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Check-in [395599116d]
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Overview
Comment:Fix possible integer overflow while running PRAGMA integrity_check on a database file with a badly corrupted freelist.
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Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA3-256: 395599116d801324f0763e59bc5e2fc8622aa5b7572e0c1c9a982efbb3cc8280
User & Date: drh 2018-12-14 17:57:01.278
Context
2018-12-14
18:11
Fix harmless compiler warnings. (check-in: 27221c6990 user: drh tags: trunk)
17:57
Fix possible integer overflow while running PRAGMA integrity_check on a database file with a badly corrupted freelist. (check-in: 395599116d user: drh tags: trunk)
16:20
Back out the expansion of the temporary buffer size from [32754ca6f86da816] and replace it with an explicit test for buffer overreads. (check-in: 8ba3d9f380 user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/btree.c.
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    N--;
    if( sqlite3PagerGet(pCheck->pPager, (Pgno)iPage, &pOvflPage, 0) ){
      checkAppendMsg(pCheck, "failed to get page %d", iPage);
      break;
    }
    pOvflData = (unsigned char *)sqlite3PagerGetData(pOvflPage);
    if( isFreeList ){
      int n = get4byte(&pOvflData[4]);
#ifndef SQLITE_OMIT_AUTOVACUUM
      if( pCheck->pBt->autoVacuum ){
        checkPtrmap(pCheck, iPage, PTRMAP_FREEPAGE, 0);
      }
#endif
      if( n>(int)pCheck->pBt->usableSize/4-2 ){
        checkAppendMsg(pCheck,
           "freelist leaf count too big on page %d", iPage);
        N--;
      }else{
        for(i=0; i<n; i++){
          Pgno iFreePage = get4byte(&pOvflData[8+i*4]);
#ifndef SQLITE_OMIT_AUTOVACUUM
          if( pCheck->pBt->autoVacuum ){
            checkPtrmap(pCheck, iFreePage, PTRMAP_FREEPAGE, 0);
          }
#endif
          checkRef(pCheck, iFreePage);








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9410
9411
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9421
9422
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9424
9425
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9427
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    N--;
    if( sqlite3PagerGet(pCheck->pPager, (Pgno)iPage, &pOvflPage, 0) ){
      checkAppendMsg(pCheck, "failed to get page %d", iPage);
      break;
    }
    pOvflData = (unsigned char *)sqlite3PagerGetData(pOvflPage);
    if( isFreeList ){
      u32 n = (u32)get4byte(&pOvflData[4]);
#ifndef SQLITE_OMIT_AUTOVACUUM
      if( pCheck->pBt->autoVacuum ){
        checkPtrmap(pCheck, iPage, PTRMAP_FREEPAGE, 0);
      }
#endif
      if( n>pCheck->pBt->usableSize/4-2 ){
        checkAppendMsg(pCheck,
           "freelist leaf count too big on page %d", iPage);
        N--;
      }else{
        for(i=0; i<(int)n; i++){
          Pgno iFreePage = get4byte(&pOvflData[8+i*4]);
#ifndef SQLITE_OMIT_AUTOVACUUM
          if( pCheck->pBt->autoVacuum ){
            checkPtrmap(pCheck, iFreePage, PTRMAP_FREEPAGE, 0);
          }
#endif
          checkRef(pCheck, iFreePage);
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