Fix some cases in the fts5 code where a corrupt database could cause a buffer overread.

FossilOrigin-Name: 360c57bbb8bad6cc84af140f61e0282fa06462b4

ext/fts5/fts5_index.c

@@ -1847,7 +1847,7 @@ static void fts5SegIterNext(
           fts5SegIterNextPage(p, pIter);
           pLeaf = pIter->pLeaf;
           if( pLeaf==0 ) break;
-          if( (iOff = fts5GetU16(&pLeaf->p[0])) ){
+          if( (iOff = fts5GetU16(&pLeaf->p[0])) && iOff<pLeaf->n ){
             iOff += sqlite3Fts5GetVarint(&pLeaf->p[iOff], (u64*)&pIter->iRowid);
             pIter->iLeafOffset = iOff;
           }
@@ -1855,6 +1855,10 @@ static void fts5SegIterNext(
             pIter->iLeafOffset = iOff;
             bNewTerm = 1;
           }
+          if( iOff>=pLeaf->n ){
+            p->rc = FTS5_CORRUPT;
+            return;
+          }
         }
       }
 
@@ -2025,6 +2029,7 @@ static void fts5SegIterSeekInit(
   int h;
   int bGe = (flags & FTS5INDEX_QUERY_SCAN);
   int bDlidx = 0;                 /* True if there is a doclist-index */
+  Fts5Data *pLeaf;
 
   assert( bGe==0 || (flags & FTS5INDEX_QUERY_DESC)==0 );
   assert( pTerm && nTerm );
@@ -2063,21 +2068,25 @@ static void fts5SegIterSeekInit(
   pIter->iLeafPgno = iPg - 1;
   fts5SegIterNextPage(p, pIter);
 
-  if( pIter->pLeaf ){
+  if( (pLeaf = pIter->pLeaf) ){
     int res;
-    pIter->iLeafOffset = fts5GetU16(&pIter->pLeaf->p[2]);
-    fts5SegIterLoadTerm(p, pIter, 0);
-    fts5SegIterLoadNPos(p, pIter);
-    do {
-      res = fts5BufferCompareBlob(&pIter->term, pTerm, nTerm);
-      if( res>=0 ) break;
-      fts5SegIterNext(p, pIter, 0);
-    }while( pIter->pLeaf && p->rc==SQLITE_OK );
+    pIter->iLeafOffset = fts5GetU16(&pLeaf->p[2]);
+    if( pIter->iLeafOffset<4 || pIter->iLeafOffset>=pLeaf->n ){
+      p->rc = FTS5_CORRUPT;
+    }else{
+      fts5SegIterLoadTerm(p, pIter, 0);
+      fts5SegIterLoadNPos(p, pIter);
+      do {
+        res = fts5BufferCompareBlob(&pIter->term, pTerm, nTerm);
+        if( res>=0 ) break;
+        fts5SegIterNext(p, pIter, 0);
+      }while( pIter->pLeaf && p->rc==SQLITE_OK );
 
-    if( bGe==0 && res ){
-      /* Set iterator to point to EOF */
-      fts5DataRelease(pIter->pLeaf);
-      pIter->pLeaf = 0;
+      if( bGe==0 && res ){
+        /* Set iterator to point to EOF */
+        fts5DataRelease(pIter->pLeaf);
+        pIter->pLeaf = 0;
+      }
     }
   }
 
@@ -2525,7 +2534,7 @@ static void fts5MultiIterNew(
   int nSegment,                   /* Number of segments to merge (iLevel>=0) */
   Fts5MultiSegIter **ppOut        /* New object */
 ){
-  int nSeg;                       /* Number of segment-iters in use */
+  int nSeg = 0;                   /* Number of segment-iters in use */
   int iIter = 0;                  /* */
   int iSeg;                       /* Used to iterate through segments */
   Fts5StructureLevel *pLvl;
@@ -4928,8 +4937,12 @@ static void fts5IndexIntegrityCheckSegment(
         if( pLeaf ){
           i64 iRowid;
           int iRowidOff = fts5GetU16(&pLeaf->p[0]);
-          fts5GetVarint(&pLeaf->p[iRowidOff], (u64*)&iRowid);
-          if( iRowid!=fts5DlidxIterRowid(pDlidx) ) p->rc = FTS5_CORRUPT;
+          if( iRowidOff>=pLeaf->n ){
+            p->rc = FTS5_CORRUPT;
+          }else{
+            fts5GetVarint(&pLeaf->p[iRowidOff], (u64*)&iRowid);
+            if( iRowid!=fts5DlidxIterRowid(pDlidx) ) p->rc = FTS5_CORRUPT;
+          }
           fts5DataRelease(pLeaf);
         }
       }

manifest

@@ -1,5 +1,5 @@
-C Merge\schanges\sto\sget\sFTS5\sworking\swith\sMSVC.
-D 2015-06-26T17:10:12.989
+C Fix\ssome\scases\sin\sthe\sfts5\scode\swhere\sa\scorrupt\sdatabase\scould\scause\sa\sbuffer\soverread.
+D 2015-06-26T18:50:29.818
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 285a0a234ed7610d431d91671c136098c2bd86a9
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -112,7 +112,7 @@ F ext/fts5/fts5_buffer.c 7428b0bcb257641cbecc3bacce7f40686cf99f36
 F ext/fts5/fts5_config.c d40da53f5e94214c553b2af3d6fd9aebac5f3f05
 F ext/fts5/fts5_expr.c 3386ab0a71dbab7e1259c3b16d6113c97d14123e
 F ext/fts5/fts5_hash.c c1cfdb2cae0fad00b06fae38a40eaf9261563ccc
-F ext/fts5/fts5_index.c 0c5a5218eb9fddd65c7d5bbad72c383d102c9648
+F ext/fts5/fts5_index.c ad32235180757f182050b8d24c9dbe61056385d2
 F ext/fts5/fts5_main.c c5b2a219d65967c07fd1bc8fd45206863a2fe360
 F ext/fts5/fts5_storage.c 3e672a0d35f63979556903861b324e7b8932cecc
 F ext/fts5/fts5_tcl.c b82f13f73a30f0959f539743f8818bece994a970
@@ -1364,8 +1364,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 48bd54594752d5be3337f12c72f28d2080cb630b
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P c91a93b343b4d3b1a19afdb5d23d1c508f9779d2 bfcd16089cf8c65130c011a9718bf7812685c841
-R 297861c6724b6a9194bdf2ab25858763
-T +closed bfcd16089cf8c65130c011a9718bf7812685c841
-U mistachkin
-Z d2f82b98bab3ebc4b4555fb7502228b7
+P 954231d29d60460d423ecb132bbfb725b0ea375a
+R f24cf4dc2b8231a9cc4f2e0f89642df3
+U dan
+Z eeb5dd5cce2b08a289c0b394982d9461

manifest.uuid

@@ -1 +1 @@
-954231d29d60460d423ecb132bbfb725b0ea375a
+360c57bbb8bad6cc84af140f61e0282fa06462b4