[PATCH 1/2] drivers/media/platform/soc_camera/pxa_camera.c: reposition free_irq to avoid access to invalid data

From: Julia Lawall
Date: Mon Jan 07 2013 - 04:00:38 EST

From: Julia Lawall <Julia.Lawall@xxxxxxx>

The data referenced by an interrupt handler should not be freed before the
interrupt is ended. The handler is pxa_camera_irq. This handler may call
pxa_dma_start_channels, which references the channels that are freed on the
lines before the call to free_irq.

The semantic match that finds this problem is as follows:

// <smpl>
@fn exists@
expression list es;
expression a,b;
identifier f;

if (...) {
... when any
... when any
... when any
return ...;

expression list fn.es;
expression fn.a,fn.b;
identifier fn.f;

... when any
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxx>

Not compiled. I have not observed the problem in practice; the code just
looks suspicious.

drivers/media/platform/soc_camera/pxa_camera.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/platform/soc_camera/pxa_camera.c b/drivers/media/platform/soc_camera/pxa_camera.c
index f91f7bf..2a19aba 100644
--- a/drivers/media/platform/soc_camera/pxa_camera.c
+++ b/drivers/media/platform/soc_camera/pxa_camera.c
@@ -1810,10 +1810,10 @@ static int pxa_camera_remove(struct platform_device *pdev)


+ free_irq(pcdev->irq, pcdev);
- free_irq(pcdev->irq, pcdev);


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/