From 0d13e8740021aeeb849662f03f49720287cabe0c Mon Sep 17 00:00:00 2001
From: Scott Hess <shess@chromium.org>
Date: Fri, 26 Feb 2016 10:49:33 -0800
Subject: [PATCH 13/13] [backport] Fix buffer overrun in ICU extension's
 casemap functions.

Original Chromium CL at https://codereview.chromium.org/1704103002

"Fix sqlite3's handling of casemapping result 3 times as long as input"

SQLite interpretation at http://www.sqlite.org/src/info/b8dc1b9f5d413000

"Fix a potential buffer overflow in the ICU upper() function."

BUG=586079
---
 third_party/sqlite/src/ext/icu/icu.c | 48 +++++++++++++++++++++---------------
 third_party/sqlite/src/test/icu.test |  9 +++++++
 2 files changed, 37 insertions(+), 20 deletions(-)

diff --git a/third_party/sqlite/src/ext/icu/icu.c b/third_party/sqlite/src/ext/icu/icu.c
index 5654366..263cd98 100644
--- a/third_party/sqlite/src/ext/icu/icu.c
+++ b/third_party/sqlite/src/ext/icu/icu.c
@@ -355,11 +355,11 @@ static void icuRegexpFunc(sqlite3_context *p, int nArg, sqlite3_value **apArg){
 */
 static void icuCaseFunc16(sqlite3_context *p, int nArg, sqlite3_value **apArg){
   const UChar *zInput;
-  UChar *zOutput;
+  UChar *zOutput = 0;
   int nInput;
-  int nOutput;
-
-  UErrorCode status = U_ZERO_ERROR;
+  int nOut;
+  int cnt;
+  UErrorCode status;
   const char *zLocale = 0;
 
   assert(nArg==1 || nArg==2);
@@ -371,26 +371,34 @@ static void icuCaseFunc16(sqlite3_context *p, int nArg, sqlite3_value **apArg){
   if( !zInput ){
     return;
   }
-  nInput = sqlite3_value_bytes16(apArg[0]);
-
-  nOutput = nInput * 2 + 2;
-  zOutput = sqlite3_malloc(nOutput);
-  if( !zOutput ){
+  nOut = nInput = sqlite3_value_bytes16(apArg[0]);
+  if( nOut==0 ){
+    sqlite3_result_text16(p, "", 0, SQLITE_STATIC);
     return;
   }
 
-  if( sqlite3_user_data(p) ){
-    u_strToUpper(zOutput, nOutput/2, zInput, nInput/2, zLocale, &status);
-  }else{
-    u_strToLower(zOutput, nOutput/2, zInput, nInput/2, zLocale, &status);
-  }
-
-  if( !U_SUCCESS(status) ){
-    icuFunctionError(p, "u_strToLower()/u_strToUpper", status);
-    return;
+  for(cnt=0; cnt<2; cnt++){
+    UChar *zNew = sqlite3_realloc(zOutput, nOut);
+    if( zNew==0 ){
+      sqlite3_free(zOutput);
+      sqlite3_result_error_nomem(p);
+      return;
+    }
+    zOutput = zNew;
+    status = U_ZERO_ERROR;
+    if( sqlite3_user_data(p) ){
+      nOut = 2*u_strToUpper(zOutput,nOut/2,zInput,nInput/2,zLocale,&status);
+    }else{
+      nOut = 2*u_strToLower(zOutput,nOut/2,zInput,nInput/2,zLocale,&status);
+    }
+    if( !U_SUCCESS(status) ){
+      if( status==U_BUFFER_OVERFLOW_ERROR ) continue;
+      icuFunctionError(p,
+          sqlite3_user_data(p) ? "u_strToUpper()" : "u_strToLower", status);
+      return;
+    }
   }
-
-  sqlite3_result_text16(p, zOutput, -1, xFree);
+  sqlite3_result_text16(p, zOutput, nOut, xFree);
 }
 
 /*
diff --git a/third_party/sqlite/src/test/icu.test b/third_party/sqlite/src/test/icu.test
index 73cb9b9..743bcfa 100644
--- a/third_party/sqlite/src/test/icu.test
+++ b/third_party/sqlite/src/test/icu.test
@@ -72,6 +72,10 @@ test_expr icu-2.6 {i1=$::OGRAVE} {upper(i1)}     $::OGRAVE
 test_expr icu-2.7 {i1=$::szlig} {upper(i1)}      "SS"
 test_expr icu-2.8 {i1='SS'} {lower(i1)}          "ss"
 
+do_execsql_test icu-2.9 {
+  SELECT upper(char(0xfb04,0xfb04,0xfb04,0xfb04));
+} {FFLFFLFFLFFL}
+
 # In turkish (locale="tr_TR"), the lower case version of I
 # is "small dotless i" (code point 0x131 (decimal 305)).
 #
@@ -133,4 +137,9 @@ do_catchsql_test icu-5.4 {
 do_catchsql_test icu-5.4 { SELECT 'abc' REGEXP }    {1 {near " ": syntax error}}
 do_catchsql_test icu-5.5 { SELECT 'abc' REGEXP, 1 } {1 {near ",": syntax error}}
 
+
+do_malloc_test icu-6.10 -sqlbody {
+  SELECT upper(char(0xfb04,0xdf,0xfb04,0xe8,0xfb04));
+}
+
 finish_test
-- 
2.7.0