From: Zhouyi Zhou <zhouzho...@gmail.com>
On Tue, 4 Mar 2014 16:41:18 +0100
Joerg Roedel <j...@8bytes.org> wrote:
> On Tue, Feb 11, 2014 at 10:12:53AM +0800, Zhouyi Zhou wrote:
> > From: Zhouyi Zhou <yizhouz...@ict.ac.cn>
> >
> > The function iopte_alloc do not check NULL return of kmem_cache_zalloc,
> > call iopte_free with argument 0 will panic.
> >
> > Signed-off-by: Zhouyi Zhou <yizhouz...@ict.ac.cn>
> > ---
> > drivers/iommu/omap-iommu.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
> > index bcd78a7..5155714 100644
> > --- a/drivers/iommu/omap-iommu.c
> > +++ b/drivers/iommu/omap-iommu.c
> > @@ -551,7 +551,8 @@ static u32 *iopte_alloc(struct omap_iommu *obj, u32
> > *iopgd, u32 da)
> > dev_vdbg(obj->dev, "%s: a new pte:%p\n", __func__, iopte);
> > } else {
> > /* We raced, free the reduniovant table */
> > - iopte_free(iopte);
> > + if (iopte)
> > + iopte_free(iopte);
>
> Isn't it better to put the check into iopte_free?
>
>
> Joerg
>
>
Thanks Joerg for reviewing
Checking the null pointer in iopte_free guarantees kmem_cache_free
is happy all the time.
Signed-off-by: Zhouyi Zhou <yizhouz...@ict.ac.cn>
Signed-off-by: Joerg Roedel <j...@8bytes.org>
---
drivers/iommu/omap-iommu.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index bcd78a7..51211e8 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -523,7 +523,8 @@ static void flush_iopte_range(u32 *first, u32 *last)
static void iopte_free(u32 *iopte)
{
/* Note: freed iopte's must be clean ready for re-use */
- kmem_cache_free(iopte_cachep, iopte);
+ if (iopte)
+ kmem_cache_free(iopte_cachep, iopte);
}
static u32 *iopte_alloc(struct omap_iommu *obj, u32 *iopgd, u32 da)
--
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