[PATCH v2 1/2] iommu/arm-smmu-v3: Avoid open coded arithmetic in memory allocation

From: Christophe JAILLET
Date: Mon Feb 07 2022 - 17:50:55 EST


kmalloc_array()/kcalloc() should be used to avoid potential overflow when
a multiplication is needed to compute the size of the requested memory.

So turn a devm_kzalloc()+explicit size computation into an equivalent
devm_kcalloc().

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
Acked-by: Robin Murphy <robin.murphy@xxxxxxx>
---
This is NOT compile tested.
I don't have the needed cross compiling tools.

v2: - no changes
- Acked-by added
---
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 6dc6d8b6b368..14d06aad0726 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2981,10 +2981,10 @@ static int arm_smmu_init_l1_strtab(struct arm_smmu_device *smmu)
{
unsigned int i;
struct arm_smmu_strtab_cfg *cfg = &smmu->strtab_cfg;
- size_t size = sizeof(*cfg->l1_desc) * cfg->num_l1_ents;
void *strtab = smmu->strtab_cfg.strtab;

- cfg->l1_desc = devm_kzalloc(smmu->dev, size, GFP_KERNEL);
+ cfg->l1_desc = devm_kcalloc(smmu->dev, cfg->num_l1_ents,
+ sizeof(*cfg->l1_desc), GFP_KERNEL);
if (!cfg->l1_desc)
return -ENOMEM;

--
2.32.0