[PATCH 4/5] drivers/media/video/atmel-isi.c: eliminate a null pointer dereference

From: Julia Lawall
Date: Fri Oct 28 2011 - 19:59:13 EST


From: Julia Lawall <julia@xxxxxxx>

The variable isi might be null or might be freed at the point of the call
to clk_put. pclk contains the value that isi->pclk is expected to point to.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
expression E, E1;
identifier f;
statement S1,S2,S3;
@@

if (E == NULL)
{
... when != if (E == NULL || ...) S1 else S2
when != E = E1
*E->f
... when any
return ...;
}
else S3
// </smpl>

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

---
drivers/media/video/atmel-isi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/video/atmel-isi.c b/drivers/media/video/atmel-isi.c
index 774715d..a3dafd6 100644
--- a/drivers/media/video/atmel-isi.c
+++ b/drivers/media/video/atmel-isi.c
@@ -1026,7 +1026,7 @@ err_alloc_ctx:
err_alloc_descriptors:
kfree(isi);
err_alloc_isi:
- clk_put(isi->pclk);
+ clk_put(pclk);

return ret;
}

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