From 1bd967f9a87ee6a34332721830c9e720f43a3e9b Mon Sep 17 00:00:00 2001 From: Edwin Wong Date: Tue, 2 Feb 2021 12:55:27 -0800 Subject: [PATCH] [RESTRICT AUTOMERGE] 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: Ic511871dfa3ddf7e66e94f7d58c4c9558add09a2 --- libwvdrmengine/mediacrypto/src_hidl/WVCryptoPlugin.cpp | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/libwvdrmengine/mediacrypto/src_hidl/WVCryptoPlugin.cpp b/libwvdrmengine/mediacrypto/src_hidl/WVCryptoPlugin.cpp index 75b02259..a97a6fa1 100644 --- a/libwvdrmengine/mediacrypto/src_hidl/WVCryptoPlugin.cpp +++ b/libwvdrmengine/mediacrypto/src_hidl/WVCryptoPlugin.cpp @@ -171,7 +171,10 @@ Return WVCryptoPlugin::decrypt( return Void(); } - if (destBuffer.offset + destBuffer.size > destBase->getSize()) { + size_t totalDstSize = 0; + if (__builtin_add_overflow(destBuffer.offset, destBuffer.size, &totalDstSize) || + totalDstSize > destBase->getSize()) { + android_errorWriteLog(0x534e4554, "176444622"); _hidl_cb(Status::ERROR_DRM_CANNOT_HANDLE, 0, "invalid buffer size"); return Void(); }