On Sun, Sep 15, 2024 at 12:39:33AM +0800, Kaixin Wang wrote:
> In the svc_i3c_master_probe function, &master->hj_work is bound with
> svc_i3c_master_hj_work, &master->ibi_work is bound with
> svc_i3c_master_ibi_work. And svc_i3c_master_ibi_work can start the
> hj_work, svc_i3c_master_irq_handler can start the ibi_work.
>
> If we remove the module which will call svc_i3c_master_remove to
> make cleanup, it will free master->base through i3c_master_unregister
> while the work mentioned above will be used. The sequence of operations
> that may lead to a UAF bug is as follows:
>
> CPU0 CPU1
>
> | svc_i3c_master_hj_work
> svc_i3c_master_remove |
> i3c_master_unregister(&master->base)|
> device_unregister(&master->dev) |
> device_release |
> //free master->base |
> | i3c_master_do_daa(&master->base)
> | //use master->base
>
> Fix it by ensuring that the work is canceled before proceeding with the
> cleanup in svc_i3c_master_remove.
>
> Fixes: 0f74f8b6675c ("i3c: Make i3c_master_unregister() return void")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Kaixin Wang <kxwang23@xxxxxxxxxxxxxx>
> Reviewed-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
>
> ---
> v3:
> - add the tag "Cc: stable@xxxxxxxxxxxxxxx" in the sign-off area
> - Link to v2: https://lore.kernel.org/r/20240914154030.180-1-kxwang23@xxxxxxxxxxxxxx
> v2:
> - add fixes tag and cc stable, suggested by Frank
> - add Reviewed-by label from Miquel
> - Link to v1: https://lore.kernel.org/r/20240911150135.839946-1-kxwang23@xxxxxxxxxxxxxx
> ---
> drivers/i3c/master/svc-i3c-master.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> index 0a68fd1b81d4..e084ba648b4a 100644
> --- a/drivers/i3c/master/svc-i3c-master.c
> +++ b/drivers/i3c/master/svc-i3c-master.c
> @@ -1775,6 +1775,7 @@ static void svc_i3c_master_remove(struct platform_device *pdev)
> {
> struct svc_i3c_master *master = platform_get_drvdata(pdev);
>
> + cancel_work_sync(&master->hj_work);
> i3c_master_unregister(&master->base);
>
> pm_runtime_dont_use_autosuspend(&pdev->dev);
> --
> 2.39.1.windows.1
>
