1 files changed, 53 insertions, 0 deletions

diff --git a/meta/recipes-multimedia/webp/files/CVE-2023-4863-0002.patch b/meta/recipes-multimedia/webp/files/CVE-2023-4863-0002.patch
new file mode 100644
index 0000000000..c1eedb6100
--- /dev/null
+++ b/meta/recipes-multimedia/webp/files/CVE-2023-4863-0002.patch
@@ -0,0 +1,53 @@
+From 95ea5226c870449522240ccff26f0b006037c520 Mon Sep 17 00:00:00 2001
+From: Vincent Rabaud <vrabaud@google.com>
+Date: Mon, 11 Sep 2023 16:06:08 +0200
+Subject: [PATCH 2/2] Fix invalid incremental decoding check.
+
+The first condition is only necessary if we have not read enough
+(enough being defined by src_last, not src_end which is the end
+of the image).
+The second condition now fits the comment below: "if not
+incremental, and we are past the end of buffer".
+
+BUG=oss-fuzz:62136
+
+Change-Id: I0700f67c62db8e1c02c2e429a069a71e606a5e4f
+
+CVE: CVE-2023-4863
+
+Upstream-Status: Backport [https://github.com/webmproject/libwebp/commit/95ea5226c870449522240ccff26f0b006037c520]
+
+Signed-off-by: Soumya Sambu <soumya.sambu@windriver.com>
+---
+ src/dec/vp8l_dec.c | 15 +++++++++++++--
+ 1 file changed, 13 insertions(+), 2 deletions(-)
+
+diff --git a/src/dec/vp8l_dec.c b/src/dec/vp8l_dec.c
+index 0d38314..684a5b6 100644
+--- a/src/dec/vp8l_dec.c
++++ b/src/dec/vp8l_dec.c
+@@ -1237,9 +1237,20 @@ static int DecodeImageData(VP8LDecoder* const dec, uint32_t* const data,
+   }
+
+   br->eos_ = VP8LIsEndOfStream(br);
+-  if (dec->incremental_ && br->eos_ && src < src_end) {
++  // In incremental decoding:
++  // br->eos_ && src < src_last: if 'br' reached the end of the buffer and
++  // 'src_last' has not been reached yet, there is not enough data. 'dec' has to
++  // be reset until there is more data.
++  // !br->eos_ && src < src_last: this cannot happen as either the buffer is
++  // fully read, either enough has been read to reach 'src_last'.
++  // src >= src_last: 'src_last' is reached, all is fine. 'src' can actually go
++  // beyond 'src_last' in case the image is cropped and an LZ77 goes further.
++  // The buffer might have been enough or there is some left. 'br->eos_' does
++  // not matter.
++  assert(!dec->incremental_ || (br->eos_ && src < src_last) || src >= src_last);
++  if (dec->incremental_ && br->eos_ && src < src_last) {
+     RestoreState(dec);
+-  } else if (!br->eos_) {
++  } else if ((dec->incremental_ && src >= src_last) || !br->eos_) {
+     // Process the remaining rows corresponding to last row-block.
+     if (process_func != NULL) {
+       process_func(dec, row > last_row ? last_row : row);
+--
+2.40.0