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Overview
Comment: | Harden the dbstat extension against corrupt database files. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA3-256: |
a0d47f25ae7bdf98f5b853f23776b3bf |
User & Date: | drh 2018-10-29 16:07:10.322 |
Context
2018-10-29
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17:08 | In the sessions module, avoid collecting rebase data if the user has not requested it. (check-in: de72a773dd user: dan tags: trunk) | |
16:07 | Harden the dbstat extension against corrupt database files. (check-in: a0d47f25ae user: drh tags: trunk) | |
2018-10-27
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21:06 | Improvements to the dbfuzz2.c test module. (check-in: d60eff493b user: drh tags: trunk) | |
Changes
Changes to src/dbstat.c.
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320 321 322 323 324 325 326 327 328 | int isLeaf; int szPage; u8 *aData = sqlite3PagerGetData(p->pPg); u8 *aHdr = &aData[p->iPgno==1 ? 100 : 0]; p->flags = aHdr[0]; p->nCell = get2byte(&aHdr[3]); p->nMxPayload = 0; | > > > > > > > > > > | < < > > | > > < > > < | 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 | int isLeaf; int szPage; u8 *aData = sqlite3PagerGetData(p->pPg); 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; 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]); iNext = get2byte(&aData[iOff]); if( iNext<iOff+4 && iNext>0 ) goto statPageIsCorrupt; iOff = iNext; } p->nUnused = nUnused; p->iRightChildPg = isLeaf ? 0 : sqlite3Get4byte(&aHdr[8]); if( p->nCell ){ int i; /* Used to iterate through cells */ int nUsable; /* Usable bytes per page */ sqlite3BtreeEnter(pBt); nUsable = szPage - sqlite3BtreeGetReserveNoMutex(pBt); sqlite3BtreeLeave(pBt); p->aCell = sqlite3_malloc64((p->nCell+1) * sizeof(StatCell)); if( p->aCell==0 ) return SQLITE_NOMEM_BKPT; memset(p->aCell, 0, (p->nCell+1) * sizeof(StatCell)); for(i=0; i<p->nCell; i++){ 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; } if( p->flags==0x05 ){ /* A table interior node. nPayload==0. */ }else{ u32 nPayload; /* Bytes of payload total (local+overflow) */ int nLocal; /* Bytes of payload stored locally */ iOff += getVarint32(&aData[iOff], nPayload); if( p->flags==0x0D ){ u64 dummy; iOff += sqlite3GetVarint(&aData[iOff], &dummy); } if( nPayload>(u32)p->nMxPayload ) p->nMxPayload = nPayload; getLocalPayload(nUsable, p->flags, nPayload, &nLocal); if( nLocal<0 ) goto statPageIsCorrupt; pCell->nLocal = nLocal; assert( nPayload>=(u32)nLocal ); assert( nLocal<=(nUsable-35) ); if( nPayload>(u32)nLocal ){ int j; int nOvfl = ((nPayload - nLocal) + nUsable-4 - 1) / (nUsable - 4); pCell->nLastOvfl = (nPayload-nLocal) - (nOvfl-1) * (nUsable-4); pCell->nOvfl = nOvfl; |
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398 399 400 401 402 403 404 405 406 407 408 409 410 411 | } } } } } return SQLITE_OK; } /* ** Populate the pCsr->iOffset and pCsr->szPage member variables. Based on ** the current value of pCsr->iPageno. */ static void statSizeAndOffset(StatCursor *pCsr){ | > > > > > | 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 | } } } } } return SQLITE_OK; statPageIsCorrupt: p->flags = 0; p->nCell = 0; return SQLITE_OK; } /* ** Populate the pCsr->iOffset and pCsr->szPage member variables. Based on ** the current value of pCsr->iPageno. */ static void statSizeAndOffset(StatCursor *pCsr){ |
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