• Show log

    Commit

  • Hash : 174b7a32
    Author : Patrick Steinhardt
    Date : 2019-09-19T12:24:06

    buffer: fix printing into out-of-memory buffer Before printing into a `git_buf` structure, we always call `ENSURE_SIZE` first. This macro will reallocate the buffer as-needed depending on whether the current amount of allocated bytes is sufficient or not. If `asize` is big enough, then it will just do nothing, otherwise it will call out to `git_buf_try_grow`. But in fact, it is insufficient to only check `asize`. When we fail to allocate any more bytes e.g. via `git_buf_try_grow`, then we set the buffer's pointer to `git_buf__oom`. Note that we touch neither `asize` nor `size`. So if we just check `asize > targetsize`, then we will happily let the caller of `ENSURE_SIZE` proceed with an out-of-memory buffer. As a result, we will print all bytes into the out-of-memory buffer instead, resulting in an out-of-bounds write. Fix the issue by having `ENSURE_SIZE` verify that the buffer is not marked as OOM. Add a test to verify that we're not writing into the OOM buffer.

  • README.md

  • Writing Clar tests for libgit2

    For information on the Clar testing framework and a detailed introduction please visit:

    https://github.com/vmg/clar

    • Write your modules and tests. Use good, meaningful names.

    • Make sure you actually build the tests by setting:

        cmake -DBUILD_CLAR=ON build/
    • Test:

        ./build/libgit2_clar
    • Make sure everything is fine.

    • Send your pull request. That’s it.

    Memory leak checks

    These are automatically run as part of CI, but if you want to check locally:

    Linux

    Uses valgrind:

    $ cmake -DBUILD_CLAR=ON -DVALGRIND=ON ..
    $ cmake --build .
    $ valgrind --leak-check=full --show-reachable=yes --num-callers=50 --suppressions=../libgit2_clar.supp \
      ./libgit2_clar

    macOS

    Uses leaks, which requires XCode installed:

    $ MallocStackLogging=1 MallocScribble=1 MallocLogFile=/dev/null CLAR_AT_EXIT="leaks -quiet \$PPID" \
      ./libgit2_clar