[PATCH] drivers/usb: misc: use kmalloc_array() instead of kmalloc() to prevent overflow

[PATCH] drivers/usb: misc: use kmalloc_array() instead of kmalloc() to prevent overflow

[jindongyang]

Documentation/process/deprecated.rst recommends against the use of
kmalloc with dynamic size calculations due to the risk of overflow.

Replace kmalloc() with kmalloc_array() in adutux.c to make the
intended allocation size clearer and avoid potential overflow issues.

No functional change intended.

Signed-off-by: jindongyang <jindongyang@kylinos.cn>
---
 drivers/usb/misc/adutux.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/misc/adutux.c b/drivers/usb/misc/adutux.c
index ed6a19254d2f..000a3ade7432 100644
--- a/drivers/usb/misc/adutux.c
+++ b/drivers/usb/misc/adutux.c
@@ -680,7 +680,7 @@ static int adu_probe(struct usb_interface *interface,
 	in_end_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
 	out_end_size = usb_endpoint_maxp(dev->interrupt_out_endpoint);
 
-	dev->read_buffer_primary = kmalloc((4 * in_end_size), GFP_KERNEL);
+	dev->read_buffer_primary = kmalloc_array(4, in_end_size, GFP_KERNEL);
 	if (!dev->read_buffer_primary)
 		goto error;
 
@@ -690,7 +690,7 @@ static int adu_probe(struct usb_interface *interface,
 	memset(dev->read_buffer_primary + (2 * in_end_size), 'c', in_end_size);
 	memset(dev->read_buffer_primary + (3 * in_end_size), 'd', in_end_size);
 
-	dev->read_buffer_secondary = kmalloc((4 * in_end_size), GFP_KERNEL);
+	dev->read_buffer_secondary = kmalloc_array(4, in_end_size, GFP_KERNEL);
 	if (!dev->read_buffer_secondary)
 		goto error;
 
-- 
2.25.1

Re: [PATCH] drivers/usb: misc: use kmalloc_array() instead of kmalloc() to prevent overflow

[Greg KH]

On Thu, Jan 29, 2026 at 05:32:02PM +0800, jindongyang wrote:
> Documentation/process/deprecated.rst recommends against the use of
> kmalloc with dynamic size calculations due to the risk of overflow.
> 
> Replace kmalloc() with kmalloc_array() in adutux.c to make the
> intended allocation size clearer and avoid potential overflow issues.
> 
> No functional change intended.
> 
> Signed-off-by: jindongyang <jindongyang@kylinos.cn>

We need a name here, not an email alias.

> ---
>  drivers/usb/misc/adutux.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/misc/adutux.c b/drivers/usb/misc/adutux.c
> index ed6a19254d2f..000a3ade7432 100644
> --- a/drivers/usb/misc/adutux.c
> +++ b/drivers/usb/misc/adutux.c
> @@ -680,7 +680,7 @@ static int adu_probe(struct usb_interface *interface,
>  	in_end_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
>  	out_end_size = usb_endpoint_maxp(dev->interrupt_out_endpoint);
>  
> -	dev->read_buffer_primary = kmalloc((4 * in_end_size), GFP_KERNEL);
> +	dev->read_buffer_primary = kmalloc_array(4, in_end_size, GFP_KERNEL);

This really doesn't do anything, as there can't be an overflow, right?
So please don't imply that there is in the changelog and subject line.

This is just a "janitorial" patch that does not do anything different.
So there is not really a need for it that I can determine, correct?

thanks,

greg k-h