Twitter Updates

    follow me on Twitter

    List for 4.5% and get 1% cash back on your purchase

    Tuesday, May 19, 2020

    C++ Std::Condition_Variable Null Pointer Derreference


    This story is about a bug generated by g++ and clang compilers (at least)
    The condition_variables is a feature on the standard library of c++ (libstdc++), when its compiled statically a weird asm code is generated.


    Any example on the link below will crash if its compiled statically:
     https://en.cppreference.com/w/cpp/thread/condition_variable



    In this case the condition_variable.wait() crashed, but this happens with other methods, a simple way to trigger it:




    If this program is compiled dynamically the crash doesn't occur:

    Looking the dissasembly there is a surprise created by the compiler:


    Compilers:
        g++  9.2.1+20200130-2
        clang++ v9

    Both compilers are generating the "call 0x00"

    If we check this call in a dynamic compiled:




    The implementation of condition_variable in github:
    https://github.com/gcc-mirror/gcc/blob/b7c9bd36eaacac42631b882dc67a6f0db94de21c/libstdc%2B%2B-v3/include/std/condition_variable


    The compilers can't copile well this code in static,  and same happens on  other condition_variable methods.
    I would say the _lock is being assembled improperly in static, is not exacly a null pointer derreference but the effects are the same, executing code at address 0x00 which on linux is a crash on most of cases.

    More information

    1. Hacking The Art Of Exploitation
    2. Curso Completo De Hacking Ético
    3. Como Convertirse En Hacker
    4. Hacker Pelicula
    5. Hacking Wifi Windows
    6. Como Hackear
    7. 101 Hacking
    8. Cracker Informatico
    9. Hacking Wikipedia
    10. Hacking Google Home Mini
    11. Rom Hacking
    12. Hacking Virus
    13. Hacking Y Forensic Desarrolle Sus Propias Herramientas En Python Pdf
    14. Hacking Movies
    15. Hacking Tools

    No comments:

    Post a Comment

    Home for sale- $2,000 rebate!

    Ready Real Estate slide show

    Become a fan of my page

    Sheree Dutton, Reatlor, DFW, Texas on Facebook
    Powered By Blogger

    Pandora Faves

    Back on the market, price reduced, 1% cash back rebate offered

    Sheree Dutton | Ready Real Estate | 817-975-0461
    222 Birchwood, Azle, TX
    Back on the market, price reduced and 15 cash back rebate offered!
    3BR/2BA Single Family House
    offered at $102,500
    Year Built 2006
    Sq Footage 1,142
    Bedrooms 3
    Bathrooms 2 full, 0 partial
    Floors 1
    Parking 3 Covered spaces
    Lot Size .225 acres
    HOA/Maint $0 per month

    DESCRIPTION


    Wow, talk about pride of ownership! This house has too many upgrades to count, and is so well cared for. You must see it to believe it! A lot of value in this perfect starter home.

    OPEN HOUSE SUNDAY MAY 3RD 2+5 pm

    see additional photos below
    PROPERTY FEATURES

    - Central A/C - Central heat - Fireplace
    - High/Vaulted ceiling - Walk-in closet - Tile floor
    - Living room - Breakfast nook - Dishwasher
    - Refrigerator - Stove/Oven - Microwave
    - Laundry area - inside - Balcony, Deck, or Patio - Yard

    OTHER SPECIAL FEATURES

    - 1 car garage, covered carport for 2 cars
    - covered wood deck in backyard
    - gutters
    - storage shed
    - newly stained wood fence
    - electric fireplace added, with tile hearth
    - upgraded ceiling fans and light fixtures
    - island in kitchen

    ADDITIONAL PHOTOS


    Fantastic curb appeal

    covered wood deck in back

    living room

    kitchen with island

    breakfast nook

    master bedroom
    Contact info:
    Sheree Dutton
    Ready Real Estate
    817-975-0461
    For sale by agent/broker

    powered by postlets Equal Opportunity Housing
    Posted: Sep 11, 2009, 7:31am PDT

    Blog Archive