--- /dev/null
+ticket:12888 UText, problems with handling of bad UTF-8
+
+Fixes:
+
+CVE-2017-7867 - International Components for Unicode (ICU) for C/C++ before
+2017-02-13 has an out-of-bounds write caused by a heap-based buffer overflow
+related to the utf8TextAccess function in common/utext.cpp and the
+utext_setNativeIndex* function.
+
+CVE-2017-7868 - International Components for Unicode (ICU) for C/C++ before
+2017-02-13 has an out-of-bounds write caused by a heap-based buffer overflow
+related to the utf8TextAccess function in common/utext.cpp and the
+utext_moveIndex32* function.
+
+Upstream: http://bugs.icu-project.org/trac/changeset/39671
+
+Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
+
+Index: /trunk/icu4c/source/common/utext.cpp
+===================================================================
+--- icu4c/source/common/utext.cpp (revision 39670)
++++ icu4c/source/common/utext.cpp (revision 39671)
+@@ -848,7 +848,13 @@
+
+ // Chunk size.
+-// Must be less than 85, because of byte mapping from UChar indexes to native indexes.
+-// Worst case is three native bytes to one UChar. (Supplemenaries are 4 native bytes
+-// to two UChars.)
++// Must be less than 42 (256/6), because of byte mapping from UChar indexes to native indexes.
++// Worst case there are six UTF-8 bytes per UChar.
++// obsolete 6 byte form fd + 5 trails maps to fffd
++// obsolete 5 byte form fc + 4 trails maps to fffd
++// non-shortest 4 byte forms maps to fffd
++// normal supplementaries map to a pair of utf-16, two utf8 bytes per utf-16 unit
++// mapToUChars array size must allow for the worst case, 6.
++// This could be brought down to 4, by treating fd and fc as pure illegal,
++// rather than obsolete lead bytes. But that is not compatible with the utf-8 access macros.
+ //
+ enum { UTF8_TEXT_CHUNK_SIZE=32 };
+@@ -890,5 +896,5 @@
+ // one for a supplementary starting in the last normal position,
+ // and one for an entry for the buffer limit position.
+- uint8_t mapToUChars[UTF8_TEXT_CHUNK_SIZE*3+6]; // Map native offset from bufNativeStart to
++ uint8_t mapToUChars[UTF8_TEXT_CHUNK_SIZE*6+6]; // Map native offset from bufNativeStart to
+ // correspoding offset in filled part of buf.
+ int32_t align;
+@@ -1033,4 +1039,5 @@
+ u8b = (UTF8Buf *)ut->p; // the current buffer
+ mapIndex = ix - u8b->toUCharsMapStart;
++ U_ASSERT(mapIndex < (int32_t)sizeof(UTF8Buf::mapToUChars));
+ ut->chunkOffset = u8b->mapToUChars[mapIndex] - u8b->bufStartIdx;
+ return TRUE;
+@@ -1299,4 +1306,8 @@
+ // If index is at the end, there is no character there to look at.
+ if (ix != ut->b) {
++ // Note: this function will only move the index back if it is on a trail byte
++ // and there is a preceding lead byte and the sequence from the lead
++ // through this trail could be part of a valid UTF-8 sequence
++ // Otherwise the index remains unchanged.
+ U8_SET_CP_START(s8, 0, ix);
+ }
+@@ -1312,5 +1323,8 @@
+ uint8_t *mapToNative = u8b->mapToNative;
+ uint8_t *mapToUChars = u8b->mapToUChars;
+- int32_t toUCharsMapStart = ix - (UTF8_TEXT_CHUNK_SIZE*3 + 1);
++ int32_t toUCharsMapStart = ix - sizeof(UTF8Buf::mapToUChars) + 1;
++ // Note that toUCharsMapStart can be negative. Happens when the remaining
++ // text from current position to the beginning is less than the buffer size.
++ // + 1 because mapToUChars must have a slot at the end for the bufNativeLimit entry.
+ int32_t destIx = UTF8_TEXT_CHUNK_SIZE+2; // Start in the overflow region
+ // at end of buffer to leave room
+@@ -1339,4 +1353,5 @@
+ // Special case ASCII range for speed.
+ buf[destIx] = (UChar)c;
++ U_ASSERT(toUCharsMapStart <= srcIx);
+ mapToUChars[srcIx - toUCharsMapStart] = (uint8_t)destIx;
+ mapToNative[destIx] = (uint8_t)(srcIx - toUCharsMapStart);
+@@ -1368,4 +1383,5 @@
+ mapToUChars[sIx-- - toUCharsMapStart] = (uint8_t)destIx;
+ } while (sIx >= srcIx);
++ U_ASSERT(toUCharsMapStart <= (srcIx+1));
+
+ // Set native indexing limit to be the current position.
+@@ -1542,4 +1558,5 @@
+ U_ASSERT(index<=ut->chunkNativeLimit);
+ int32_t mapIndex = index - u8b->toUCharsMapStart;
++ U_ASSERT(mapIndex < (int32_t)sizeof(UTF8Buf::mapToUChars));
+ int32_t offset = u8b->mapToUChars[mapIndex] - u8b->bufStartIdx;
+ U_ASSERT(offset>=0 && offset<=ut->chunkLength);
+Index: /trunk/icu4c/source/test/intltest/utxttest.cpp
+===================================================================
+--- icu4c/source/test/intltest/utxttest.cpp (revision 39670)
++++ icu4c/source/test/intltest/utxttest.cpp (revision 39671)
+@@ -68,4 +68,6 @@
+ case 7: name = "Ticket12130";
+ if (exec) Ticket12130(); break;
++ case 8: name = "Ticket12888";
++ if (exec) Ticket12888(); break;
+ default: name = ""; break;
+ }
+@@ -1584,2 +1586,62 @@
+ utext_close(&ut);
+ }
++
++// Ticket 12888: bad handling of illegal utf-8 containing many instances of the archaic, now illegal,
++// six byte utf-8 forms. Original implementation had an assumption that
++// there would be at most three utf-8 bytes per UTF-16 code unit.
++// The five and six byte sequences map to a single replacement character.
++
++void UTextTest::Ticket12888() {
++ const char *badString =
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80"
++ "\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80\xfd\x80\x80\x80\x80\x80";
++
++ UErrorCode status = U_ZERO_ERROR;
++ LocalUTextPointer ut(utext_openUTF8(NULL, badString, -1, &status));
++ TEST_SUCCESS(status);
++ for (;;) {
++ UChar32 c = utext_next32(ut.getAlias());
++ if (c == U_SENTINEL) {
++ break;
++ }
++ }
++ int32_t endIdx = utext_getNativeIndex(ut.getAlias());
++ if (endIdx != (int32_t)strlen(badString)) {
++ errln("%s:%d expected=%d, actual=%d", __FILE__, __LINE__, strlen(badString), endIdx);
++ return;
++ }
++
++ for (int32_t prevIndex = endIdx; prevIndex>0;) {
++ UChar32 c = utext_previous32(ut.getAlias());
++ int32_t currentIndex = utext_getNativeIndex(ut.getAlias());
++ if (c != 0xfffd) {
++ errln("%s:%d (expected, actual, index) = (%d, %d, %d)\n",
++ __FILE__, __LINE__, 0xfffd, c, currentIndex);
++ break;
++ }
++ if (currentIndex != prevIndex - 6) {
++ errln("%s:%d: wrong index. Expected, actual = %d, %d",
++ __FILE__, __LINE__, prevIndex - 6, currentIndex);
++ break;
++ }
++ prevIndex = currentIndex;
++ }
++}
+Index: /trunk/icu4c/source/test/intltest/utxttest.h
+===================================================================
+--- icu4c/source/test/intltest/utxttest.h (revision 39670)
++++ icu4c/source/test/intltest/utxttest.h (revision 39671)
+@@ -39,4 +39,5 @@
+ void Ticket10983();
+ void Ticket12130();
++ void Ticket12888();
+
+ private:
projects / buildroot.git / commitdiff