This is an effort to get rid of all multiplications from allocation
functions in order to prevent integer overflows [1].
As the cpu variable is a pointer to "struct bcm6345_l1_cpu" and this
structure ends in a flexible array:
struct bcm6345_l1_cpu {
[...]
u32 enable_cache[];
};
the preferred way in the kernel is to use the struct_size() helper to
do the arithmetic instead of the argument "size + count * size" in the
kzalloc() function.
This way, the code is more readable and more safer.
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
Link: https://github.com/KSPP/linux/issues/162 [2]
Signed-off-by: Erick Archer <[email protected]>
---
drivers/irqchip/irq-bcm6345-l1.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/irqchip/irq-bcm6345-l1.c b/drivers/irqchip/irq-bcm6345-l1.c
index 9745a119d0e6..eb02d203c963 100644
--- a/drivers/irqchip/irq-bcm6345-l1.c
+++ b/drivers/irqchip/irq-bcm6345-l1.c
@@ -242,7 +242,7 @@ static int __init bcm6345_l1_init_one(struct device_node *dn,
else if (intc->n_words != n_words)
return -EINVAL;
- cpu = intc->cpus[idx] = kzalloc(sizeof(*cpu) + n_words * sizeof(u32),
+ cpu = intc->cpus[idx] = kzalloc(struct_size(cpu, enable_cache, n_words),
GFP_KERNEL);
if (!cpu)
return -ENOMEM;
--
2.25.1
On Fri, Feb 09, 2024 at 07:16:00PM +0100, Erick Archer wrote:
> This is an effort to get rid of all multiplications from allocation
> functions in order to prevent integer overflows [1].
>
> As the cpu variable is a pointer to "struct bcm6345_l1_cpu" and this
> structure ends in a flexible array:
>
> struct bcm6345_l1_cpu {
> [...]
> u32 enable_cache[];
> };
>
> the preferred way in the kernel is to use the struct_size() helper to
> do the arithmetic instead of the argument "size + count * size" in the
> kzalloc() function.
>
> This way, the code is more readable and more safer.
>
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
> Link: https://github.com/KSPP/linux/issues/162 [2]
> Signed-off-by: Erick Archer <[email protected]>
Thanks!
Reviewed-by: Kees Cook <[email protected]>
--
Kees Cook
On 2/9/2024 10:16 AM, Erick Archer wrote:
> This is an effort to get rid of all multiplications from allocation
> functions in order to prevent integer overflows [1].
>
> As the cpu variable is a pointer to "struct bcm6345_l1_cpu" and this
> structure ends in a flexible array:
>
> struct bcm6345_l1_cpu {
> [...]
> u32 enable_cache[];
> };
>
> the preferred way in the kernel is to use the struct_size() helper to
> do the arithmetic instead of the argument "size + count * size" in the
> kzalloc() function.
>
> This way, the code is more readable and more safer.
>
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
> Link: https://github.com/KSPP/linux/issues/162 [2]
> Signed-off-by: Erick Archer <[email protected]>
Reviewed-by: Florian Fainelli <[email protected]>
--
Florian
The following commit has been merged into the irq/core branch of tip:
Commit-ID: 004c7a6bf43edbd4b092fb6ebba8991d56bc3428
Gitweb: https://git.kernel.org/tip/004c7a6bf43edbd4b092fb6ebba8991d56bc3428
Author: Erick Archer <[email protected]>
AuthorDate: Fri, 09 Feb 2024 19:16:00 +01:00
Committer: Thomas Gleixner <[email protected]>
CommitterDate: Tue, 13 Feb 2024 10:53:15 +01:00
irqchip/bcm-6345-l1: Prefer struct_size)_ over open coded arithmetic
This is an effort to get rid of all multiplications from allocation
functions in order to prevent integer overflows.
The cpu variable is a pointer to "struct bcm6345_l1_cpu" and this structure
ends in a flexible array:
struct bcm6345_l1_cpu {
[...]
u32 enable_cache[];
};
The preferred way in the kernel is to use the struct_size() helper to do
the arithmetic instead of the argument "size + count * size" in the
kzalloc() function.
This way, the code is more readable and safer.
Signed-off-by: Erick Archer <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Gustavo A. R. Silva <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Florian Fainelli <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
Link: https://github.com/KSPP/linux/issues/162 [2]
---
drivers/irqchip/irq-bcm6345-l1.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/irqchip/irq-bcm6345-l1.c b/drivers/irqchip/irq-bcm6345-l1.c
index 9745a11..eb02d20 100644
--- a/drivers/irqchip/irq-bcm6345-l1.c
+++ b/drivers/irqchip/irq-bcm6345-l1.c
@@ -242,7 +242,7 @@ static int __init bcm6345_l1_init_one(struct device_node *dn,
else if (intc->n_words != n_words)
return -EINVAL;
- cpu = intc->cpus[idx] = kzalloc(sizeof(*cpu) + n_words * sizeof(u32),
+ cpu = intc->cpus[idx] = kzalloc(struct_size(cpu, enable_cache, n_words),
GFP_KERNEL);
if (!cpu)
return -ENOMEM;