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Re: [PATCH] commit.c: ensure strchrnul() doesn't scan beyond range

From
Kyle Lippincott <spectral@google.com>
Date
Feb 8, 2024, 19:52 UTC
Message-ID
<CAO_smVhsKHu0QrvpFbofd7y-Exhnk7=JUzffECNZQx=MWzmnsw@mail.gmail.com>
In-Reply-To
<xmqqil2yn3ey.fsf@gitster.g>
On Thu, Feb 8, 2024 at 11:48 AM Junio C Hamano <gitster@pobox.com> wrote:
Show 16 quoted lines
>
> René Scharfe <l.s.r@web.de> writes:
>
> > But anyway: If NULs are of no concern and we currently end parsing when
> > we see one in all cases, why do we need a _mem function at all?  The
> > original version of the function, find_commit_header(), should suffice.
> > check_nonce() could be run against the NUL-terminated sigcheck.payload
> > and check_cert_push_options() parses an entire strbuf, so there is no
> > risk of out-of-bounds access.
>
> If I recall correctly, the caller that does not pass strlen() as the
> payload length gives a length that is shorter than the buffer, i.e.
> "stop the parsing here, do not get confused into thinking the
> garbage after this point contains useful payload" was the reason why
> we have a separate "len".
>

I just rediscovered that. I think this probably should be something that caller (check_nonce) implements, then. Having a _mem function implies to me (though I'm very new to this codebase) that it supports embedded NULs, but that's not what's happening here.

Previous: Junio C HamanoNext: Jeff King
Message 7 of 13 in “commit.c: ensure strchrnul() doesn't scan beyond range”
  1. commit.c: ensure strchrnul() doesn't scan beyond rangeChandra Pratap via GitGitGadget, Feb 5, 2024
  2. René ScharfeFeb 5, 2024
  3. Junio C HamanoFeb 6, 2024
  4. Jeff KingFeb 8, 2024
  5. René ScharfeFeb 8, 2024
  6. Junio C HamanoFeb 8, 2024
  7. Kyle LippincottFeb 8, 2024
  8. Jeff KingFeb 8, 2024
  9. Junio C HamanoFeb 8, 2024
  10. Kyle LippincottFeb 6, 2024
  11. commit.c: ensure find_header_mem() doesn't scan beyond given rangeChandra Pratap via GitGitGadget, Feb 7, 2024
  12. René ScharfeFeb 7, 2024
  13. Junio C HamanoFeb 7, 2024

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