lkml.org 
[lkml]   [2022]   [Jan]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: spi: stm32-qspi: Update spi registering
From
Date
Hi Lukas

On 1/8/22 8:48 PM, Lukas Wunner wrote:
> On Thu, Jan 06, 2022 at 02:20:52PM +0100, patrice.chotard@foss.st.com wrote:
>> --- a/drivers/spi/spi-stm32-qspi.c
>> +++ b/drivers/spi/spi-stm32-qspi.c
>> @@ -784,7 +784,7 @@ static int stm32_qspi_probe(struct platform_device *pdev)
>> pm_runtime_enable(dev);
>> pm_runtime_get_noresume(dev);
>>
>> - ret = devm_spi_register_master(dev, ctrl);
>> + ret = spi_register_master(ctrl);
>> if (ret)
>> goto err_pm_runtime_free;
>>
>> @@ -817,6 +817,7 @@ static int stm32_qspi_remove(struct platform_device *pdev)
>> struct stm32_qspi *qspi = platform_get_drvdata(pdev);
>>
>> pm_runtime_get_sync(qspi->dev);
>> + spi_unregister_master(qspi->ctrl);
>> /* disable qspi */
>> writel_relaxed(0, qspi->io_base + QSPI_CR);
>> stm32_qspi_dma_free(qspi);
>
> NAK, this introduces a use-after-free because the "qspi" allocation
> is freed by spi_unregister_master(), yet is subsequently accessed.
>
> You need to convert the driver to devm_spi_alloc_master() to avoid that.
> Do it in the same patch to ease backporting.

Ok i see, spi_unregister_controller() is releasing the controller if it wasn't
previously devm allocated. I will make usage of devm_spi_alloc_master as you suggested.

>
> Please add a stable designation and a Fixes: tag. Chances are the patch
> needs to be backported all the way back to the release when the driver
> was first introduced.
>
> Thanks,
>
> Lukas
>
Thanks
Patrice

\
 
 \ /
  Last update: 2022-01-12 14:55    [W:0.062 / U:0.528 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site