linux-kernel - Re: [PATCH] libbpf: Replace strcpy() with memcpy() in bpf_object_

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAO9wTFjEJOfF7krFuV=DkZFzRU3FpRXtnq93UaX8=_Y=wnwbHw@mail.gmail.com>
Date: Thu, 17 Jul 2025 22:29:50 +0530
From: Suchit K <suchitkarunakaran@...il.com>
To: Yonghong Song <yonghong.song@...ux.dev>
Cc: ast@...nel.org, daniel@...earbox.net, andrii@...nel.org, 
	martin.lau@...ux.dev, eddyz87@...il.com, song@...nel.org, 
	john.fastabend@...il.com, kpsingh@...nel.org, sdf@...ichev.me, 
	haoluo@...gle.com, jolsa@...nel.org, bpf@...r.kernel.org, 
	skhan@...uxfoundation.org, linux-kernel-mentees@...ts.linux.dev, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] libbpf: Replace strcpy() with memcpy() in bpf_object__new()

On Thu, 17 Jul 2025 at 22:19, Yonghong Song <yonghong.song@...ux.dev> wrote:
>
>
>
> On 7/17/25 4:59 AM, Suchit Karunakaran wrote:
> > Replace the unsafe strcpy() call with memcpy() when copying the path
> > into the bpf_object structure. Since the memory is pre-allocated to
> > exactly strlen(path) + 1 bytes and the length is already known, memcpy()
> > is safer than strcpy().
>
> I don't understand in this particular context why strcpy()
> is less safer than memcpy(). Both of them will achieve the
> exactly same goal.
>

Sorry, I meant that strcpy() is generally considered unsafe because it
doesn't perform bounds checking. Its use is deprecated and
discouraged, as noted in Documentation/process/deprecated.rst. I made
this change with that in mind, although I'm not entirely certain
whether it's actually unsafe in this specific context.