[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:
(http://coccinelle.lip6.fr/)
// <smpl>
@fn exists@
expression list es;
expression a,b;
identifier f;
@@
if (...) {
... when any
free_irq(a,b);
... when any
f(es);
... when any
return ...;
}
@@
expression list fn.es;
expression fn.a,fn.b;
identifier fn.f;
@@
*f(es);
... when any
*free_irq(a,b);
// </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)
clk_put(pcdev->clk);
+ free_irq(pcdev->irq, pcdev);
pxa_free_dma(pcdev->dma_chans[0]);
pxa_free_dma(pcdev->dma_chans[1]);
pxa_free_dma(pcdev->dma_chans[2]);
- free_irq(pcdev->irq, pcdev);
soc_camera_host_unregister(soc_host);
--
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