Commit e821d50a authored by Yu-Che Cheng's avatar Yu-Che Cheng Committed by Greg Kroah-Hartman
Browse files

spmi: mediatek: Fix UAF on device remove 



The pmif driver data that contains the clocks is allocated along with
spmi_controller.
On device remove, spmi_controller will be freed first, and then devres
, including the clocks, will be cleanup.
This leads to UAF because putting the clocks will access the clocks in
the pmif driver data, which is already freed along with spmi_controller.

This can be reproduced by enabling DEBUG_TEST_DRIVER_REMOVE and
building the kernel with KASAN.

Fix the UAF issue by using unmanaged clk_bulk_get() and putting the
clocks before freeing spmi_controller.

Reported-by: default avatarFei Shao <fshao@chromium.org>
Signed-off-by: default avatarYu-Che Cheng <giver@chromium.org>
Link: https://lore.kernel.org/r/20230717173934.1.If004a6e055a189c7f2d0724fa814422c26789839@changeid


Tested-by: default avatarFei Shao <fshao@chromium.org>
Reviewed-by: default avatarFei Shao <fshao@chromium.org>
Reviewed-by: default avatarChen-Yu Tsai <wenst@chromium.org>
Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20231206231733.4031901-3-sboyd@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f200fff8

drivers/spmi/spmi-mtk-pmif.c

+5 −2
Original line number Diff line number Diff line
@@ -475,7 +475,7 @@ static int mtk_spmi_probe(struct platform_device *pdev) 
	for (i = 0; i < arb->nclks; i++)

		arb->clks[i].id = pmif_clock_names[i];



	err = devm_clk_bulk_get(&pdev->dev, arb->nclks, arb->clks);

	err = clk_bulk_get(&pdev->dev, arb->nclks, arb->clks);

	if (err) {

		dev_err(&pdev->dev, "Failed to get clocks: %d\n", err);

		goto err_put_ctrl;
@@ -484,7 +484,7 @@ static int mtk_spmi_probe(struct platform_device *pdev) 
	err = clk_bulk_prepare_enable(arb->nclks, arb->clks);

	if (err) {

		dev_err(&pdev->dev, "Failed to enable clocks: %d\n", err);

		goto err_put_ctrl;

		goto err_put_clks;

	}



	ctrl->cmd = pmif_arb_cmd;
@@ -510,6 +510,8 @@ static int mtk_spmi_probe(struct platform_device *pdev) 


err_domain_remove:

	clk_bulk_disable_unprepare(arb->nclks, arb->clks);

err_put_clks:

	clk_bulk_put(arb->nclks, arb->clks);

err_put_ctrl:

	spmi_controller_put(ctrl);

	return err;
@@ -521,6 +523,7 @@ static void mtk_spmi_remove(struct platform_device *pdev) 
	struct pmif *arb = spmi_controller_get_drvdata(ctrl);



	clk_bulk_disable_unprepare(arb->nclks, arb->clks);

	clk_bulk_put(arb->nclks, arb->clks);

	spmi_controller_remove(ctrl);

	spmi_controller_put(ctrl);

}