Re: [PATCH 13/15] drivers/usb/musb/omap2430.c: adjust duplicate test

From: Felipe Balbi
Date: Mon Jan 21 2013 - 07:28:19 EST


Hi,

On Mon, Jan 21, 2013 at 02:02:57PM +0100, Julia Lawall wrote:
> From: Julia Lawall <Julia.Lawall@xxxxxxx>
>
> Delete successive tests to the same location. Data is the just previously
> allocated and tested value. Test the result of the allocation made here
> instead.
>
> A simplified version of the semantic match that finds this problem is as
> follows: (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @s exists@
> local idexpression y;
> expression x,e;
> @@
>
> *if ( \(x == NULL\|IS_ERR(x)\|y != 0\) )
> { ... when forall
> return ...; }
> ... when != \(y = e\|y += e\|y -= e\|y |= e\|y &= e\|y++\|y--\|&y\)
> when != \(XT_GETPAGE(...,y)\|WMI_CMD_BUF(...)\)
> *if ( \(x == NULL\|IS_ERR(x)\|y != 0\) )
> { ... when forall
> return ...; }
> // </smpl>
>
> Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxx>

Already in my tree ;-)

commit b37457d80bc3e2a6bb86a6036c572574614a7631
Author: Sergei Shtylyov <sshtylyov@xxxxxxxxxxxxx>
Date: Tue Jan 8 22:11:14 2013 +0300

usb: musb: omap2430: fix wrong devm_kzalloc() result check

Commit 00a0b1d58af873d842580dcac55f3b156c3a4077 (usb: musb: omap: Add device
tree support for omap musb glue) assigns result of devm_kzalloc() call to
the 'config' variable but then checks for NULL the 'data' variable (already
checked after previous call). Thus we risk a kernel oops further when data
pointed by 'config' is written to by subsequent of_property_read_u32() calls
iff the allocation happens to fail...

Signed-off-by: Sergei Shtylyov <sshtylyov@xxxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>

diff --git a/drivers/usb/musb/omap2430.c b/drivers/usb/musb/omap2430.c
index b15bb05..bb48796 100644
--- a/drivers/usb/musb/omap2430.c
+++ b/drivers/usb/musb/omap2430.c
@@ -543,7 +543,7 @@ static int omap2430_probe(struct platform_device *pdev)
}

config = devm_kzalloc(&pdev->dev, sizeof(*config), GFP_KERNEL);
- if (!data) {
+ if (!config) {
dev_err(&pdev->dev,
"failed to allocate musb hdrc config\n");
goto err2;

--
balbi

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