Re: [PATCH] bus: fsl-mc: fix use-after-free in driver_override_show()

From: Ioana Ciornei
Date: Tue Dec 16 2025 - 08:22:31 EST


On Wed, Dec 03, 2025 at 01:44:38AM +0800, Gui-Dong Han wrote:
> The driver_override_show() function reads the driver_override string
> without holding the device_lock. However, driver_override_store() uses
> driver_set_override(), which modifies and frees the string while holding
> the device_lock.
>
> This can result in a concurrent use-after-free if the string is freed
> by the store function while being read by the show function.
>
> Fix this by holding the device_lock around the read operation.
>
> Fixes: 1f86a00c1159 ("bus/fsl-mc: add support for 'driver_override' in the mc-bus")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Gui-Dong Han <hanguidong02@xxxxxxxxx>

Reviewed-by: Ioana Ciornei <ioana.ciornei@xxxxxxx>

Thanks!