CVE-2023-5217 (published 2023-09-28T16:15Z)

Heap buffer overflow in vp8 encoding in libvpx in Google Chrome prior to 117.0.5938.132 and libvpx 1.13.1 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. (Chromium security severity: High)

CVSS v3 base score: 8.8, HIGH (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)

Weakness information:
cwe_id: CWE-787
cwe_name: Out-of-bounds Write
description: The product writes data past the end, or before the beginning, of the intended buffer.
extended_description: 
            
            
             
			 
         
         

Fix information:
repo_url: https://github.com/webmproject/libvpx
commit_details: repo_url: https://github.com/webmproject/libvpx
author: James Zern
author_date: 2023-09-25 18:53:41-07:00
msg: encode_api_test: add ConfigResizeChangeThreadCount

Update thread counts and resolution to ensure allocations are updated
correctly. VP8 is disabled to avoid a crash.

Bug: chromium:1486441
Change-Id: Ie89776d9818d27dc351eff298a44c699e850761b
repository: repo_url: https://github.com/webmproject/libvpx
repo_name: webmproject/libvpx
description: Mirror only. Please do not send pull requests.
repo_language: C
owner: webmproject
file_changes: filename: encode_api_test.cc
change_type: ModificationType.MODIFY
diff: @@ -308,7 +308,6 @@ TEST(EncodeAPI, SetRoi) {
 
 void InitCodec(const vpx_codec_iface_t &iface, int width, int height,
                vpx_codec_ctx_t *enc, vpx_codec_enc_cfg_t *cfg) {
-  ASSERT_EQ(vpx_codec_enc_config_default(&iface, cfg, 0), VPX_CODEC_OK);
   cfg->g_w = width;
   cfg->g_h = height;
   cfg->g_lag_in_frames = 0;
@@ -346,6 +345,7 @@ TEST(EncodeAPI, ConfigChangeThreadCount) {
         vpx_codec_ctx_t ctx = {};
       } enc;
 
+      ASSERT_EQ(vpx_codec_enc_config_default(iface, &cfg, 0), VPX_CODEC_OK);
       EXPECT_NO_FATAL_FAILURE(
           InitCodec(*iface, kWidth, kHeight, &enc.ctx, &cfg));
       if (IsVP9(iface)) {
@@ -364,6 +364,54 @@ TEST(EncodeAPI, ConfigChangeThreadCount) {
   }
 }
 
+TEST(EncodeAPI, ConfigResizeChangeThreadCount) {
+  constexpr int kInitWidth = 1024;
+  constexpr int kInitHeight = 1024;
+
+  for (const auto *iface : kCodecIfaces) {
+    SCOPED_TRACE(vpx_codec_iface_name(iface));
+    if (!IsVP9(iface)) {
+      GTEST_SKIP() << "TODO(https://crbug.com/1486441) remove this condition "
+                      "after VP8 is fixed.";
+    }
+    for (int i = 0; i < (IsVP9(iface) ? 2 : 1); ++i) {
+      vpx_codec_enc_cfg_t cfg = {};
+      struct Encoder {
+        ~Encoder() { EXPECT_EQ(vpx_codec_destroy(&ctx), VPX_CODEC_OK); }
+        vpx_codec_ctx_t ctx = {};
+      } enc;
+
+      ASSERT_EQ(vpx_codec_enc_config_default(iface, &cfg, 0), VPX_CODEC_OK);
+      // Start in threaded mode to ensure resolution and thread related
+      // allocations are updated correctly across changes in resolution and
+      // thread counts. See https://crbug.com/1486441.
+      cfg.g_threads = 4;
+      EXPECT_NO_FATAL_FAILURE(
+          InitCodec(*iface, kInitWidth, kInitHeight, &enc.ctx, &cfg));
+      if (IsVP9(iface)) {
+        EXPECT_EQ(vpx_codec_control_(&enc.ctx, VP9E_SET_TILE_COLUMNS, 6),
+                  VPX_CODEC_OK);
+        EXPECT_EQ(vpx_codec_control_(&enc.ctx, VP9E_SET_ROW_MT, i),
+                  VPX_CODEC_OK);
+      }
+
+      cfg.g_w = 1000;
+      cfg.g_h = 608;
+      EXPECT_EQ(vpx_codec_enc_config_set(&enc.ctx, &cfg), VPX_CODEC_OK)
+          << vpx_codec_error_detail(&enc.ctx);
+
+      cfg.g_w = 16;
+      cfg.g_h = 720;
+
+      for (const auto threads : { 1, 4, 8, 6, 2, 1 }) {
+        cfg.g_threads = threads;
+        EXPECT_NO_FATAL_FAILURE(EncodeWithConfig(cfg, &enc.ctx))
+            << "iteration: " << i << " threads: " << threads;
+      }
+    }
+  }
+}
+
 #if CONFIG_VP9_ENCODER
 class EncodeApiGetTplStatsTest
     : public ::libvpx_test::EncoderTest,

programming_language: C
repo_url: https://github.com/webmproject/libvpx
commit_details: repo_url: https://github.com/webmproject/libvpx
author: James Zern
author_date: 2023-09-25 18:55:59-07:00
msg: VP8: disallow thread count changes

Currently allocations are done at encoder creation time. Going from
threaded to non-threaded would cause a crash.

Bug: chromium:1486441
Change-Id: Ie301c2a70847dff2f0daae408fbef1e4d42e73d4
repository: repo_url: https://github.com/webmproject/libvpx
repo_name: webmproject/libvpx
description: Mirror only. Please do not send pull requests.
repo_language: C
owner: webmproject
file_changes: filename: encode_api_test.cc
change_type: ModificationType.MODIFY
diff: @@ -370,10 +370,6 @@ TEST(EncodeAPI, ConfigResizeChangeThreadCount) {
 
   for (const auto *iface : kCodecIfaces) {
     SCOPED_TRACE(vpx_codec_iface_name(iface));
-    if (!IsVP9(iface)) {
-      GTEST_SKIP() << "TODO(https://crbug.com/1486441) remove this condition "
-                      "after VP8 is fixed.";
-    }
     for (int i = 0; i < (IsVP9(iface) ? 2 : 1); ++i) {
       vpx_codec_enc_cfg_t cfg = {};
       struct Encoder {

programming_language: C
filename: onyx_if.c
change_type: ModificationType.MODIFY
diff: @@ -1447,6 +1447,11 @@ void vp8_change_config(VP8_COMP *cpi, VP8_CONFIG *oxcf) {
   last_h = cpi->oxcf.Height;
   prev_number_of_layers = cpi->oxcf.number_of_layers;
 
+  if (cpi->initial_width) {
+    // TODO(https://crbug.com/1486441): Allow changing thread counts; the
+    // allocation is done once in vp8_create_compressor().
+    oxcf->multi_threaded = cpi->oxcf.multi_threaded;
+  }
   cpi->oxcf = *oxcf;
 
   switch (cpi->oxcf.Mode) {

programming_language: C