• unknown's avatar
    BUG#11392 - fulltext search bug · b698b6fd
    unknown authored
    Fulltext boolean mode phrase search may crash server on platforms
    where size of pointer is not equal to size of unsigned integer
    (in other words some 64-bit platforms).
    
    The problem was integer overflow.
    
    Affects 4.1 only.
    
    
    myisam/ft_boolean_search.c:
      my_match_t::beg is unsigned int, that means type of expression
      (m[0].beg - 1) has unsigned type too. It may happen that instr()
      finds substring in the beggining of passed string, returning
      m[0].beg equal to 0. In this case value of expression (m[0].beg - 1)
      is equal to MAX_UINT.
      
      This is not a problem on platforms where sizeof(pointer) equals to
      sizeof(uint). That means ptr[(uint)-1] = ptr[(uint)MAX_UINT] = ptr - 1.
      
      On some 64-bit platforms where sizeof(pointer) is 8 and sizeof(uint)
      is 4, wrong address gets accessed. In other words ptr[(uint)-1] is
      equal to ptr + MAX_UINT.
    mysql-test/r/fulltext.result:
      A test case for BUG#11392.
    mysql-test/t/fulltext.test:
      A test case for BUG#11392.
    b698b6fd
fulltext.result 17.7 KB