[PATCH] Staging: iommu: Replace null pointer check with IS_ERR in arm_smmu_domain_alloc_user()
Pranjal Shrivastava
praan at google.com
Sun Sep 22 20:10:08 PDT 2024
On Sun, Sep 22, 2024 at 03:56:20PM +0000, Dipendra Khadka wrote:
> The smatch reported following:
> '''
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c:3065 arm_smmu_domain_alloc_user() warn: 'smmu_domain' is an error pointer or valid
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c:3068 arm_smmu_domain_alloc_user() error: 'smmu_domain' dereferencing possible ERR_PTR()
> '''
>
> The function arm_smmu_domain_alloc() handles the null pointer after
> kzalloc and returns ERR_PTR(-ENOMEM).
>
> Replacing condition check !smmu_domain with IS_ERR(smmu_domain) and
> returning smmu_domain.
Hi Dipendra,
Thanks for looking into the code. However, I think this was fixed last
month by Dan's patch [1] and has been merged in the master branch.
Please pull the latest. :)
[1]
https://lore.kernel.org/linux-arm-kernel/172381875518.1794999.1134549433569030700.b4-ty@kernel.org/T/
>
> Signed-off-by: Dipendra Khadka <kdipendra88 at gmail.com>
> ---
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index a31460f9f3d4..19c53c6f7578 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -3062,8 +3062,8 @@ arm_smmu_domain_alloc_user(struct device *dev, u32 flags,
> return ERR_PTR(-EOPNOTSUPP);
>
> smmu_domain = arm_smmu_domain_alloc();
> - if (!smmu_domain)
> - return ERR_PTR(-ENOMEM);
> + if (IS_ERR(smmu_domain))
> + return smmu_domain;
Quick note, using something like `ERR_CAST` is better in such cases.
>
> smmu_domain->domain.type = IOMMU_DOMAIN_UNMANAGED;
> smmu_domain->domain.ops = arm_smmu_ops.default_domain_ops;
> --
> 2.43.0
>
>
Thanks,
Pranjal
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