brotli: add patch to fix CVE-2020-8927

Port patch to fix CVE-2020-8927 for brotli from Debian Buster

CVE: CVE-2020-8927

Signed-off-by: Jan Kraemer <jan@spectrejan.de>
[Fixup to apply with URL changes]
Signed-off-by: Armin Kuster <akuster808@gmail.com>

2 files changed, 47 insertions, 1 deletions

diff --git a/meta-oe/recipes-extended/brotli/brotli/0001-brotli-fix-CVE-2020-8927.patch b/meta-oe/recipes-extended/brotli/brotli/0001-brotli-fix-CVE-2020-8927.patch
new file mode 100644
index 000000000..c21794d14
--- /dev/null
+++ b/meta-oe/recipes-extended/brotli/brotli/0001-brotli-fix-CVE-2020-8927.patch
@@ -0,0 +1,44 @@
+From 95ab3786ce0f16e08e41f7bf216969a37dc86cad Mon Sep 17 00:00:00 2001
+From: Jan Kraemer <jan@spectrejan.de>
+Date: Thu, 7 Oct 2021 12:48:04 +0200
+Subject: [PATCH] brotli: fix CVE-2020-8927
+
+[No upstream tracking] --
+
+This fixes a potential overflow when input chunk is >2GiB in
+BrotliGetAvailableBits by capping the returned value to 2^30
+
+Fixed in brotli version 1.0.8
+https://github.com/google/brotli as of commit id
+223d80cfbec8fd346e32906c732c8ede21f0cea6
+
+Patch taken from Debian Buster: 1.0.7-2+deb10u1
+http://deb.debian.org/debian/pool/main/b/brotli/brotli_1.0.7-2+deb10u1.dsc
+https://security-tracker.debian.org/tracker/CVE-2020-8927
+
+
+Upstream-Status: Backported
+CVE: CVE-2020-8927
+
+Signed-off-by: Jan Kraemer <jan@spectrejan.de>
+---
+ c/dec/bit_reader.h | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+diff --git a/c/dec/bit_reader.h b/c/dec/bit_reader.h
+index c06e914..0d20312 100644
+--- a/c/dec/bit_reader.h
++++ b/c/dec/bit_reader.h
+@@ -87,8 +87,11 @@ static BROTLI_INLINE uint32_t BrotliGetAvailableBits(
+ }
+
+ /* Returns amount of unread bytes the bit reader still has buffered from the
+-   BrotliInput, including whole bytes in br->val_. */
++   BrotliInput, including whole bytes in br->val_. Result is capped with
++   maximal ring-buffer size (larger number won't be utilized anyway). */
+ static BROTLI_INLINE size_t BrotliGetRemainingBytes(BrotliBitReader* br) {
++  static const size_t kCap = (size_t)1 << 30;
++  if (br->avail_in > kCap) return kCap;
+   return br->avail_in + (BrotliGetAvailableBits(br) >> 3);
+ }
+
diff --git a/meta-oe/recipes-extended/brotli/brotli_1.0.7.bb b/meta-oe/recipes-extended/brotli/brotli_1.0.7.bb
index 731eaf63a..77fef778a 100644
--- a/meta-oe/recipes-extended/brotli/brotli_1.0.7.bb
+++ b/meta-oe/recipes-extended/brotli/brotli_1.0.7.bb
@@ -6,7 +6,9 @@ BUGTRACKER = "https://github.com/google/brotli/issues"
 LICENSE = "MIT"
 LIC_FILES_CHKSUM = "file://${S}/LICENSE;md5=941ee9cd1609382f946352712a319b4b"
 
-SRC_URI = "git://github.com/google/brotli.git;branch=master;protocol=https"
+SRC_URI = "git://github.com/google/brotli.git;branch=master;protocol=https \
+           file://0001-brotli-fix-CVE-2020-8927.patch \
+           "
 # tag 1.0.7
 SRCREV= "d6d98957ca8ccb1ef45922e978bb10efca0ea541"
 S = "${WORKDIR}/git"