Harden the dbstat extension against corrupt database files.

FossilOrigin-Name: a0d47f25ae7bdf98f5b853f23776b3bf86bea7c0dda386664c1e3b1c363c518f

diff --git a/manifest b/manifest
index ca47a751758398078a2e693632414a98300c6847..aaed9b62d8591bae5c9bf35f13831a8dc95e744a 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Improvements\sto\sthe\sdbfuzz2.c\stest\smodule.
-D 2018-10-27T21:06:44.652
+C Harden\sthe\sdbstat\sextension\sagainst\scorrupt\sdatabase\sfiles.
+D 2018-10-29T16:07:10.322
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in 15344f4e44dfd9ffb04e9867bdd352a8a5a86211b8919a6ca724e7063694320b
@@ -454,7 +454,7 @@ F src/complete.c a3634ab1e687055cd002e11b8f43eb75c17da23e
 F src/ctime.c 56e2f32d2e5491c152352bd53cffc9979ee1e1b70df39ec97a90920ae420a950
 F src/date.c ebe1dc7c8a347117bb02570f1a931c62dd78f4a2b1b516f4837d45b7d6426957
 F src/dbpage.c 4aa7f26198934dbd002e69418220eae3dbc71b010bbac32bd78faf86b52ce6c3
-F src/dbstat.c edabb82611143727511a45ca0859b8cd037851ebe756ae3db289859dd18b6f91
+F src/dbstat.c 5f96184b8a751b7c92b959b55679f56e409c3b3bbe98eaf5e43189c16d4df082
 F src/delete.c 107e28d3ef8bd72fd11953374ca9107cd74e8b09c3ded076a6048742d26ce7d2
 F src/expr.c 5cee8fb79b1952689af80ed71ed16ad295f29d85de30c7592993b05cf1ec1e06
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
@@ -1774,7 +1774,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P a4a083ed8cdb106af661d2ee0203e21c576f5c2304419ce603826e4f2851c2e0
-R e5a9cd9771ffc88fd093fdbd062e0c2a
+P d60eff493b875366981c5a25000bb65cde9f6e628192914910790acc562c17b9
+R 668f948a6c21a9c15cb9b96a8664b9e2
 U drh
-Z 7b11fae1033935d453c9b6c66817005d
+Z 0ebd96da0851d12eb56b4ff281cd01aa

diff --git a/manifest.uuid b/manifest.uuid
index 4ba4dbd6aef29262d36b7e161756837f58ce469c..27cd6745a31d5ba897843d1d6069350fb168e2f5 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-d60eff493b875366981c5a25000bb65cde9f6e628192914910790acc562c17b9
\ No newline at end of file
+a0d47f25ae7bdf98f5b853f23776b3bf86bea7c0dda386664c1e3b1c363c518f
\ No newline at end of file

diff --git a/src/dbstat.c b/src/dbstat.c
index 0f1fd0a70c95d3f433179c8a24e6de054aaafba0..0eb70d6ce8a75860f18475d5d0ccbb9e87eb4760 100644 (file)
--- a/src/dbstat.c
+++ b/src/dbstat.c
@@ -324,22 +324,33 @@ static int statDecodePage(Btree *pBt, StatPage *p){
   u8 *aHdr = &aData[p->iPgno==1 ? 100 : 0];
 
   p->flags = aHdr[0];
+  if( p->flags==0x0A || p->flags==0x0D ){
+    isLeaf = 1;
+    nHdr = 8;
+  }else if( p->flags==0x05 || p->flags==0x02 ){
+    isLeaf = 0;
+    nHdr = 12;
+  }else{
+    goto statPageIsCorrupt;
+  }
+  if( p->iPgno==1 ) nHdr += 100;
   p->nCell = get2byte(&aHdr[3]);
   p->nMxPayload = 0;
-
-  isLeaf = (p->flags==0x0A || p->flags==0x0D);
-  nHdr = 12 - isLeaf*4 + (p->iPgno==1)*100;
+  szPage = sqlite3BtreeGetPageSize(pBt);
 
   nUnused = get2byte(&aHdr[5]) - nHdr - 2*p->nCell;
   nUnused += (int)aHdr[7];
   iOff = get2byte(&aHdr[1]);
   while( iOff ){
+    int iNext;
+    if( iOff>=szPage ) goto statPageIsCorrupt;
     nUnused += get2byte(&aData[iOff+2]);
-    iOff = get2byte(&aData[iOff]);
+    iNext = get2byte(&aData[iOff]);
+    if( iNext<iOff+4 && iNext>0 ) goto statPageIsCorrupt;
+    iOff = iNext;
   }
   p->nUnused = nUnused;
   p->iRightChildPg = isLeaf ? 0 : sqlite3Get4byte(&aHdr[8]);
-  szPage = sqlite3BtreeGetPageSize(pBt);
 
   if( p->nCell ){
     int i;                        /* Used to iterate through cells */
@@ -356,6 +367,7 @@ static int statDecodePage(Btree *pBt, StatPage *p){
       StatCell *pCell = &p->aCell[i];
 
       iOff = get2byte(&aData[nHdr+i*2]);
+      if( iOff<nHdr || iOff>=szPage ) goto statPageIsCorrupt;
       if( !isLeaf ){
         pCell->iChildPg = sqlite3Get4byte(&aData[iOff]);
         iOff += 4;
@@ -372,8 +384,8 @@ static int statDecodePage(Btree *pBt, StatPage *p){
         }
         if( nPayload>(u32)p->nMxPayload ) p->nMxPayload = nPayload;
         getLocalPayload(nUsable, p->flags, nPayload, &nLocal);
+        if( nLocal<0 ) goto statPageIsCorrupt;
         pCell->nLocal = nLocal;
-        assert( nLocal>=0 );
         assert( nPayload>=(u32)nLocal );
         assert( nLocal<=(nUsable-35) );
         if( nPayload>(u32)nLocal ){
@@ -402,6 +414,11 @@ static int statDecodePage(Btree *pBt, StatPage *p){
   }
 
   return SQLITE_OK;
+
+statPageIsCorrupt:
+  p->flags = 0;
+  p->nCell = 0;
+  return SQLITE_OK;
 }
 
 /*