icu: fix CVE-2020-10531

FIX CVE-2020-10531
 An integer overflow, leading to a heap-based buffer overflow, exists in the UnicodeString::doAppend() function in common/unistr.cpp.

Signed-off-by: Hirokazu MORIKAWA <morikw2@gmail.com>

diff --git a/libs/icu/Makefile b/libs/icu/Makefile
index f3cc0cff771f07e54fae2d6924f11b98c86396ed..4681a7ddcfd71fbce36452ec24f26f761d24304c 100644 (file)
--- a/libs/icu/Makefile
+++ b/libs/icu/Makefile
@@ -11,7 +11,7 @@ PKG_NAME:=icu4c
 MAJOR_VERSION:=61
 MINOR_VERSION:=2
 PKG_VERSION:=$(MAJOR_VERSION).$(MINOR_VERSION)
-PKG_RELEASE:=4
+PKG_RELEASE:=5
 
 PKG_SOURCE:=$(PKG_NAME)-$(MAJOR_VERSION)_$(MINOR_VERSION)-src.tgz
 PKG_SOURCE_URL:=https://github.com/unicode-org/icu/releases/download/release-$(MAJOR_VERSION)-$(MINOR_VERSION)

diff --git a/libs/icu/patches/030-CVE-2020-10531.patch b/libs/icu/patches/030-CVE-2020-10531.patch
new file mode 100644 (file)
index 0000000..a369ff7
--- /dev/null
+++ b/libs/icu/patches/030-CVE-2020-10531.patch
@@ -0,0 +1,132 @@
+Backported of:
+
+From b7d08bc04a4296982fcef8b6b8a354a9e4e7afca Mon Sep 17 00:00:00 2001
+From: Frank Tang <ftang@chromium.org>
+Date: Sat, 1 Feb 2020 02:39:04 +0000
+Subject: [PATCH] ICU-20958 Prevent SEGV_MAPERR in append
+
+See #971
+diff --git a/source/common/unistr.cpp b/source/common/unistr.cpp
+index 1bfb71a..e8a7f12 100644
+--- a/common/unistr.cpp
++++ b/common/unistr.cpp
+@@ -75,6 +75,17 @@ print(const UChar *s,
+ // END DEBUGGING
+ #endif
+ 
++// Adding this function as support of CVE-2020-10531
++// since this version has not uprv_add32_overflow
++// implement it here.
++UBool uprv_add32_overflow(int32_t a, int32_t b, int32_t* res) {
++  auto a64 = static_cast<int64_t>(a);
++  auto b64 = static_cast<int64_t>(b);
++  int64_t res64 = a64 + b64;
++  *res = static_cast<int32_t>(res64);
++  return res64 != *res;
++}
++
+ // Local function definitions for now
+ 
+ // need to copy areas that may overlap
+@@ -1544,7 +1555,11 @@ UnicodeString::doAppend(const UChar *srcChars, int32_t srcStart, int32_t srcLeng
+   }
+ 
+   int32_t oldLength = length();
+-  int32_t newLength = oldLength + srcLength;
++  int32_t newLength;
++  if (uprv_add32_overflow(oldLength, srcLength, &newLength)) {
++    setToBogus();
++    return *this;
++  }
+   // optimize append() onto a large-enough, owned string
+   if((newLength <= getCapacity() && isBufferWritable()) ||
+       cloneArrayIfNeeded(newLength, getGrowCapacity(newLength))) {
+diff --git a/source/test/intltest/ustrtest.cpp b/source/test/intltest/ustrtest.cpp
+index b361e20..9b613d3 100644
+--- a/test/intltest/ustrtest.cpp
++++ b/test/intltest/ustrtest.cpp
+@@ -64,6 +64,7 @@ void UnicodeStringTest::runIndexedTest( int32_t index, UBool exec, const char* &
+     TESTCASE_AUTO(TestUInt16Pointers);
+     TESTCASE_AUTO(TestWCharPointers);
+     TESTCASE_AUTO(TestNullPointers);
++    TESTCASE_AUTO(TestLargeAppend);
+     TESTCASE_AUTO_END;
+ }
+ 
+@@ -2248,3 +2249,64 @@ UnicodeStringTest::TestNullPointers() {
+     UnicodeString(u"def").extract(nullptr, 0, errorCode);
+     assertEquals("buffer overflow extracting to nullptr", U_BUFFER_OVERFLOW_ERROR, errorCode);
+ }
++
++void UnicodeStringTest::TestLargeAppend() {
++    if(quick) return;
++
++    IcuTestErrorCode status(*this, "TestLargeAppend");
++    // Make a large UnicodeString
++    int32_t len = 0xAFFFFFF;
++    UnicodeString str;
++    char16_t *buf = str.getBuffer(len);
++    // A fast way to set buffer to valid Unicode.
++    // 4E4E is a valid unicode character
++    uprv_memset(buf, 0x4e, len * 2);
++    str.releaseBuffer(len);
++    UnicodeString dest;
++    // Append it 16 times
++    // 0xAFFFFFF times 16 is 0xA4FFFFF1,
++    // which is greater than INT32_MAX, which is 0x7FFFFFFF.
++    int64_t total = 0;
++    for (int32_t i = 0; i < 16; i++) {
++        dest.append(str);
++        total += len;
++        if (total <= INT32_MAX) {
++            assertFalse("dest is not bogus", dest.isBogus());
++        } else {
++            assertTrue("dest should be bogus", dest.isBogus());
++        }
++    }
++    dest.remove();
++    total = 0;
++    for (int32_t i = 0; i < 16; i++) {
++        dest.append(str);
++        total += len;
++        if (total + len <= INT32_MAX) {
++            assertFalse("dest is not bogus", dest.isBogus());
++        } else if (total <= INT32_MAX) {
++            // Check that a string of exactly the maximum size works
++            UnicodeString str2;
++            int32_t remain = INT32_MAX - total;
++            char16_t *buf2 = str2.getBuffer(remain);
++            if (buf2 == nullptr) {
++                // if somehow memory allocation fail, return the test
++                return;
++            }
++            uprv_memset(buf2, 0x4e, remain * 2);
++            str2.releaseBuffer(remain);
++            dest.append(str2);
++            total += remain;
++            assertEquals("When a string of exactly the maximum size works", (int64_t)INT32_MAX, total);
++            assertEquals("When a string of exactly the maximum size works", INT32_MAX, dest.length());
++            assertFalse("dest is not bogus", dest.isBogus());
++
++            // Check that a string size+1 goes bogus
++            str2.truncate(1);
++            dest.append(str2);
++            total++;
++            assertTrue("dest should be bogus", dest.isBogus());
++        } else {
++            assertTrue("dest should be bogus", dest.isBogus());
++        }
++    }
++}
+diff --git a/source/test/intltest/ustrtest.h b/source/test/intltest/ustrtest.h
+index 4ba348c..d2d5ee1 100644
+--- a/test/intltest/ustrtest.h
++++ b/test/intltest/ustrtest.h
+@@ -96,6 +96,7 @@ public:
+     void TestUInt16Pointers();
+     void TestWCharPointers();
+     void TestNullPointers();
++    void TestLargeAppend();
+ };
+ 
+ #endif