netdev - Re: [PATCH net v2] team: fix qom_list corruption by using list_del_init

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aTls21jR6BvTaV-k@horms.kernel.org>
Date: Wed, 10 Dec 2025 12:51:39 +0000
From: Simon Horman <horms@...nel.org>
To: Dharanitharan R <dharanitharan725@...il.com>
Cc: syzbot+422806e5f4cce722a71f@...kaller.appspotmail.com,
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH net v2] team: fix qom_list corruption by using
 list_del_init_rcu()

On Wed, Dec 10, 2025 at 05:31:05AM +0000, Dharanitharan R wrote:
> In __team_queue_override_port_del(), repeated deletion of the same port
> using list_del_rcu() could corrupt the RCU-protected qom_list. This
> happens if the function is called multiple times on the same port, for
> example during port removal or team reconfiguration.
> 
> This patch replaces list_del_rcu() with list_del_init_rcu() to:
> 
>   - Ensure safe repeated deletion of the same port
>   - Keep the RCU list consistent
>   - Avoid potential use-after-free and list corruption issues
> 
> Testing:
>   - Syzbot-reported crash is eliminated in testing.
>   - Kernel builds and runs cleanly
> 
> Fixes: 108f9405ce81 ("team: add queue override configuration mechanism")
> Reported-by: syzbot+422806e5f4cce722a71f@...kaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=422806e5f4cce722a71f
> Signed-off-by: Dharanitharan R <dharanitharan725@...il.com>

Thanks for addressing my review of v1.
The commit message looks much better to me.

However, I am unable to find the cited commit in net.

And I am still curious about the cause: are you sure it is repeated deletion?

> ---
>  drivers/net/team/team_core.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/team/team_core.c b/drivers/net/team/team_core.c
> index 4d5c9ae8f221..d6d724b52dbf 100644
> --- a/drivers/net/team/team_core.c
> +++ b/drivers/net/team/team_core.c
> @@ -823,7 +823,8 @@ static void __team_queue_override_port_del(struct team *team,
>  {
>  	if (!port->queue_id)
>  		return;
> -	list_del_rcu(&port->qom_list);
> +	/* Ensure safe repeated deletion */
> +	list_del_init_rcu(&port->qom_list);

When applied against net this does not compile
as list_del_init_rcu (as opposed to hlist_del_init_rcu) does
not seem to exist in that tree. Am I missing something?

>  }
>  
>  static bool team_queue_override_port_has_gt_prio_than(struct team_port *port,
> -- 
> 2.43.0

-- 
pw-bot: changes-requested