Fix integer overflow in utf{16,32}_to_utf8_length

am: 47efc676c8

Change-Id: Id54a1e644fc02a2923c6bf165205d16e43cf5eb2
This commit is contained in:
Adam Vartanian 2017-09-11 09:26:42 +00:00 committed by android-build-merger
commit 6e2bf89dc7
1 changed files with 20 additions and 3 deletions

View File

@ -180,7 +180,15 @@ ssize_t utf32_to_utf8_length(const char32_t *src, size_t src_len)
size_t ret = 0;
const char32_t *end = src + src_len;
while (src < end) {
ret += utf32_codepoint_utf8_length(*src++);
size_t char_len = utf32_codepoint_utf8_length(*src++);
if (SSIZE_MAX - char_len < ret) {
// If this happens, we would overflow the ssize_t type when
// returning from this function, so we cannot express how
// long this string is in an ssize_t.
android_errorWriteLog(0x534e4554, "37723026");
return -1;
}
ret += char_len;
}
return ret;
}
@ -440,14 +448,23 @@ ssize_t utf16_to_utf8_length(const char16_t *src, size_t src_len)
size_t ret = 0;
const char16_t* const end = src + src_len;
while (src < end) {
size_t char_len;
if ((*src & 0xFC00) == 0xD800 && (src + 1) < end
&& (*(src + 1) & 0xFC00) == 0xDC00) {
// surrogate pairs are always 4 bytes.
ret += 4;
char_len = 4;
src += 2;
} else {
ret += utf32_codepoint_utf8_length((char32_t) *src++);
char_len = utf32_codepoint_utf8_length((char32_t)*src++);
}
if (SSIZE_MAX - char_len < ret) {
// If this happens, we would overflow the ssize_t type when
// returning from this function, so we cannot express how
// long this string is in an ssize_t.
android_errorWriteLog(0x534e4554, "37723026");
return -1;
}
ret += char_len;
}
return ret;
}