i3c: dw: Fix use-after-free in dw_i3c_master driver due to race condition

In dw_i3c_common_probe, &master->hj_work is bound with
dw_i3c_hj_work. And dw_i3c_master_irq_handler can call
dw_i3c_master_irq_handle_ibis function to start the work.

If we remove the module which will call dw_i3c_common_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

                                     | dw_i3c_hj_work
dw_i3c_common_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 dw_i3c_common_remove.

Fixes: 1dd728f5d4d4 ("i3c: master: Add driver for Synopsys DesignWare IP")
Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn>
Acked-by: Mukesh Kumar Savaliya <quic_msavaliy@quicinc.com>
Link: https://lore.kernel.org/r/bfc49c9527be5b513e7ceafeba314ca40a5be4bc.1732703537.git.xiaopei01@kylinos.cn
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
index 5b5c2e4bdc51601a125486d274db6d8f6bdbbf80..f1c564b4801ed7c99d143228f7b3fc310a74ff11 100644 (file)
--- a/drivers/i3c/master/dw-i3c-master.c
+++ b/drivers/i3c/master/dw-i3c-master.c
@@ -1647,6 +1647,7 @@ EXPORT_SYMBOL_GPL(dw_i3c_common_probe);
 
 void dw_i3c_common_remove(struct dw_i3c_master *master)
 {
+       cancel_work_sync(&master->hj_work);
        i3c_master_unregister(&master->base);
 
        pm_runtime_disable(master->dev);