public inbox for netdev@vger.kernel.org
 help / color / mirror / Atom feed
From: Cong Wang <xiyou.wangcong@gmail.com>
To: Hyunwoo Kim <imv4bel@gmail.com>
Cc: vinicius.gomes@intel.com, jhs@mojatatu.com, jiri@resnulli.us,
	davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
	pabeni@redhat.com, horms@kernel.org, vladimir.oltean@nxp.com,
	netdev@vger.kernel.org, v4bel@theori.io
Subject: Re: [PATCH v2] net/sched: fix use-after-free in taprio_dev_notifier
Date: Thu, 12 Jun 2025 13:23:38 -0700	[thread overview]
Message-ID: <aEs3Sotbf81FShq3@pop-os.localdomain> (raw)
In-Reply-To: <aEq3J4ODxH7x+neT@v4bel-B760M-AORUS-ELITE-AX>

On Thu, Jun 12, 2025 at 07:16:55AM -0400, Hyunwoo Kim wrote:
> diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
> index 14021b812329..bd2b02d1dc63 100644
> --- a/net/sched/sch_taprio.c
> +++ b/net/sched/sch_taprio.c
> @@ -1320,6 +1320,7 @@ static int taprio_dev_notifier(struct notifier_block *nb, unsigned long event,
>  	if (event != NETDEV_UP && event != NETDEV_CHANGE)
>  		return NOTIFY_DONE;
>  
> +	rcu_read_lock();
>  	list_for_each_entry(q, &taprio_list, taprio_list) {
>  		if (dev != qdisc_dev(q->root))
>  			continue;
> @@ -1328,16 +1329,17 @@ static int taprio_dev_notifier(struct notifier_block *nb, unsigned long event,

There is a taprio_set_picos_per_byte() call here, it calls
__ethtool_get_link_ksettings() which could be blocking.

For instance, gve_get_link_ksettings() calls
gve_adminq_report_link_speed() which is a blocking function.

So I am afraid we can't enforce an atomic context here.

Sorry.
Cong

  parent reply	other threads:[~2025-06-12 20:23 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-06-12 11:16 [PATCH v2] net/sched: fix use-after-free in taprio_dev_notifier Hyunwoo Kim
2025-06-12 11:46 ` Eric Dumazet
2025-06-12 20:23 ` Cong Wang [this message]
2025-06-13  3:36   ` Hyunwoo Kim
2025-06-13 20:52     ` Vladimir Oltean
2025-06-14  0:46       ` Hyunwoo Kim
2025-06-13 20:33   ` Vladimir Oltean

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=aEs3Sotbf81FShq3@pop-os.localdomain \
    --to=xiyou.wangcong@gmail.com \
    --cc=davem@davemloft.net \
    --cc=edumazet@google.com \
    --cc=horms@kernel.org \
    --cc=imv4bel@gmail.com \
    --cc=jhs@mojatatu.com \
    --cc=jiri@resnulli.us \
    --cc=kuba@kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=pabeni@redhat.com \
    --cc=v4bel@theori.io \
    --cc=vinicius.gomes@intel.com \
    --cc=vladimir.oltean@nxp.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