From bfed843041b6aaec13ee19996748a7a1476db9c8 Mon Sep 17 00:00:00 2001 From: Lajos Molnar Date: Wed, 1 Apr 2015 19:32:25 -0700 Subject: [PATCH] Add AUtils::isInRange, and use it to detect malformed MPEG4 nal sizes Bug: 19641538 Change-Id: I5aae3f100846c125decc61eec7cd6563e3f33777 --- include/media/stagefright/foundation/AUtils.h | 22 ++++++++ media/libstagefright/MPEG4Extractor.cpp | 12 ++-- media/libstagefright/tests/Utils_test.cpp | 81 +++++++++++++++++++++++++++ 3 files changed, 109 insertions(+), 6 deletions(-) diff --git a/include/media/stagefright/foundation/AUtils.h b/include/media/stagefright/foundation/AUtils.h index 3a73a39343..255bcbe7f8 100644 --- a/include/media/stagefright/foundation/AUtils.h +++ b/include/media/stagefright/foundation/AUtils.h @@ -55,6 +55,28 @@ inline static const T &max(const T &a, const T &b) { return a > b ? a : b; } +template +void ENSURE_UNSIGNED_TYPE() { + T TYPE_MUST_BE_UNSIGNED[(T)-1 < 0 ? -1 : 0] __unused; +} + +// needle is in range [hayStart, hayStart + haySize) +template +inline static bool isInRange(const T &hayStart, const U &haySize, const T &needle) { + ENSURE_UNSIGNED_TYPE(); + return (T)(hayStart + haySize) >= hayStart && needle >= hayStart && (U)(needle - hayStart) < haySize; +} + +// [needleStart, needleStart + needleSize) is in range [hayStart, hayStart + haySize) +template +inline static bool isInRange( + const T &hayStart, const U &haySize, const T &needleStart, const U &needleSize) { + ENSURE_UNSIGNED_TYPE(); + return isInRange(hayStart, haySize, needleStart) + && (T)(needleStart + needleSize) >= needleStart + && (U)(needleStart + needleSize - hayStart) <= haySize; +} + /* T must be integer type, period must be positive */ template inline static T periodicError(const T &val, const T &period) { diff --git a/media/libstagefright/MPEG4Extractor.cpp b/media/libstagefright/MPEG4Extractor.cpp index d922dc096e..080dcd140f 100644 --- a/media/libstagefright/MPEG4Extractor.cpp +++ b/media/libstagefright/MPEG4Extractor.cpp @@ -33,6 +33,7 @@ #include #include #include +#include #include #include #include @@ -221,8 +222,7 @@ status_t MPEG4DataSource::initCheck() const { ssize_t MPEG4DataSource::readAt(off64_t offset, void *data, size_t size) { Mutex::Autolock autoLock(mLock); - if (offset >= mCachedOffset - && offset + size <= mCachedOffset + mCachedSize) { + if (isInRange(mCachedOffset, mCachedSize, offset, size)) { memcpy(data, &mCache[offset - mCachedOffset], size); return size; } @@ -3879,12 +3879,12 @@ status_t MPEG4Source::read( size_t dstOffset = 0; while (srcOffset < size) { - bool isMalFormed = (srcOffset + mNALLengthSize > size); + bool isMalFormed = !isInRange((size_t)0u, size, srcOffset, mNALLengthSize); size_t nalLength = 0; if (!isMalFormed) { nalLength = parseNALSize(&mSrcBuffer[srcOffset]); srcOffset += mNALLengthSize; - isMalFormed = srcOffset + nalLength > size; + isMalFormed = !isInRange((size_t)0u, size, srcOffset, nalLength); } if (isMalFormed) { @@ -4156,12 +4156,12 @@ status_t MPEG4Source::fragmentedRead( size_t dstOffset = 0; while (srcOffset < size) { - bool isMalFormed = (srcOffset + mNALLengthSize > size); + bool isMalFormed = !isInRange((size_t)0u, size, srcOffset, mNALLengthSize); size_t nalLength = 0; if (!isMalFormed) { nalLength = parseNALSize(&mSrcBuffer[srcOffset]); srcOffset += mNALLengthSize; - isMalFormed = srcOffset + nalLength > size; + isMalFormed = !isInRange((size_t)0u, size, srcOffset, nalLength); } if (isMalFormed) { diff --git a/media/libstagefright/tests/Utils_test.cpp b/media/libstagefright/tests/Utils_test.cpp index f2825ddc88..1c13f19503 100644 --- a/media/libstagefright/tests/Utils_test.cpp +++ b/media/libstagefright/tests/Utils_test.cpp @@ -90,6 +90,87 @@ TEST_F(UtilsTest, TestMathTemplates) { ASSERT_EQ(max(-4.3, 8.6), 8.6); ASSERT_EQ(max(8.6, -4.3), 8.6); + ASSERT_FALSE(isInRange(-43, 86u, -44)); + ASSERT_TRUE(isInRange(-43, 87u, -43)); + ASSERT_TRUE(isInRange(-43, 88u, -1)); + ASSERT_TRUE(isInRange(-43, 89u, 0)); + ASSERT_TRUE(isInRange(-43, 90u, 46)); + ASSERT_FALSE(isInRange(-43, 91u, 48)); + ASSERT_FALSE(isInRange(-43, 92u, 50)); + + ASSERT_FALSE(isInRange(43, 86u, 42)); + ASSERT_TRUE(isInRange(43, 87u, 43)); + ASSERT_TRUE(isInRange(43, 88u, 44)); + ASSERT_TRUE(isInRange(43, 89u, 131)); + ASSERT_FALSE(isInRange(43, 90u, 133)); + ASSERT_FALSE(isInRange(43, 91u, 135)); + + ASSERT_FALSE(isInRange(43u, 86u, 42u)); + ASSERT_TRUE(isInRange(43u, 85u, 43u)); + ASSERT_TRUE(isInRange(43u, 84u, 44u)); + ASSERT_TRUE(isInRange(43u, 83u, 125u)); + ASSERT_FALSE(isInRange(43u, 82u, 125u)); + ASSERT_FALSE(isInRange(43u, 81u, 125u)); + + ASSERT_FALSE(isInRange(-43, ~0u, 43)); + ASSERT_FALSE(isInRange(-43, ~0u, 44)); + ASSERT_FALSE(isInRange(-43, ~0u, ~0)); + ASSERT_FALSE(isInRange(-43, ~0u, 41)); + ASSERT_FALSE(isInRange(-43, ~0u, 40)); + + ASSERT_FALSE(isInRange(43u, ~0u, 43u)); + ASSERT_FALSE(isInRange(43u, ~0u, 41u)); + ASSERT_FALSE(isInRange(43u, ~0u, 40u)); + ASSERT_FALSE(isInRange(43u, ~0u, ~0u)); + + ASSERT_FALSE(isInRange(-43, 86u, -44, 0u)); + ASSERT_FALSE(isInRange(-43, 86u, -44, 1u)); + ASSERT_FALSE(isInRange(-43, 86u, -44, 2u)); + ASSERT_FALSE(isInRange(-43, 86u, -44, ~0u)); + ASSERT_TRUE(isInRange(-43, 87u, -43, 0u)); + ASSERT_TRUE(isInRange(-43, 87u, -43, 1u)); + ASSERT_TRUE(isInRange(-43, 87u, -43, 86u)); + ASSERT_TRUE(isInRange(-43, 87u, -43, 87u)); + ASSERT_FALSE(isInRange(-43, 87u, -43, 88u)); + ASSERT_FALSE(isInRange(-43, 87u, -43, ~0u)); + ASSERT_TRUE(isInRange(-43, 88u, -1, 0u)); + ASSERT_TRUE(isInRange(-43, 88u, -1, 45u)); + ASSERT_TRUE(isInRange(-43, 88u, -1, 46u)); + ASSERT_FALSE(isInRange(-43, 88u, -1, 47u)); + ASSERT_FALSE(isInRange(-43, 88u, -1, ~3u)); + ASSERT_TRUE(isInRange(-43, 90u, 46, 0u)); + ASSERT_TRUE(isInRange(-43, 90u, 46, 1u)); + ASSERT_FALSE(isInRange(-43, 90u, 46, 2u)); + ASSERT_FALSE(isInRange(-43, 91u, 48, 0u)); + ASSERT_FALSE(isInRange(-43, 91u, 48, 2u)); + ASSERT_FALSE(isInRange(-43, 91u, 48, ~6u)); + ASSERT_FALSE(isInRange(-43, 92u, 50, 0u)); + ASSERT_FALSE(isInRange(-43, 92u, 50, 1u)); + + ASSERT_FALSE(isInRange(43u, 86u, 42u, 0u)); + ASSERT_FALSE(isInRange(43u, 86u, 42u, 1u)); + ASSERT_FALSE(isInRange(43u, 86u, 42u, 2u)); + ASSERT_FALSE(isInRange(43u, 86u, 42u, ~0u)); + ASSERT_TRUE(isInRange(43u, 87u, 43u, 0u)); + ASSERT_TRUE(isInRange(43u, 87u, 43u, 1u)); + ASSERT_TRUE(isInRange(43u, 87u, 43u, 86u)); + ASSERT_TRUE(isInRange(43u, 87u, 43u, 87u)); + ASSERT_FALSE(isInRange(43u, 87u, 43u, 88u)); + ASSERT_FALSE(isInRange(43u, 87u, 43u, ~0u)); + ASSERT_TRUE(isInRange(43u, 88u, 60u, 0u)); + ASSERT_TRUE(isInRange(43u, 88u, 60u, 70u)); + ASSERT_TRUE(isInRange(43u, 88u, 60u, 71u)); + ASSERT_FALSE(isInRange(43u, 88u, 60u, 72u)); + ASSERT_FALSE(isInRange(43u, 88u, 60u, ~3u)); + ASSERT_TRUE(isInRange(43u, 90u, 132u, 0u)); + ASSERT_TRUE(isInRange(43u, 90u, 132u, 1u)); + ASSERT_FALSE(isInRange(43u, 90u, 132u, 2u)); + ASSERT_FALSE(isInRange(43u, 91u, 134u, 0u)); + ASSERT_FALSE(isInRange(43u, 91u, 134u, 2u)); + ASSERT_FALSE(isInRange(43u, 91u, 134u, ~6u)); + ASSERT_FALSE(isInRange(43u, 92u, 136u, 0u)); + ASSERT_FALSE(isInRange(43u, 92u, 136u, 1u)); + ASSERT_EQ(periodicError(124, 100), 24); ASSERT_EQ(periodicError(288, 100), 12); ASSERT_EQ(periodicError(-345, 100), 45); -- 2.11.0