Guard against attacks from deliberately corrupted database files. (CVS 6021)

FossilOrigin-Name: da2ec96422b1f9de2e47d3b8c19ed20579742a9b

manifest

@@ -1,5 +1,5 @@
-C Increase\sthe\sversion\snumber\sto\s3.6.7.\s(CVS\s6020)
-D 2008-12-11T13:08:16
+C Guard\sagainst\sattacks\sfrom\sdeliberately\scorrupted\sdatabase\sfiles.\s(CVS\s6021)
+D 2008-12-11T16:17:04
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in f7e4c81c347b04f7b0f1c1b081a168645d7b8af7
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -194,11 +194,11 @@ F src/update.c 080889d241e4dcd1c545c8051eb6de86f4939295
 F src/utf.c 1da9c832dba0fa8f865b5b902d93f420a1ee4245
 F src/util.c ea62608f66f33a7e8322de83024ae37c415c0c7f
 F src/vacuum.c 383d6297bddc011ab04a9eed110db6eaf523e8e9
-F src/vdbe.c 3a184e2654f6018b86827e1fa8ec414f9e4daa65
+F src/vdbe.c 46eed1fc5f24500d551c6aac960f812c6145dcee
 F src/vdbe.h 03516f28bf5aca00a53c4dccd6c313f96adb94f6
 F src/vdbeInt.h e6e80a99ce634983b7cc2498843b4d2e5540900a
 F src/vdbeapi.c 85c33cfbfa56249cbe627831610afafba754477d
-F src/vdbeaux.c 5356c9bbac2fb0cb75b816de1d5963b26547f656
+F src/vdbeaux.c d3a785736a7dc46a3950d393008f1ee939198a48
 F src/vdbeblob.c b0dcebfafedcf9c0addc7901ad98f6f986c08935
 F src/vdbemem.c f9c859ac17e2e05a0f249868ce4f191f69edd31d
 F src/vtab.c e39e011d7443a8d574b1b9cde207a35522e6df43
@@ -664,7 +664,7 @@ F tool/speedtest16.c c8a9c793df96db7e4933f0852abb7a03d48f2e81
 F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
-P 0d316160fc9e24262457d330abee40f447ff909e
-R d4b82cc49600a0df1f6c3ae2d356b4a1
+P 7c367515f86c36b7ec8603754b20f1c7c4a0690a
+R 444a7244e9f7d54c88f06e95ece4e75e
 U drh
-Z c2052c4867eec9cd027c15a6112f4f1d
+Z 5d08690a9b2d2b8626ebdbffda6c718a

manifest.uuid

@@ -1 +1 @@
-7c367515f86c36b7ec8603754b20f1c7c4a0690a
+da2ec96422b1f9de2e47d3b8c19ed20579742a9b

src/vdbe.c

@@ -43,7 +43,7 @@
 ** in this file for details.  If in doubt, do not deviate from existing
 ** commenting and indentation practices when changing or adding code.
 **
-** $Id: vdbe.c,v 1.798 2008/12/11 13:05:00 drh Exp $
+** $Id: vdbe.c,v 1.799 2008/12/11 16:17:04 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -4100,7 +4100,7 @@ case OP_Clear: {
 */
 case OP_CreateIndex:            /* out2-prerelease */
 case OP_CreateTable: {          /* out2-prerelease */
-  int pgno;
+  int pgno = 0;
   int flags;
   Db *pDb;
   assert( pOp->p1>=0 && pOp->p1<db->nDb );
@@ -4114,10 +4114,8 @@ case OP_CreateTable: {          /* out2-prerelease */
     flags = BTREE_ZERODATA;
   }
   rc = sqlite3BtreeCreateTable(pDb->pBt, &pgno, flags);
-  if( rc==SQLITE_OK ){
-    pOut->u.i = pgno;
-    MemSetTypeFlag(pOut, MEM_Int);
-  }
+  pOut->u.i = pgno;
+  MemSetTypeFlag(pOut, MEM_Int);
   break;
 }
 

src/vdbeaux.c

@@ -14,7 +14,7 @@
 ** to version 2.8.7, all this code was combined into the vdbe.c source file.
 ** But that file was getting too big so this subroutines were split out.
 **
-** $Id: vdbeaux.c,v 1.426 2008/12/10 19:26:24 drh Exp $
+** $Id: vdbeaux.c,v 1.427 2008/12/11 16:17:04 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -2384,6 +2384,9 @@ int sqlite3VdbeRecordCompare(
 ** pCur points at an index entry created using the OP_MakeRecord opcode.
 ** Read the rowid (the last field in the record) and store it in *rowid.
 ** Return SQLITE_OK if everything works, or an error code otherwise.
+**
+** pCur might be pointing to text obtained from a corrupt database file.
+** So the content cannot be trusted.  Do appropriate checks on the content.
 */
 int sqlite3VdbeIdxRowid(BtCursor *pCur, i64 *rowid){
   i64 nCellKey = 0;
@@ -2393,10 +2396,14 @@ int sqlite3VdbeIdxRowid(BtCursor *pCur, i64 *rowid){
   u32 lenRowid;     /* Size of the rowid */
   Mem m, v;
 
+  /* Get the size of the index entry.  Only indices entries of less
+  ** than 2GiB are support - anything large must be database corruption */
   sqlite3BtreeKeySize(pCur, &nCellKey);
-  if( nCellKey<=0 || nCellKey>0x7fffffff ){
+  if( unlikely(nCellKey<=0 || nCellKey>0x7fffffff) ){
     return SQLITE_CORRUPT_BKPT;
   }
+
+  /* Read in the complete content of the index entry */
   m.flags = 0;
   m.db = 0;
   m.zMalloc = 0;
@@ -2404,13 +2411,47 @@ int sqlite3VdbeIdxRowid(BtCursor *pCur, i64 *rowid){
   if( rc ){
     return rc;
   }
+
+  /* The index entry must begin with a header size */
   (void)getVarint32((u8*)m.z, szHdr);
+  testcase( szHdr==2 );
+  testcase( szHdr==m.n );
+  if( unlikely(szHdr<2 || szHdr>m.n) ){
+    goto idx_rowid_corruption;
+  }
+
+  /* The last field of the index should be an integer - the ROWID.
+  ** Verify that the last entry really is an integer. */
   (void)getVarint32((u8*)&m.z[szHdr-1], typeRowid);
+  testcase( typeRowid==1 );
+  testcase( typeRowid==2 );
+  testcase( typeRowid==3 );
+  testcase( typeRowid==4 );
+  testcase( typeRowid==5 );
+  testcase( typeRowid==6 );
+  testcase( typeRowid==8 );
+  testcase( typeRowid==9 );
+  if( unlikely(typeRowid<1 || typeRowid>9 || typeRowid==7) ){
+    goto idx_rowid_corruption;
+  }
   lenRowid = sqlite3VdbeSerialTypeLen(typeRowid);
+  testcase( m.n-lenRowid==szHdr );
+  if( unlikely(m.n-lenRowid<szHdr) ){
+    goto idx_rowid_corruption;
+  }
+
+  /* Fetch the integer off the end of the index record */
   sqlite3VdbeSerialGet((u8*)&m.z[m.n-lenRowid], typeRowid, &v);
   *rowid = v.u.i;
   sqlite3VdbeMemRelease(&m);
   return SQLITE_OK;
+
+  /* Jump here if database corruption is detected after m has been
+  ** allocated.  Free the m object and return SQLITE_CORRUPT. */
+idx_rowid_corruption:
+  testcase( m.zMalloc!=0 );
+  sqlite3VdbeMemRelease(&m);
+  return SQLITE_CORRUPT_BKPT;
 }
 
 /*