Commit 1ba18717 authored by Jingning Han's avatar Jingning Han

Fix out of boundary memory read in fuzz test on vpxdec

This commit fixes frame header decoding for superframe index, to
prevent out of boundary memory read triggered by fuzz test
vector. It resolves a chromium security violation issue
crbug.com/376802.

The issue was introduced in the change:

Add VPXD_SET_DECRYPTOR support to the VP9 decoder.
cl-id I88f86c8ff9af34e0b6531028b691921b54c2fc48

where the buffer was read before validation check on index offset
applied.

A test vector is added accordingly.

Change-Id: I41c988e776bbdd1033312a668e03a3dbcf44ca99
parent 5556d118
......@@ -639,4 +639,5 @@ e615575ded499ea1d992f3b38e3baa434509cdcd vp90-2-15-segkey.webm
e3ab35d4316c5e81325c50f5236ceca4bc0d35df vp90-2-15-segkey.webm.md5
9b7ca2cac09d34c4a5d296c1900f93b1e2f69d0d vp90-2-15-segkey_adpq.webm
8f46ba5f785d0c2170591a153e0d0d146a7c8090 vp90-2-15-segkey_adpq.webm.md5
d78e2fceba5ac942246503ec8366f879c4775ca5 vp90-2-15-fuzz-flicker.webm
bbd7dd15f43a703ff0a332fee4959e7b23bf77dc vp90-2-15-fuzz-flicker.webm.md5
......@@ -755,6 +755,8 @@ LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += vp90-2-15-segkey.webm
LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += vp90-2-15-segkey.webm.md5
LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += vp90-2-15-segkey_adpq.webm
LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += vp90-2-15-segkey_adpq.webm.md5
LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += vp90-2-15-fuzz-flicker.webm
LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += vp90-2-15-fuzz-flicker.webm.md5
ifeq ($(CONFIG_DECODE_PERF_TESTS),yes)
# BBB VP9 streams
......
......@@ -178,7 +178,8 @@ const char *const kVP9TestVectors[] = {
"vp90-2-14-resize-fp-tiles-4-2.webm", "vp90-2-14-resize-fp-tiles-4-8.webm",
"vp90-2-14-resize-fp-tiles-8-16.webm", "vp90-2-14-resize-fp-tiles-8-1.webm",
"vp90-2-14-resize-fp-tiles-8-2.webm", "vp90-2-14-resize-fp-tiles-8-4.webm",
"vp90-2-15-segkey.webm", "vp90-2-15-segkey_adpq.webm"
"vp90-2-15-segkey.webm", "vp90-2-15-segkey_adpq.webm",
"vp90-2-15-fuzz-flicker.webm"
};
const int kNumVP9TestVectors = NELEMENTS(kVP9TestVectors);
#endif // CONFIG_VP9_DECODER
......
......@@ -312,15 +312,16 @@ static void parse_superframe_index(const uint8_t *data, size_t data_sz,
const uint32_t mag = ((marker >> 3) & 0x3) + 1;
const size_t index_sz = 2 + mag * frames;
if (data_sz >= index_sz) {
uint8_t marker2 = read_marker(decrypt_cb, decrypt_state,
data + data_sz - index_sz);
if (data_sz >= index_sz && marker2 == marker) {
// found a valid superframe index
if (marker == marker2) {
// Found a valid superframe index.
uint32_t i, j;
const uint8_t *x = &data[data_sz - index_sz + 1];
// frames has a maximum of 8 and mag has a maximum of 4.
// Frames has a maximum of 8 and mag has a maximum of 4.
uint8_t clear_buffer[32];
assert(sizeof(clear_buffer) >= frames * mag);
if (decrypt_cb) {
......@@ -328,10 +329,10 @@ static void parse_superframe_index(const uint8_t *data, size_t data_sz,
x = clear_buffer;
}
for (i = 0; i < frames; i++) {
for (i = 0; i < frames; ++i) {
uint32_t this_sz = 0;
for (j = 0; j < mag; j++)
for (j = 0; j < mag; ++j)
this_sz |= (*x++) << (j * 8);
sizes[i] = this_sz;
}
......@@ -339,6 +340,7 @@ static void parse_superframe_index(const uint8_t *data, size_t data_sz,
*count = frames;
}
}
}
}
static vpx_codec_err_t decode_one_iter(vpx_codec_alg_priv_t *ctx,
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment