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PDF2JSON is a conversion library based on XPDF (3.02) which can be used for high performance PDF page by page conversion to JSON and XML format. It also supports compressing data to minimize size. PDF2JSON is available for Windows, OSX and Linux. Please see https://flowpaper.com for more information
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SEGV on DCTStream::transformDataUnit #27

Open strongcourage opened 5 years ago

strongcourage commented 5 years ago

Hi,

Our fuzzer found a crash due to an invalid read on the function DCTStream::transformDataUnit (the latest commit b671b64 on master - version 0.70).

PoC: https://github.com/strongcourage/PoCs/blob/master/pdf2json_b671b64/PoC_segv_DCTStream::transformDataUnit

Valgrind says:

valgrind pdf2json $PoC /dev/null
...
==23848== Invalid read of size 1
==23848==    at 0x43698B: DCTStream::transformDataUnit(unsigned short*, int*, unsigned char*) (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x43363B: DCTStream::readMCURow() (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x432FB6: DCTStream::getChar() (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x40947A: Object::streamGetChar() (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x48796F: Lexer::getChar() (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x487A83: Lexer::getObj(Object*) (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x489C19: Parser::shift() (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x489825: Parser::getObj(Object*, unsigned char*, CryptAlgorithm, int, int, int) (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x454759: Gfx::go(int) (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x454311: Gfx::display(Object*, int) (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x42A59E: Page::displaySlice(OutputDev*, double, double, int, int, int, int, int, int, int, Links*, int, Catalog*, int (*)(void*), void*) (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x42A14A: Page::display(OutputDev*, double, double, int, int, int, Links*, int, Catalog*, int (*)(void*), void*) (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==  Address 0x6fd636 is not stack'd, malloc'd or (recently) free'd
==23848== 
==23848== 
==23848== Process terminating with default action of signal 11 (SIGSEGV)
==23848==  Access not within mapped region at address 0x6FD636
==23848==    at 0x43698B: DCTStream::transformDataUnit(unsigned short*, int*, unsigned char*) (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x43363B: DCTStream::readMCURow() (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x432FB6: DCTStream::getChar() (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x40947A: Object::streamGetChar() (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x48796F: Lexer::getChar() (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x487A83: Lexer::getObj(Object*) (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x489C19: Parser::shift() (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x489825: Parser::getObj(Object*, unsigned char*, CryptAlgorithm, int, int, int) (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x454759: Gfx::go(int) (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x454311: Gfx::display(Object*, int) (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x42A59E: Page::displaySlice(OutputDev*, double, double, int, int, int, int, int, int, int, Links*, int, Catalog*, int (*)(void*), void*) (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==    by 0x42A14A: Page::display(OutputDev*, double, double, int, int, int, Links*, int, Catalog*, int (*)(void*), void*) (in /home/dungnguyen/PoCs/pdf2json_b671b64/pdf2json)
==23848==  If you believe this happened as a result of a stack
==23848==  overflow in your program's main thread (unlikely but
==23848==  possible), you can try to increase the size of the
==23848==  main thread stack using the --main-stacksize= flag.
==23848==  The main thread stack size used in this run was 8388608.
==23848== 
==23848== HEAP SUMMARY:
==23848==     in use at exit: 230,627 bytes in 1,819 blocks
==23848==   total heap usage: 2,242 allocs, 423 frees, 357,101 bytes allocated
==23848== 
==23848== LEAK SUMMARY:
==23848==    definitely lost: 16 bytes in 1 blocks
==23848==    indirectly lost: 8 bytes in 1 blocks
==23848==      possibly lost: 0 bytes in 0 blocks
==23848==    still reachable: 230,603 bytes in 1,817 blocks
==23848==         suppressed: 0 bytes in 0 blocks
==23848== Rerun with --leak-check=full to see details of leaked memory
==23848== 
==23848== For counts of detected and suppressed errors, rerun with: -v
==23848== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
Segmentation fault

Thanks, Manh Dung