2022-04-25 18:27:05

by Yang Yingliang

Subject: [PATCH] iommu/dart: check return value after calling platform_get_resource()

It will cause null-ptr-deref in resource_size(), if platform_get_resource()
returns NULL, move calling resource_size() after devm_ioremap_resource() that
will check 'res' to avoid null-ptr-deref.
And use devm_platform_get_and_ioremap_resource() to simplify code.

Fixes: 46d1fb072e76 ("iommu/dart: Add DART iommu driver")
Signed-off-by: Yang Yingliang <[email protected]>
---
drivers/iommu/apple-dart.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c
index decafb07ad08..15b77f16cfa3 100644
--- a/drivers/iommu/apple-dart.c
+++ b/drivers/iommu/apple-dart.c
@@ -859,16 +859,15 @@ static int apple_dart_probe(struct platform_device *pdev)
dart->dev = dev;
spin_lock_init(&dart->lock);

- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ dart->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+ if (IS_ERR(dart->regs))
+ return PTR_ERR(dart->regs);
+
if (resource_size(res) < 0x4000) {
dev_err(dev, "MMIO region too small (%pr)\n", res);
return -EINVAL;
}

- dart->regs = devm_ioremap_resource(dev, res);
- if (IS_ERR(dart->regs))
- return PTR_ERR(dart->regs);
-
dart->irq = platform_get_irq(pdev, 0);
if (dart->irq < 0)
return -ENODEV;
--
2.25.1

2022-04-27 11:24:54

by Sven Peter

Subject: Re: [PATCH] iommu/dart: check return value after calling platform_get_resource()

> On 25. Apr 2022, at 10:56, Yang Yingliang <[email protected]> wrote:
>
> It will cause null-ptr-deref in resource_size(), if platform_get_resource()
> returns NULL, move calling resource_size() after devm_ioremap_resource() that
> will check 'res' to avoid null-ptr-deref.
> And use devm_platform_get_and_ioremap_resource() to simplify code.
>
> Fixes: 46d1fb072e76 ("iommu/dart: Add DART iommu driver")
> Signed-off-by: Yang Yingliang <[email protected]>

Reviewed-by: Sven Peter <[email protected]>


Thanks,

Sven

2022-04-28 10:49:44

by Joerg Roedel

Subject: Re: [PATCH] iommu/dart: check return value after calling platform_get_resource()

On Mon, Apr 25, 2022 at 05:08:26PM +0800, Yang Yingliang wrote:
> It will cause null-ptr-deref in resource_size(), if platform_get_resource()
> returns NULL, move calling resource_size() after devm_ioremap_resource() that
> will check 'res' to avoid null-ptr-deref.
> And use devm_platform_get_and_ioremap_resource() to simplify code.
>
> Fixes: 46d1fb072e76 ("iommu/dart: Add DART iommu driver")
> Signed-off-by: Yang Yingliang <[email protected]>
> ---
> drivers/iommu/apple-dart.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)

Applied to iommu/fixes, thanks.