On Fri, Jan 03, 2025 at 03:04:20PM +0800, jianqi.ren.cn@windriver.com wrote:

From: Kaixin Wang kxwang23@m.fudan.edu.cn

[ Upstream commit 609366e7a06d035990df78f1562291c3bf0d4a12 ]

In the cdns_i3c_master_probe function, &master->hj_work is bound with cdns_i3c_master_hj. And cdns_i3c_master_interrupt can call cnds_i3c_master_demux_ibis function to start the work.

If we remove the module which will call cdns_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

                                 | cdns_i3c_master_hj

cdns_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 cdns_i3c_master_remove.

Signed-off-by: Kaixin Wang kxwang23@m.fudan.edu.cn Link: https://lore.kernel.org/r/20240911153544.848398-1-kxwang23@m.fudan.edu.cn Signed-off-by: Alexandre Belloni alexandre.belloni@bootlin.com Signed-off-by: Jianqi Ren jianqi.ren.cn@windriver.com

---

drivers/i3c/master/i3c-master-cdns.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/drivers/i3c/master/i3c-master-cdns.c b/drivers/i3c/master/i3c-master-cdns.c index b9cfda6ae9ae..4473c0b1ae2e 100644 --- a/drivers/i3c/master/i3c-master-cdns.c +++ b/drivers/i3c/master/i3c-master-cdns.c @@ -1668,6 +1668,7 @@ static int cdns_i3c_master_remove(struct platform_device *pdev) struct cdns_i3c_master *master = platform_get_drvdata(pdev); int ret;

• cancel_work_sync(&master->hj_work); ret = i3c_master_unregister(&master->base); if (ret) return ret;

-- 2.25.1

Does not apply to 6.1.y :(