Ensure that UTF16 strings are properly zero-terminated before returning them

in an sqlite3_value_text16() request, even if the string is invalid UTF16
because it was formed from an arbitrary and/or odd-length BLOB.

FossilOrigin-Name: 3a16ddf91f0c9c516a7fc2a9d4a4f69a8326f9b8ea66421e9ef1a2d663687b70

diff --git a/manifest b/manifest
index e6797fc705b5e73ad7d653d9f34ab343ccab0ce7..6b54f864dea30655c1d4e12cac56c99e48448623 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sa\smemory-leak/segfault\scaused\sby\susing\sOP_OpenDup\sand\sOP_OpenEphemeral\son\sthe\ssame\sVM\scursor.
-D 2019-05-03T18:50:24.588
+C Ensure\sthat\sUTF16\sstrings\sare\sproperly\szero-terminated\sbefore\sreturning\sthem\nin\san\ssqlite3_value_text16()\srequest,\seven\sif\sthe\sstring\sis\sinvalid\sUTF16\nbecause\sit\swas\sformed\sfrom\san\sarbitrary\sand/or\sodd-length\sBLOB.
+D 2019-05-03T19:34:41.227
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -597,7 +597,7 @@ F src/vdbeInt.h 3ba14553508d66f58753952d6dd287dce4ec735de02c6440858b4891aed51c17
 F src/vdbeapi.c 5ef992332225d8b6151137fcaf33b4ba4d38db7e7c51f871d2e9ecb960f3709a
 F src/vdbeaux.c f873b5c2efcf8a4d6ecfc5b1a5b06fd810419198f3bd882175d371cc03801873
 F src/vdbeblob.c f5c70f973ea3a9e915d1693278a5f890dc78594300cf4d54e64f2b0917c94191
-F src/vdbemem.c df36fd36c7585e42869f3a44f5da5dc70e13306bc97ba52eebe069e174ba55db
+F src/vdbemem.c 42a33c8f00728fcf141b05f9c4d1bc3a2d34ebc4427b8631898e31fc22ea944d
 F src/vdbesort.c 66592d478dbb46f19aed0b42222325eadb84deb40a90eebe25c6e7c1d8468f47
 F src/vdbetrace.c 79d6dbbc479267b255a7de8080eee6e729928a0ef93ed9b0bfa5618875b48392
 F src/vtab.c 1fa256c6ddad7a81e2a4dc080d015d4b0a7135767717d311298e47f6fca64bb3
@@ -1822,7 +1822,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 74ef97bf51dd531a277cf22fa4d42043d93799d5a5bd550812648834460fe0b7
-R 5407b1be905c1bcf46d2ef60d3252201
-U dan
-Z efe7ecc358ec0708b5835450f237d48e
+P a9b90aa12eecdd9f2a8b2d23da8b7cac43d8b1789f5cefa3f4e939d9f2b59269
+R 0f91a6c43eba1f33d4776f7747589015
+U drh
+Z 872a39f55a8963133e9f411eb3938cfd

diff --git a/manifest.uuid b/manifest.uuid
index 99fae280f7e6c864bae550357b67c8dc5148f76a..450783c9a4d889e6a43b32d15d57155c309bae0d 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-a9b90aa12eecdd9f2a8b2d23da8b7cac43d8b1789f5cefa3f4e939d9f2b59269
\ No newline at end of file
+3a16ddf91f0c9c516a7fc2a9d4a4f69a8326f9b8ea66421e9ef1a2d663687b70
\ No newline at end of file

diff --git a/src/vdbemem.c b/src/vdbemem.c
index 82f7f3e1026a324325a3290c000394894be54733..96edebcdefcbbe2b89f972017dc6e5c51e72444a 100644 (file)
--- a/src/vdbemem.c
+++ b/src/vdbemem.c
@@ -270,13 +270,19 @@ int sqlite3VdbeMemClearAndResize(Mem *pMem, int szNew){
 /*
 ** It is already known that pMem contains an unterminated string.
 ** Add the zero terminator.
+**
+** Three bytes of zero are added.  In this way, there is guaranteed
+** to be a double-zero byte at an even byte boundary in order to
+** terminate a UTF16 string, even if the initial size of the buffer
+** is an odd number of bytes.
 */
 static SQLITE_NOINLINE int vdbeMemAddTerminator(Mem *pMem){
-  if( sqlite3VdbeMemGrow(pMem, pMem->n+2, 1) ){
+  if( sqlite3VdbeMemGrow(pMem, pMem->n+3, 1) ){
     return SQLITE_NOMEM_BKPT;
   }
   pMem->z[pMem->n] = 0;
   pMem->z[pMem->n+1] = 0;
+  pMem->z[pMem->n+2] = 0;
   pMem->flags |= MEM_Term;
   return SQLITE_OK;
 }
@@ -350,9 +356,9 @@ int sqlite3VdbeMemNulTerminate(Mem *pMem){
 }
 
 /*
-** Add MEM_Str to the set of representations for the given Mem.  Numbers
-** are converted using sqlite3_snprintf().  Converting a BLOB to a string
-** is a no-op.
+** Add MEM_Str to the set of representations for the given Mem.  This
+** routine is only called if pMem is a number of some kind, not a NULL
+** or a BLOB.
 **
 ** Existing representations MEM_Int and MEM_Real are invalidated if
 ** bForce is true but are retained if bForce is false.