ffmpeg: fix CVE-2021-33815

avcodec/exr: More strictly check dc_count

Fixes: out of array access
Fixes: exr/deneme

Found-by: Burak Çarıkçı <burakcarikci@crypttech.com>
(From OE-Core rev: e03fda4df5d2865d5ac516f45aa120e2caf7de47)

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

CVE: CVE-2021-33815
Upstream-Status: Backport [26d3c81bc5ef2f8c3f09d45eaeacfb4b1139a777]

Signed-off-by: Tony Tascioglu <tony.tascioglu@windriver.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 45 insertions, 0 deletions

diff --git a/meta/recipes-multimedia/ffmpeg/ffmpeg/fix-CVE-2021-33815.patch b/meta/recipes-multimedia/ffmpeg/ffmpeg/fix-CVE-2021-33815.patch
new file mode 100644
index 0000000000..51edb76389
--- /dev/null
+++ b/meta/recipes-multimedia/ffmpeg/ffmpeg/fix-CVE-2021-33815.patch
@@ -0,0 +1,44 @@
+From 26d3c81bc5ef2f8c3f09d45eaeacfb4b1139a777 Mon Sep 17 00:00:00 2001
+From: Michael Niedermayer <michael@niedermayer.cc>
+Date: Tue, 25 May 2021 19:29:18 +0200
+Subject: [PATCH] avcodec/exr: More strictly check dc_count
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Fixes: out of array access
+Fixes: exr/deneme
+
+Found-by: Burak Çarıkçı <burakcarikci@crypttech.com>
+Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
+
+
+CVE: CVE-2021-33815
+Upstream-Status: Backport [26d3c81bc5ef2f8c3f09d45eaeacfb4b1139a777]
+
+Signed-off-by: Tony Tascioglu <tony.tascioglu@windriver.com>
+---
+ libavcodec/exr.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/libavcodec/exr.c b/libavcodec/exr.c
+index 9377a89169..4648ed7d62 100644
+--- a/libavcodec/exr.c
++++ b/libavcodec/exr.c
+@@ -1059,11 +1059,11 @@ static int dwa_uncompress(EXRContext *s, const uint8_t *src, int compressed_size
+         bytestream2_skip(&gb, ac_size);
+     }
+ 
+-    if (dc_size > 0) {
++    {
+         unsigned long dest_len = dc_count * 2LL;
+         GetByteContext agb = gb;
+ 
+-        if (dc_count > (6LL * td->xsize * td->ysize + 63) / 64)
++        if (dc_count != dc_w * dc_h * 3)
+             return AVERROR_INVALIDDATA;
+ 
+         av_fast_padded_malloc(&td->dc_data, &td->dc_size, FFALIGN(dest_len, 64) * 2);
+-- 
+2.32.0
+
diff --git a/meta/recipes-multimedia/ffmpeg/ffmpeg_4.4.bb b/meta/recipes-multimedia/ffmpeg/ffmpeg_4.4.bb
index 70b1513048..02af257d0f 100644
--- a/meta/recipes-multimedia/ffmpeg/ffmpeg_4.4.bb
+++ b/meta/recipes-multimedia/ffmpeg/ffmpeg_4.4.bb
@@ -30,6 +30,7 @@ SRC_URI = "https://www.ffmpeg.org/releases/${BP}.tar.xz \
            file://fix-CVE-2020-22015.patch \
            file://fix-CVE-2020-22021.patch \
            file://fix-CVE-2020-22033-CVE-2020-22019.patch \
+           file://fix-CVE-2021-33815.patch \
            "
 SRC_URI[sha256sum] = "06b10a183ce5371f915c6bb15b7b1fffbe046e8275099c96affc29e17645d909"