Netdev List
 help / color / mirror / Atom feed
From: Qingfang Deng <qingfang.deng@linux.dev>
To: Eric Dumazet <edumazet@google.com>
Cc: Jaeyoung Chung <jjy600901@snu.ac.kr>,
	andrew+netdev@lunn.ch, davem@davemloft.net, kuba@kernel.org,
	netdev@vger.kernel.org, pabeni@redhat.com, 726ksm@gmail.com,
	kees@kernel.org, linux-kernel@vger.kernel.org,
	eulgyukim@snu.ac.kr
Subject: Re: [BUG] KASAN: slab-use-after-free Read in slip_receive_buf
Date: Wed, 26 Aug 2026 13:53:48 +0800	[thread overview]
Message-ID: <f68f55d0-b012-4ea2-9623-2b8a63b2d0cd@linux.dev> (raw)
In-Reply-To: <CANn89iLr7+c_Hgxgj-odS10LW7CR_aTQr6ozFezKtYC6=vXG+A@mail.gmail.com>

On 2026/8/26 13:46, Eric Dumazet wrote:
> On Wed, Aug 26, 2026 at 7:38 AM Qingfang Deng <qingfang.deng@linux.dev> wrote:
>> Hi,
>>
>> On 2026/8/25 23:27, Eric Dumazet wrote:
>>> This rings a bell; I had a local syzbot report for this issue a while back.
>>>
>>> I think we should remove slip_hangup().
>> ppp_async.c and ppp_synctty.c have the same anti-pattern. Should we
>> remove theirs as well?
> Probably, akthough ppp_async and ppp_synctty historically suffered
> from this exact race, they added their own workaround: a global disc_data_lock,
> refcount_t refcnt, and wait_for_completion(&ap->dead) on every callback.
>
> Oh well.

Then the workaround should also be removed, according to the FIXME.

Relavent syzbot report:
https://lore.kernel.org/all/000000000000e8231f0601095c8e@google.com/


  reply	other threads:[~2026-08-26  5:53 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-25 15:06 [BUG] KASAN: slab-use-after-free Read in slip_receive_buf Jaeyoung Chung
2026-08-25 15:27 ` Eric Dumazet
2026-08-26  5:38   ` Qingfang Deng
2026-08-26  5:46     ` Eric Dumazet
2026-08-26  5:53       ` Qingfang Deng [this message]
2026-08-26  6:14         ` Eric Dumazet

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=f68f55d0-b012-4ea2-9623-2b8a63b2d0cd@linux.dev \
    --to=qingfang.deng@linux.dev \
    --cc=726ksm@gmail.com \
    --cc=andrew+netdev@lunn.ch \
    --cc=davem@davemloft.net \
    --cc=edumazet@google.com \
    --cc=eulgyukim@snu.ac.kr \
    --cc=jjy600901@snu.ac.kr \
    --cc=kees@kernel.org \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=pabeni@redhat.com \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox