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From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
To: Will Deacon <will@kernel.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Joerg Roedel <joro@8bytes.org>
Cc: linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org,
	Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
	linux-arm-kernel@lists.infradead.org,
	iommu@lists.linux-foundation.org
Subject: [PATCH v2 1/2] iommu/arm-smmu-v3: Avoid open coded arithmetic in memory allocation
Date: Mon,  7 Feb 2022 23:50:48 +0100	[thread overview]
Message-ID: <3f7b9b202c6b6f5edc234ab7af5f208fbf8bc944.1644274051.git.christophe.jaillet@wanadoo.fr> (raw)

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@wanadoo.fr>
Acked-by: Robin Murphy <robin.murphy@arm.com>
---
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


WARNING: multiple messages have this Message-ID (diff)
From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
To: Will Deacon <will@kernel.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Joerg Roedel <joro@8bytes.org>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
	iommu@lists.linux-foundation.org,
	kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 1/2] iommu/arm-smmu-v3: Avoid open coded arithmetic in memory allocation
Date: Mon,  7 Feb 2022 23:50:48 +0100	[thread overview]
Message-ID: <3f7b9b202c6b6f5edc234ab7af5f208fbf8bc944.1644274051.git.christophe.jaillet@wanadoo.fr> (raw)

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@wanadoo.fr>
Acked-by: Robin Murphy <robin.murphy@arm.com>
---
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

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

WARNING: multiple messages have this Message-ID (diff)
From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
To: Will Deacon <will@kernel.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Joerg Roedel <joro@8bytes.org>
Cc: linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org,
	Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
	linux-arm-kernel@lists.infradead.org,
	iommu@lists.linux-foundation.org
Subject: [PATCH v2 1/2] iommu/arm-smmu-v3: Avoid open coded arithmetic in memory allocation
Date: Mon,  7 Feb 2022 23:50:48 +0100	[thread overview]
Message-ID: <3f7b9b202c6b6f5edc234ab7af5f208fbf8bc944.1644274051.git.christophe.jaillet@wanadoo.fr> (raw)

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@wanadoo.fr>
Acked-by: Robin Murphy <robin.murphy@arm.com>
---
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


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

             reply	other threads:[~2022-02-07 22:50 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-07 22:50 Christophe JAILLET [this message]
2022-02-07 22:50 ` [PATCH v2 1/2] iommu/arm-smmu-v3: Avoid open coded arithmetic in memory allocation Christophe JAILLET
2022-02-07 22:50 ` Christophe JAILLET
2022-02-07 22:47 ` [PATCH v2 2/2] iommu/arm-smmu-v3: Simplify " Christophe JAILLET
2022-02-07 22:47   ` Christophe JAILLET
2022-02-07 22:47   ` Christophe JAILLET
2022-02-08 16:21 ` [PATCH v2 1/2] iommu/arm-smmu-v3: Avoid open coded arithmetic in " Will Deacon
2022-02-08 16:21   ` Will Deacon
2022-02-08 16:21   ` Will Deacon

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