From: Kees Cook <keescook@chromium.org>
To: Jiri Slaby <jirislaby@kernel.org>
Cc: Azeem Shaikh <azeemshaikh38@gmail.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-serial@vger.kernel.org,
Kefeng Wang <wangkefeng.wang@huawei.com>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] vt: Fix potential read overflow of kernel memory
Date: Thu, 31 Aug 2023 11:30:12 -0700 [thread overview]
Message-ID: <202308311123.EF07499@keescook> (raw)
In-Reply-To: <c44d1f9f-90e0-3e83-8394-854feb449539@kernel.org>
On Thu, Aug 31, 2023 at 07:32:18AM +0200, Jiri Slaby wrote:
> On 30. 08. 23, 23:28, Kees Cook wrote:
> > len = strlcpy(kbs, func_table[kb_func] ? : "", len);
> >
> > This is the anti-pattern (take the length of the _source_) we need to
> > remove.
>
> But len is the length of kbs, i.e. the destination. Or what am I missing?
strlcpy() returns the length of the _source_ string (i.e. it could be
greater than the input argument len). But there is no current flaw here
(since all sources are very short). We're just trying to remove strlcpy()
since it leads to unexpected results.
-Kees
--
Kees Cook
next prev parent reply other threads:[~2023-08-31 18:30 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-30 16:04 [PATCH] vt: Fix potential read overflow of kernel memory Azeem Shaikh
2023-08-30 17:57 ` Greg Kroah-Hartman
2023-08-30 19:25 ` Azeem Shaikh
2023-08-30 21:28 ` Kees Cook
2023-08-30 23:17 ` Dan Raymond
2023-08-30 23:48 ` Kees Cook
2023-08-31 5:45 ` Dan Raymond
2023-08-31 14:23 ` Azeem Shaikh
2023-09-15 2:56 ` Kees Cook
2023-08-31 5:32 ` Jiri Slaby
2023-08-31 14:21 ` Azeem Shaikh
2023-08-31 18:30 ` Kees Cook [this message]
2023-08-30 19:27 ` Kees Cook
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