diff options
| author | Edwin Wong <edwinwong@google.com> | 2021-02-02 21:36:34 -0800 |
|---|---|---|
| committer | Edwin Wong <edwinwong@google.com> | 2021-02-25 17:53:57 +0000 |
| commit | 49c0fe413ceb2e0cef356d2738d63bb873845e04 (patch) | |
| tree | 9a3f013fcb9373b65ace30e33ab32a5afd15ec76 | |
| parent | 23a3c612893597b2c1d6507ef9c94ae25f8cdcbe (diff) | |
Fix potential decrypt destPtr overflow.
There is a potential integer overflow to bypass the
destination base size check in decrypt. The destPtr
can then point to the outside of the destination buffer.
Test: sts-tradefed
sts-tradefed run sts-engbuild-no-spl-lock -m StsHostTestCases --test android.security.sts.Bug_176444622#testPocBug_176444622
Test: push to device with target_hwasan-userdebug build
adb shell /data/local/tmp/Bug-17644462264
Bug: 176444622
Bug: 176496353
Change-Id: Idac48307edd45fc8282902c4beeb2c8ca94f8cf3
Merged-In: Idac48307edd45fc8282902c4beeb2c8ca94f8cf3
| -rw-r--r-- | drm/mediadrm/plugins/clearkey/hidl/CryptoPlugin.cpp | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drm/mediadrm/plugins/clearkey/hidl/CryptoPlugin.cpp b/drm/mediadrm/plugins/clearkey/hidl/CryptoPlugin.cpp index d278633482..005e551383 100644 --- a/drm/mediadrm/plugins/clearkey/hidl/CryptoPlugin.cpp +++ b/drm/mediadrm/plugins/clearkey/hidl/CryptoPlugin.cpp @@ -142,12 +142,14 @@ Return<void> CryptoPlugin::decrypt_1_2( base = static_cast<uint8_t *>(static_cast<void *>(destBase->getPointer())); - if (destBuffer.offset + destBuffer.size > destBase->getSize()) { + totalSize = 0; + if (__builtin_add_overflow(destBuffer.offset, destBuffer.size, &totalSize) || + totalSize > destBase->getSize()) { + android_errorWriteLog(0x534e4554, "176444622"); _hidl_cb(Status_V1_2::ERROR_DRM_FRAME_TOO_LARGE, 0, "invalid buffer size"); return Void(); } - destPtr = static_cast<void *>(base + destination.nonsecureMemory.offset); - + destPtr = static_cast<void*>(base + destination.nonsecureMemory.offset); // Calculate the output buffer size and determine if any subsamples are // encrypted. |