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

diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
index 8d694672c110..dbcd3984f257 100644
--- a/drivers/i3c/master/dw-i3c-master.c
+++ b/drivers/i3c/master/dw-i3c-master.c
@@ -1624,6 +1624,7 @@ 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);
-- 
2.34.1

On Wed, 27 Nov 2024 18:35:11 +0800, Pei Xiao wrote:
> 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:
> 
> [...]

Applied, thanks!

[1/1] i3c: dw: Fix use-after-free in dw_i3c_master driver due to race condition
      https://git.kernel.org/abelloni/c/b75439c945b9

Best regards,

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com