From: Junio C Hamano <gitster@pobox.com>
To: Florian Schmidt <flosch@nutanix.com>
Cc: git@vger.kernel.org,
Jonathan Davies <jonathan.davies@nutanix.com>,
Phillip Wood <phillip.wood@dunelm.org.uk>,
Denton Liu <liu.denton@gmail.com>
Subject: Re: [PATCH] wt-status: Don't find scissors line beyond buf len
Date: Thu, 07 Mar 2024 11:35:34 -0800 [thread overview]
Message-ID: <xmqqsf11ltrt.fsf@gitster.g> (raw)
In-Reply-To: <20240307183743.219951-1-flosch@nutanix.com> (Florian Schmidt's message of "Thu, 7 Mar 2024 18:37:38 +0000")
Florian Schmidt <flosch@nutanix.com> writes:
> Side remark: Since strstr() doesn't consider len, and will always search
> up to a null byte, I now wonder whether it would be safer to create a
> new strbuf that only contains the len bytes we want to operate on.
That is a valid concern in general, but does not seem to apply to
the current codebase. Thanks for being careful.
Two of the three callers of wt_status_locate_end() feed the pointer
into a piece of memory that is owned by strbuf, which guarantees
that the memory has an extra NUL to terminate it as a string even if
you did
strbuf buf = STRBUF_INIT;
strbuf_addch(&buf, 'A');
The other one is in commit.c:ignored_log_message_bytes() that still
takes <buf, len> as input, but again, two of its three callers call
it with a pointer that points at the beginning of memory held by an
instance of strbuf.
That leaves us trailer.c:find_end_of_log_message() the only one to
worry about, but it uses strlen() on the pointer before calling
ignored_log_message_bytes() so the region of the memory pointed at
by the pointer is assumed to be NUL-terminated already, and
presumably (I didn't follow the logic there too closely) the length
is also computed within that NUL-terminated string.
next prev parent reply other threads:[~2024-03-07 19:35 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-07 18:37 [PATCH] wt-status: Don't find scissors line beyond buf len Florian Schmidt
2024-03-07 19:20 ` Junio C Hamano
2024-03-07 20:47 ` Junio C Hamano
2024-03-07 21:09 ` Eric Sunshine
2024-03-07 21:15 ` Kristoffer Haugsbakk
2024-03-07 21:24 ` Junio C Hamano
2024-03-07 21:26 ` Eric Sunshine
2024-03-07 21:30 ` Kristoffer Haugsbakk
2024-03-08 9:08 ` Florian Schmidt
2024-03-08 15:26 ` Junio C Hamano
2024-03-08 17:43 ` Florian Schmidt
2024-04-06 1:37 ` Linus Arver
2024-03-07 19:35 ` Junio C Hamano [this message]
2024-03-08 9:13 ` Florian Schmidt
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