spmi: mediatek: Fix UAF on device remove

[ Upstream commit e821d50ab5b956ed0effa49faaf29912fd4106d9 ]

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: Fei Shao <fshao@chromium.org>
Signed-off-by: Yu-Che Cheng <giver@chromium.org>
Link: https://lore.kernel.org/r/20230717173934.1.If004a6e055a189c7f2d0724fa814422c26789839@changeid
Tested-by: Fei Shao <fshao@chromium.org>
Reviewed-by: Fei Shao <fshao@chromium.org>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20231206231733.4031901-3-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/spmi/spmi-mtk-pmif.c b/drivers/spmi/spmi-mtk-pmif.c
index 54c35f5..1261f38 100644 (file)
--- a/drivers/spmi/spmi-mtk-pmif.c
+++ b/drivers/spmi/spmi-mtk-pmif.c
@@ -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);
 }