[PATCH v2 net] ptp: fix integer overflow in max_vclocks_store

[PATCH v2 net] ptp: fix integer overflow in max_vclocks_store

[Dan Carpenter]

On 32bit systems, the "4 * max" multiply can overflow.  Use kcalloc()
to do the allocation to prevent this.

Fixes: 44c494c8e30e ("ptp: track available ptp vclocks information")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
v2: It's better to use kcalloc() instead of size_mul().

 drivers/ptp/ptp_sysfs.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/ptp/ptp_sysfs.c b/drivers/ptp/ptp_sysfs.c
index a15460aaa03b..6b1b8f57cd95 100644
--- a/drivers/ptp/ptp_sysfs.c
+++ b/drivers/ptp/ptp_sysfs.c
@@ -296,8 +296,7 @@ static ssize_t max_vclocks_store(struct device *dev,
 	if (max < ptp->n_vclocks)
 		goto out;
 
-	size = sizeof(int) * max;
-	vclock_index = kzalloc(size, GFP_KERNEL);
+	vclock_index = kcalloc(max, sizeof(int), GFP_KERNEL);
 	if (!vclock_index) {
 		err = -ENOMEM;
 		goto out;
-- 
2.43.0

Re: [PATCH v2 net] ptp: fix integer overflow in max_vclocks_store

[Wojciech Drewek]

On 17.06.2024 11:34, Dan Carpenter wrote:
> On 32bit systems, the "4 * max" multiply can overflow.  Use kcalloc()
> to do the allocation to prevent this.
> 
> Fixes: 44c494c8e30e ("ptp: track available ptp vclocks information")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---

Thx,
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>

> v2: It's better to use kcalloc() instead of size_mul().
> 
>  drivers/ptp/ptp_sysfs.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/ptp/ptp_sysfs.c b/drivers/ptp/ptp_sysfs.c
> index a15460aaa03b..6b1b8f57cd95 100644
> --- a/drivers/ptp/ptp_sysfs.c
> +++ b/drivers/ptp/ptp_sysfs.c
> @@ -296,8 +296,7 @@ static ssize_t max_vclocks_store(struct device *dev,
>  	if (max < ptp->n_vclocks)
>  		goto out;
>  
> -	size = sizeof(int) * max;
> -	vclock_index = kzalloc(size, GFP_KERNEL);
> +	vclock_index = kcalloc(max, sizeof(int), GFP_KERNEL);
>  	if (!vclock_index) {
>  		err = -ENOMEM;
>  		goto out;

Re: [PATCH v2 net] ptp: fix integer overflow in max_vclocks_store

[Jiri Pirko]

Mon, Jun 17, 2024 at 11:34:32AM CEST, dan.carpenter@linaro.org wrote:
>On 32bit systems, the "4 * max" multiply can overflow.  Use kcalloc()
>to do the allocation to prevent this.
>
>Fixes: 44c494c8e30e ("ptp: track available ptp vclocks information")
>Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>

Reviewed-by: Jiri Pirko <jiri@nvidia.com>

Re: [PATCH v2 net] ptp: fix integer overflow in max_vclocks_store

[Heng Qi]

在 2024/6/17 下午5:34, Dan Carpenter 写道:
> On 32bit systems, the "4 * max" multiply can overflow.  Use kcalloc()
> to do the allocation to prevent this.
>
> Fixes: 44c494c8e30e ("ptp: track available ptp vclocks information")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
> v2: It's better to use kcalloc() instead of size_mul().
>
>   drivers/ptp/ptp_sysfs.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/ptp/ptp_sysfs.c b/drivers/ptp/ptp_sysfs.c
> index a15460aaa03b..6b1b8f57cd95 100644
> --- a/drivers/ptp/ptp_sysfs.c
> +++ b/drivers/ptp/ptp_sysfs.c
> @@ -296,8 +296,7 @@ static ssize_t max_vclocks_store(struct device *dev,
>   	if (max < ptp->n_vclocks)
>   		goto out;
>   
> -	size = sizeof(int) * max;
> -	vclock_index = kzalloc(size, GFP_KERNEL);
> +	vclock_index = kcalloc(max, sizeof(int), GFP_KERNEL);
>   	if (!vclock_index) {
>   		err = -ENOMEM;
>   		goto out;

Reviewed-by: Heng Qi <hengqi@linux.alibaba.com>

Thanks!

Re: [PATCH v2 net] ptp: fix integer overflow in max_vclocks_store

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Mon, 17 Jun 2024 12:34:32 +0300 you wrote:
> On 32bit systems, the "4 * max" multiply can overflow.  Use kcalloc()
> to do the allocation to prevent this.
> 
> Fixes: 44c494c8e30e ("ptp: track available ptp vclocks information")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
> v2: It's better to use kcalloc() instead of size_mul().
> 
> [...]

Here is the summary with links:
  - [v2,net] ptp: fix integer overflow in max_vclocks_store
    https://git.kernel.org/netdev/net/c/81d23d2a2401

You are awesome, thank you!
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