From 609366e7a06d035990df78f1562291c3bf0d4a12 Mon Sep 17 00:00:00 2001 From: Kaixin Wang Date: Wed, 11 Sep 2024 23:35:44 +0800 Subject: [PATCH] i3c: master: cdns: Fix use after free vulnerability in cdns_i3c_master Driver Due to Race Condition 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 Link: https://lore.kernel.org/r/20240911153544.848398-1-kxwang23@m.fudan.edu.cn Signed-off-by: Alexandre Belloni --- 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 ee555255f1a2..fe4d59833ad5 100644 --- a/drivers/i3c/master/i3c-master-cdns.c +++ b/drivers/i3c/master/i3c-master-cdns.c @@ -1667,6 +1667,7 @@ static void cdns_i3c_master_remove(struct platform_device *pdev) { struct cdns_i3c_master *master = platform_get_drvdata(pdev); + cancel_work_sync(&master->hj_work); i3c_master_unregister(&master->base); clk_disable_unprepare(master->sysclk);