All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Shengzhuo Wei" <me@cherr.cc>
To: "David Laight" <david.laight.linux@gmail.com>
Cc: "Richard Weinberger" <richard@nod.at>,
	 "Anton Ivanov" <anton.ivanov@cambridgegreys.com>,
	 "Johannes Berg" <johannes@sipsolutions.net>,
	 "Dan Carpenter" <error27@gmail.com>,
	 "Andrew Morton" <akpm@linux-foundation.org>,
	 "Jeff Dike" <jdike@addtoit.com>, "Yao Zi" <me@ziyao.cc>,
	 <linux-um@lists.infradead.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] um: proc/exitcode: fix simple_strtol() out-of-bounds read
Date: Thu, 23 Apr 2026 11:28:45 +0800	[thread overview]
Message-ID: <aemR7Ur4H9dnKQ57@pve.cherr> (raw)
In-Reply-To: <20260422214507.0078c8ba@pumpkin>

On 2026-04-22 21:45, David Laight wrote:
> On Thu, 23 Apr 2026 01:39:25 +0800
> "Shengzhuo Wei" <me@cherr.cc> wrote:
> 
> > The stack buffer 'buf' is declared as char[sizeof("nnnnn\0")] (7 bytes)
> > and the copy size is min(count, sizeof(buf)).  When a user writes 7 or
> > more bytes, copy_from_user fills all 7 bytes without a NUL terminator.
> > The subsequent call to simple_strtol() expects a NUL-terminated string
> > and will read past the end of buf on the stack.
> 
> You should probably also mention that write(, "123", 3) will lead to
> buf[3] being read - which is uninitialised stack.
> 
> 	David

Thanks for the review, will fix in v2.

Best regards


  reply	other threads:[~2026-04-23  3:29 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-22 17:39 [PATCH] um: proc/exitcode: fix simple_strtol() out-of-bounds read Shengzhuo Wei
2026-04-22 20:45 ` David Laight
2026-04-23  3:28   ` Shengzhuo Wei [this message]
2026-04-27 13:36 ` Shengzhuo Wei

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=aemR7Ur4H9dnKQ57@pve.cherr \
    --to=me@cherr.cc \
    --cc=akpm@linux-foundation.org \
    --cc=anton.ivanov@cambridgegreys.com \
    --cc=david.laight.linux@gmail.com \
    --cc=error27@gmail.com \
    --cc=jdike@addtoit.com \
    --cc=johannes@sipsolutions.net \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-um@lists.infradead.org \
    --cc=me@ziyao.cc \
    --cc=richard@nod.at \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.