On Thu, 3 Feb 2022 at 17:47, Vladimir Zapolskiy
<vladimir.zapolskiy@xxxxxxxxxx> wrote:
>
> There is a minor chance for a race, if a pointer to an i2c-bus subnode
> is stored and then reused after releasing its reference, and it would
> be sufficient to get one more reference under a loop over children
> subnodes.
>
> Fixes: e517526195de ("i2c: Add Qualcomm CCI I2C driver")
> Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@xxxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-qcom-cci.c | 14 ++++++++++----
> 1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-qcom-cci.c b/drivers/i2c/busses/i2c-qcom-cci.c
> index fd4260d18577..cf54f1cb4c57 100644
> --- a/drivers/i2c/busses/i2c-qcom-cci.c
> +++ b/drivers/i2c/busses/i2c-qcom-cci.c
> @@ -558,7 +558,7 @@ static int cci_probe(struct platform_device *pdev)
> cci->master[idx].adap.quirks = &cci->data->quirks;
> cci->master[idx].adap.algo = &cci_algo;
> cci->master[idx].adap.dev.parent = dev;
> - cci->master[idx].adap.dev.of_node = child;
> + cci->master[idx].adap.dev.of_node = of_node_get(child);
> cci->master[idx].master = idx;
> cci->master[idx].cci = cci;
>
> @@ -643,8 +643,10 @@ static int cci_probe(struct platform_device *pdev)
> continue;
>
> ret = i2c_add_adapter(&cci->master[i].adap);
> - if (ret < 0)
> + if (ret < 0) {
> + of_node_put(cci->master[i].adap.dev.of_node);
> goto error_i2c;
> + }
> }
>
> pm_runtime_set_autosuspend_delay(dev, MSEC_PER_SEC);
> @@ -656,8 +658,10 @@ static int cci_probe(struct platform_device *pdev)
>
> error_i2c:
> for (--i ; i >= 0; i--) {
> - if (cci->master[i].cci)
> + if (cci->master[i].cci) {
> i2c_del_adapter(&cci->master[i].adap);
> + of_node_put(cci->master[i].adap.dev.of_node);
> + }
> }
> error:
> disable_irq(cci->irq);
> @@ -673,8 +677,10 @@ static int cci_remove(struct platform_device *pdev)
> int i;
>
> for (i = 0; i < cci->data->num_masters; i++) {
> - if (cci->master[i].cci)
> + if (cci->master[i].cci) {
> i2c_del_adapter(&cci->master[i].adap);
> + of_node_put(cci->master[i].adap.dev.of_node);
> + }
> cci_halt(cci, i);
> }
>
> --
> 2.33.0
>
Reviewed-by: Robert Foss <robert.foss@xxxxxxxxxx>
