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authorRyan Harrison <rharrison@chromium.org>2018-06-21 18:29:44 +0000
committerChromium commit bot <commit-bot@chromium.org>2018-06-21 18:29:44 +0000
commitd52a0afaa3e4374dee469e41db4389bf9c61c4a9 (patch)
tree9bf0ea17ca09ee83462665bea96f9afe1a2cbab4 /fxjs
parent3d8131535e6b127c7ededdbd2e76662688997272 (diff)
downloadpdfium-d52a0afaa3e4374dee469e41db4389bf9c61c4a9.tar.xz
Use the length of calculated string instead of source
In this function a string is converted to UTF8, if there are non-printing characters in the original string, the generated string will be shorter. Thus using the original string length for iteration range will cause an OOB read. BUG=chromium:854623 Change-Id: I338005476c3de529709f3eae6892d27a6c7f2263 Reviewed-on: https://pdfium-review.googlesource.com/35810 Commit-Queue: Ryan Harrison <rharrison@chromium.org> Reviewed-by: Tom Sepez <tsepez@chromium.org>
Diffstat (limited to 'fxjs')
-rw-r--r--fxjs/cfxjse_formcalc_context.cpp7
-rw-r--r--fxjs/cfxjse_formcalc_context_embeddertest.cpp10
2 files changed, 11 insertions, 6 deletions
diff --git a/fxjs/cfxjse_formcalc_context.cpp b/fxjs/cfxjse_formcalc_context.cpp
index 3ed8a78da3..15401a010e 100644
--- a/fxjs/cfxjse_formcalc_context.cpp
+++ b/fxjs/cfxjse_formcalc_context.cpp
@@ -3891,17 +3891,12 @@ void CFXJSE_FormCalcContext::Lower(CFXJSE_Value* pThis,
CFX_WideTextBuf lowStringBuf;
ByteString argString = ValueToUTF8String(argOne.get());
WideString wsArgString = WideString::FromUTF8(argString.AsStringView());
- const wchar_t* pData = wsArgString.c_str();
- size_t i = 0;
- while (i < argString.GetLength()) {
- int32_t ch = pData[i];
+ for (auto ch : wsArgString) {
if ((ch >= 0x41 && ch <= 0x5A) || (ch >= 0xC0 && ch <= 0xDE))
ch += 32;
else if (ch == 0x100 || ch == 0x102 || ch == 0x104)
ch += 1;
-
lowStringBuf.AppendChar(ch);
- ++i;
}
lowStringBuf.AppendChar(0);
diff --git a/fxjs/cfxjse_formcalc_context_embeddertest.cpp b/fxjs/cfxjse_formcalc_context_embeddertest.cpp
index 58cb34b6d9..22e6b25afc 100644
--- a/fxjs/cfxjse_formcalc_context_embeddertest.cpp
+++ b/fxjs/cfxjse_formcalc_context_embeddertest.cpp
@@ -1176,6 +1176,16 @@ TEST_F(CFXJSE_FormCalcContextEmbedderTest, Lower) {
}
}
+// This is testing for an OOB read, so will likely only fail under ASAN.
+TEST_F(CFXJSE_FormCalcContextEmbedderTest, bug_854623) {
+ ASSERT_TRUE(OpenDocument("simple_xfa.pdf"));
+
+ const uint8_t test_string[] = {
+ 0x4c, 0x6f, 0x77, 0x65, 0x72, 0x28, 0x22, 0xc3,
+ 0x85, 0xc3, 0x85, 0xc3, 0x85, 0x22, 0x29}; // Lower("ÅÅÅ")
+ Execute(ByteString(test_string, sizeof(test_string)).AsStringView());
+}
+
TEST_F(CFXJSE_FormCalcContextEmbedderTest, Ltrim) {
ASSERT_TRUE(OpenDocument("simple_xfa.pdf"));