

 - Fix a buffer overread in exif_mnote_data_olympus_load

PR:		244060
Reported by:	tj@mrsk.me (email)
Approved by:	former maintainer
MFH:		2020Q1
Security:	00f30cba-4d23-11ea-86ba-641c67a117d8

3 files changed, 145 insertions, 0 deletions

diff --git a/graphics/libexif/files/patch-CVE-2019-9278 b/graphics/libexif/files/patch-CVE-2019-9278
new file mode 100644
index 000000000000..ac5e3f80b7d9
--- /dev/null
+++ b/graphics/libexif/files/patch-CVE-2019-9278
@@ -0,0 +1,86 @@
+https://github.com/libexif/libexif/commit/75aa73267fdb1e0ebfbc00369e7312bac43d0566.patch
+From 75aa73267fdb1e0ebfbc00369e7312bac43d0566 Mon Sep 17 00:00:00 2001
+From: Marcus Meissner <meissner@suse.de>
+Date: Sat, 18 Jan 2020 09:29:42 +0100
+Subject: [PATCH] fix CVE-2019-9278
+
+avoid the use of unsafe integer overflow checking constructs (unsigned integer operations cannot overflow, so "u1 + u2 > u1" can be optimized away)
+
+check for the actual sizes, which should also handle the overflows
+document other places google patched, but do not seem relevant due to other restrictions
+
+fixes https://github.com/libexif/libexif/issues/26
+---
+ libexif/exif-data.c | 28 ++++++++++++++++++----------
+ 1 file changed, 18 insertions(+), 10 deletions(-)
+
+diff --git libexif/exif-data.c libexif/exif-data.c
+index a6f9c94..6332cd1 100644
+--- libexif/exif-data.c
++++ libexif/exif-data.c
+@@ -192,9 +192,15 @@ exif_data_load_data_entry (ExifData *data, ExifEntry *entry,
+ 		doff = offset + 8;
+ 
+ 	/* Sanity checks */
+-	if ((doff + s < doff) || (doff + s < s) || (doff + s > size)) {
++	if (doff >= size) {
+ 		exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
+-				  "Tag data past end of buffer (%u > %u)", doff+s, size);	
++				  "Tag starts past end of buffer (%u > %u)", doff, size);
++		return 0;
++	}
++
++	if (s > size - doff) {
++		exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
++				  "Tag data goes past end of buffer (%u > %u)", doff+s, size);
+ 		return 0;
+ 	}
+ 
+@@ -315,13 +321,14 @@ exif_data_load_data_thumbnail (ExifData *data, const unsigned char *d,
+ 			       unsigned int ds, ExifLong o, ExifLong s)
+ {
+ 	/* Sanity checks */
+-	if ((o + s < o) || (o + s < s) || (o + s > ds) || (o > ds)) {
+-		exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
+-			  "Bogus thumbnail offset (%u) or size (%u).",
+-			  o, s);
++	if (o >= ds) {
++		exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData", "Bogus thumbnail offset (%u).", o);
++		return;
++	}
++	if (s > ds - o) {
++		exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData", "Bogus thumbnail size (%u), max would be %u.", s, ds-o);
+ 		return;
+ 	}
+-
+ 	if (data->data) 
+ 		exif_mem_free (data->priv->mem, data->data);
+ 	if (!(data->data = exif_data_alloc (data, s))) {
+@@ -947,7 +954,7 @@ exif_data_load_data (ExifData *data, const unsigned char *d_orig,
+ 	exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData", 
+ 		  "IFD 0 at %i.", (int) offset);
+ 
+-	/* Sanity check the offset, being careful about overflow */
++	/* ds is restricted to 16 bit above, so offset is restricted too, and offset+8 should not overflow. */
+ 	if (offset > ds || offset + 6 + 2 > ds)
+ 		return;
+ 
+@@ -956,6 +963,7 @@ exif_data_load_data (ExifData *data, const unsigned char *d_orig,
+ 
+ 	/* IFD 1 offset */
+ 	n = exif_get_short (d + 6 + offset, data->priv->order);
++	/* offset < 2<<16, n is 16 bit at most, so this op will not overflow */
+ 	if (offset + 6 + 2 + 12 * n + 4 > ds)
+ 		return;
+ 
+@@ -964,8 +972,8 @@ exif_data_load_data (ExifData *data, const unsigned char *d_orig,
+ 		exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
+ 			  "IFD 1 at %i.", (int) offset);
+ 
+-		/* Sanity check. */
+-		if (offset > ds || offset + 6 > ds) {
++		/* Sanity check. ds is ensured to be above 6 above, offset is 16bit */
++		if (offset > ds - 6) {
+ 			exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
+ 				  "ExifData", "Bogus offset of IFD1.");
+ 		} else {
diff --git a/graphics/libexif/files/patch-chromium-7344-and-14543 b/graphics/libexif/files/patch-chromium-7344-and-14543
new file mode 100644
index 000000000000..4196d6ac9719
--- /dev/null
+++ b/graphics/libexif/files/patch-chromium-7344-and-14543
@@ -0,0 +1,35 @@
+https://github.com/libexif/libexif/commit/f9bb9f263fb00f0603ecbefa8957cad24168cbff.patch
+From f9bb9f263fb00f0603ecbefa8957cad24168cbff Mon Sep 17 00:00:00 2001
+From: Dan Fandrich <dan@coneharvesters.com>
+Date: Wed, 4 Jul 2018 11:06:09 +0200
+Subject: [PATCH] Fix a buffer read overflow in exif_entry_get_value
+
+While parsing EXIF_TAG_FOCAL_LENGTH it was possible to read 8 bytes past
+the end of a heap buffer. This was detected by the OSS Fuzz project.
+Patch from Google.
+
+Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=7344 and
+https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=14543
+---
+ libexif/exif-entry.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git libexif/exif-entry.c libexif/exif-entry.c
+index 61260d3..a224ac2 100644
+--- libexif/exif-entry.c
++++ libexif/exif-entry.c
+@@ -1040,12 +1040,12 @@ exif_entry_get_value (ExifEntry *e, char *val, unsigned int maxlen)
+ 		d = 0.;
+ 		entry = exif_content_get_entry (
+ 			e->parent->parent->ifd[EXIF_IFD_0], EXIF_TAG_MAKE);
+-		if (entry && entry->data &&
++		if (entry && entry->data && entry->size >= 7 &&
+ 		    !strncmp ((char *)entry->data, "Minolta", 7)) {
+ 			entry = exif_content_get_entry (
+ 					e->parent->parent->ifd[EXIF_IFD_0],
+ 					EXIF_TAG_MODEL);
+-			if (entry && entry->data) {
++			if (entry && entry->data && entry->size >= 8) {
+ 				if (!strncmp ((char *)entry->data, "DiMAGE 7", 8))
+ 					d = 3.9;
+ 				else if (!strncmp ((char *)entry->data, "DiMAGE 5", 8))
diff --git a/graphics/libexif/files/patch-chromium-8884 b/graphics/libexif/files/patch-chromium-8884
new file mode 100644
index 000000000000..55673b941971
--- /dev/null
+++ b/graphics/libexif/files/patch-chromium-8884
@@ -0,0 +1,24 @@
+https://github.com/libexif/libexif/commit/a0c04d9cb6ab0c41a6458def9f892754e84160a0.patch
+From a0c04d9cb6ab0c41a6458def9f892754e84160a0 Mon Sep 17 00:00:00 2001
+From: Marcus Meissner <marcus@jet.franken.de>
+Date: Sat, 15 Jun 2019 18:40:48 +0200
+Subject: [PATCH] fixed a buffer overread (OSS-Fuzz)
+ https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=8884
+
+---
+ libexif/olympus/exif-mnote-data-olympus.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git libexif/olympus/exif-mnote-data-olympus.c libexif/olympus/exif-mnote-data-olympus.c
+index dac7f5b..669e4ec 100644
+--- libexif/olympus/exif-mnote-data-olympus.c
++++ libexif/olympus/exif-mnote-data-olympus.c
+@@ -344,7 +344,7 @@ exif_mnote_data_olympus_load (ExifMnoteData *en,
+ 
+ 	case nikonV2:
+ 		o2 += 6;
+-		if (o2 >= buf_size) return;
++		if (o2 + 8 >= buf_size) return;
+ 		exif_log (en->log, EXIF_LOG_CODE_DEBUG, "ExifMnoteDataOlympus",
+ 			"Parsing Nikon maker note v2 (0x%02x, %02x, %02x, "
+ 			"%02x, %02x, %02x, %02x, %02x)...",