From: Anirudh Rayabharam <mail@anirudhrb.com>
To: Johan Hovold <johan@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-usb@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, stable@vger.kernel.org,
Leonardo Antoniazzi <leoanto@aruba.it>,
mail@anirudhrb.com
Subject: Re: [PATCH] net: hso: fix NULL-deref on disconnect regression
Date: Mon, 26 Apr 2021 19:31:38 +0530 [thread overview]
Message-ID: <YIbHwqG6eukP9uQg@anirudhrb.com> (raw)
In-Reply-To: <20210426081149.10498-1-johan@kernel.org>
On Mon, Apr 26, 2021 at 10:11:49AM +0200, Johan Hovold wrote:
> Commit 8a12f8836145 ("net: hso: fix null-ptr-deref during tty device
> unregistration") fixed the racy minor allocation reported by syzbot, but
> introduced an unconditional NULL-pointer dereference on every disconnect
> instead.
>
> Specifically, the serial device table must no longer be accessed after
> the minor has been released by hso_serial_tty_unregister().
>
> Fixes: 8a12f8836145 ("net: hso: fix null-ptr-deref during tty device unregistration")
> Cc: stable@vger.kernel.org
> Cc: Anirudh Rayabharam <mail@anirudhrb.com>
> Reported-by: Leonardo Antoniazzi <leoanto@aruba.it>
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---
> drivers/net/usb/hso.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
> index 9bc58e64b5b7..3ef4b2841402 100644
> --- a/drivers/net/usb/hso.c
> +++ b/drivers/net/usb/hso.c
> @@ -3104,7 +3104,7 @@ static void hso_free_interface(struct usb_interface *interface)
> cancel_work_sync(&serial_table[i]->async_put_intf);
> cancel_work_sync(&serial_table[i]->async_get_intf);
> hso_serial_tty_unregister(serial);
> - kref_put(&serial_table[i]->ref, hso_serial_ref_free);
> + kref_put(&serial->parent->ref, hso_serial_ref_free);
> }
> }
Ah, my bad. Thanks Johan for the fix!
Reviewed-by: Anirudh Rayabharam <mail@anirudhrb.com>
- Anirudh.
next prev parent reply other threads:[~2021-04-26 14:02 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-26 8:11 [PATCH] net: hso: fix NULL-deref on disconnect regression Johan Hovold
[not found] ` <20210426112911.fb3593c3a9ecbabf98a13313@aruba.it>
2021-04-26 9:35 ` Johan Hovold
2021-04-26 9:50 ` Greg Kroah-Hartman
2021-04-26 20:09 ` David Miller
2021-04-27 6:11 ` Greg KH
2021-04-26 14:01 ` Anirudh Rayabharam [this message]
2021-04-26 20:00 ` patchwork-bot+netdevbpf
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