From: Dmitriy Ulitin ulitin@ispras.ru
[ Upstream commit 548fa43a58696450c15b8f5564e99589c5144664 ]
At the moment of enabling irq handling:
1922 ret = devm_request_threaded_irq(&pdev->dev, irq, dcmi_irq_callback, 1923 dcmi_irq_thread, IRQF_ONESHOT, 1924 dev_name(&pdev->dev), dcmi);
there is still uninitialized field sd_format of struct stm32_dcmi *dcmi. If an interrupt occurs in the interval between the installation of the interrupt handler and the initialization of this field, NULL pointer dereference happens.
This field is dereferenced in the handler function without any check:
457 if (dcmi->sd_format->fourcc == V4L2_PIX_FMT_JPEG && 458 dcmi->misr & IT_FRAME) {
The patch moves interrupt handler installation after initialization of the sd_format field that happens in dcmi_graph_notify_complete() via dcmi_set_default_fmt().
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Dmitriy Ulitin ulitin@ispras.ru Signed-off-by: Alexey Khoroshilov khoroshilov@ispras.ru Signed-off-by: Sakari Ailus sakari.ailus@linux.intel.com Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/media/platform/stm32/stm32-dcmi.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-)
diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c index d41475f56ab54..72798aae7a628 100644 --- a/drivers/media/platform/stm32/stm32-dcmi.c +++ b/drivers/media/platform/stm32/stm32-dcmi.c @@ -135,6 +135,7 @@ struct stm32_dcmi { int sequence; struct list_head buffers; struct dcmi_buf *active; + int irq;
struct v4l2_device v4l2_dev; struct video_device *vdev; @@ -1720,6 +1721,14 @@ static int dcmi_graph_notify_complete(struct v4l2_async_notifier *notifier) return ret; }
+ ret = devm_request_threaded_irq(dcmi->dev, dcmi->irq, dcmi_irq_callback, + dcmi_irq_thread, IRQF_ONESHOT, + dev_name(dcmi->dev), dcmi); + if (ret) { + dev_err(dcmi->dev, "Unable to request irq %d\n", dcmi->irq); + return ret; + } + return 0; }
@@ -1881,6 +1890,8 @@ static int dcmi_probe(struct platform_device *pdev) if (irq <= 0) return irq ? irq : -ENXIO;
+ dcmi->irq = irq; + dcmi->res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!dcmi->res) { dev_err(&pdev->dev, "Could not get resource\n"); @@ -1893,14 +1904,6 @@ static int dcmi_probe(struct platform_device *pdev) return PTR_ERR(dcmi->regs); }
- ret = devm_request_threaded_irq(&pdev->dev, irq, dcmi_irq_callback, - dcmi_irq_thread, IRQF_ONESHOT, - dev_name(&pdev->dev), dcmi); - if (ret) { - dev_err(&pdev->dev, "Unable to request irq %d\n", irq); - return ret; - } - mclk = devm_clk_get(&pdev->dev, "mclk"); if (IS_ERR(mclk)) { if (PTR_ERR(mclk) != -EPROBE_DEFER)