Re:[PATCH v3] HSI: ssi_protocol: Fix use after free vulnerability in ssi_protocol Driver Due to Race Condition

Kaixin Wang
2025-02-24T03:24:49Z

At 2024-09-18 20:07:50, "Kaixin Wang" <kxwang23@m.fudan.edu.cn> wrote:
>In the ssi_protocol_probe() function, &ssi->work is bound with
>ssip_xmit_work(), In ssip_pn_setup(), the ssip_pn_xmit() function
>within the ssip_pn_ops structure is capable of starting the
>work.
>
>If we remove the module which will call ssi_protocol_remove()
>to make a cleanup, it will free ssi through kfree(ssi),
>while the work mentioned above will be used. The sequence
>of operations that may lead to a UAF bug is as follows:
>
>CPU0 CPU1
>
> | ssip_xmit_work
>ssi_protocol_remove |
>kfree(ssi); |
> | struct hsi_client *cl = ssi->cl;
> | // use ssi
>
>Fix it by ensuring that the work is canceled before proceeding
>with the cleanup in ssi_protocol_remove().
>
>Signed-off-by: Kaixin Wang <kxwang23@m.fudan.edu.cn>
>Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
>
>---
>v3:
>- refer to the functions in the form of func() in the description message.
>- Link to v2: https://lore.kernel.org/r/20240914172142.328-1-kxwang23@m.fudan.edu.cn
>v2:
>- cancel the work in ssip_reset(), suggested by Sebastian
>- add the Acked-by label from Andy
>- Link to v1: https://lore.kernel.org/r/20240911151915.844957-1-kxwang23@m.fudan.edu.cn
>---
> drivers/hsi/clients/ssi_protocol.c | 1 +
> 1 file changed, 1 insertion(+)
>
>diff --git a/drivers/hsi/clients/ssi_protocol.c b/drivers/hsi/clients/ssi_protocol.c
>index afe470f3661c..6105ea9a6c6a 100644
>--- a/drivers/hsi/clients/ssi_protocol.c
>+++ b/drivers/hsi/clients/ssi_protocol.c
>@@ -401,6 +401,7 @@ static void ssip_reset(struct hsi_client *cl)
> del_timer(&ssi->rx_wd);
> del_timer(&ssi->tx_wd);
> del_timer(&ssi->keep_alive);
>+ cancel_work_sync(&ssi->work);
> ssi->main_state = 0;
> ssi->send_state = 0;
> ssi->recv_state = 0;
>--
>2.39.1.windows.1

>
Hi, I noticed that there are no relevant replies to this patch that I sent several months ago. Is it missed?