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From: Linus Torvalds <torvalds@linux-foundation.org>
To: Alejandro Colomar <alx@kernel.org>
Cc: Yafang Shao <laoar.shao@gmail.com>,
	akpm@linux-foundation.org, justinstitt@google.com,
	 ebiederm@xmission.com, alexei.starovoitov@gmail.com,
	rostedt@goodmis.org,  catalin.marinas@arm.com,
	penguin-kernel@i-love.sakura.ne.jp,  linux-mm@kvack.org,
	linux-fsdevel@vger.kernel.org,
	 linux-trace-kernel@vger.kernel.org, audit@vger.kernel.org,
	 linux-security-module@vger.kernel.org, selinux@vger.kernel.org,
	 bpf@vger.kernel.org, netdev@vger.kernel.org,
	dri-devel@lists.freedesktop.org
Subject: Re: [PATCH v7 5/8] mm/util: Fix possible race condition in kstrdup()
Date: Sat, 17 Aug 2024 09:26:21 -0700	[thread overview]
Message-ID: <CAHk-=wi_U7S=R2ptr3dN21fOVbDGimY3-qpkSebeGtYh6pDCKA@mail.gmail.com> (raw)
In-Reply-To: <w6fx3gozq73slfpge4xucpezffrdioauzvoscdw2is5xf7viea@a4doumg264s4>

On Sat, 17 Aug 2024 at 01:48, Alejandro Colomar <alx@kernel.org> wrote:
>
> I would compact the above to:
>
>         len = strlen(s);
>         buf = kmalloc_track_caller(len + 1, gfp);
>         if (buf)
>                 strcpy(mempcpy(buf, s, len), "");

No, we're not doing this kind of horror.

If _FORTIFY_SOURCE has problems with a simple "memcpy and add NUL",
then _FORTIFY_SOURCE needs to be fixed.

We don't replace a "buf[len] = 0" with strcpy(,""). Yes, compilers may
simplify it, but dammit, it's an unreadable incomprehensible mess to
humans, and humans still matter a LOT more.

                Linus


  reply	other threads:[~2024-08-17 16:26 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-08-17  2:56 [PATCH v7 0/8] Improve the copy of task comm Yafang Shao
2024-08-17  2:56 ` [PATCH v7 1/8] Get rid of __get_task_comm() Yafang Shao
2024-08-17  2:56 ` [PATCH v7 2/8] auditsc: Replace memcpy() with strscpy() Yafang Shao
2024-08-17  2:56 ` [PATCH v7 3/8] security: Replace memcpy() with get_task_comm() Yafang Shao
2024-08-17  2:56 ` [PATCH v7 4/8] bpftool: Ensure task comm is always NUL-terminated Yafang Shao
2024-08-17  8:38   ` Alejandro Colomar
2024-08-18  2:27     ` Yafang Shao
2024-08-18  8:25       ` Alejandro Colomar
2024-08-17  2:56 ` [PATCH v7 5/8] mm/util: Fix possible race condition in kstrdup() Yafang Shao
2024-08-17  8:48   ` Alejandro Colomar
2024-08-17 16:26     ` Linus Torvalds [this message]
2024-08-17 17:03       ` Alejandro Colomar
2024-09-28 21:17     ` Kees Cook
2024-09-29  7:58       ` Alejandro Colomar
2024-09-29  9:48         ` Alejandro Colomar
2024-09-26 17:35   ` Andy Shevchenko
2024-09-27  8:57     ` Yafang Shao
2024-09-28 21:14   ` Kees Cook
2024-08-17  2:56 ` [PATCH v7 6/8] mm/util: Deduplicate code in {kstrdup,kstrndup,kmemdup_nul} Yafang Shao
2024-08-17  8:57   ` Alejandro Colomar
2024-08-17  9:05     ` Alejandro Colomar
2024-08-26  9:20     ` Alejandro Colomar
2024-08-26 13:13       ` Yafang Shao
2024-08-17  2:56 ` [PATCH v7 7/8] net: Replace strcpy() with strscpy() Yafang Shao
2024-08-17  2:56 ` [PATCH v7 8/8] drm: " Yafang Shao
2024-08-26  2:30 ` [PATCH v7 0/8] Improve the copy of task comm Yafang Shao
2024-08-28  1:19   ` Andrew Morton

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