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[1/6] Convert virtio_console to struct_size

Message ID 20180607145720.22590-2-willy@infradead.org (mailing list archive)
State New, archived
Headers show

Commit Message

Matthew Wilcox June 7, 2018, 2:57 p.m. UTC 
From: Matthew Wilcox <mawilcox@microsoft.com>

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
 drivers/char/virtio_console.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

Comments

Kees Cook June 7, 2018, 7:29 p.m. UTC | #1 
On Thu, Jun 7, 2018 at 7:57 AM, Matthew Wilcox <willy@infradead.org> wrote:
> From: Matthew Wilcox <mawilcox@microsoft.com>
>
> Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
> ---
>  drivers/char/virtio_console.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
> index 21085515814f..4bf7c06c2343 100644
> --- a/drivers/char/virtio_console.c
> +++ b/drivers/char/virtio_console.c
> @@ -433,8 +433,7 @@ static struct port_buffer *alloc_buf(struct virtio_device *vdev, size_t buf_size
>          * Allocate buffer and the sg list. The sg list array is allocated
>          * directly after the port_buffer struct.
>          */
> -       buf = kmalloc(sizeof(*buf) + sizeof(struct scatterlist) * pages,
> -                     GFP_KERNEL);
> +       buf = kmalloc(struct_size(buf, sg, pages), GFP_KERNEL);
>         if (!buf)
>                 goto fail;

I feel like this one should have been caught by Coccinelle... maybe
the transitive case got missed? Regardless, I'll figure out how to
improve the script and/or take these.

Thanks!

-Kees
Kees Cook June 7, 2018, 8:43 p.m. UTC | #2 
On Thu, Jun 7, 2018 at 12:29 PM, Kees Cook <keescook@chromium.org> wrote:
> On Thu, Jun 7, 2018 at 7:57 AM, Matthew Wilcox <willy@infradead.org> wrote:
>> From: Matthew Wilcox <mawilcox@microsoft.com>
>>
>> Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
>> ---
>>  drivers/char/virtio_console.c | 3 +--
>>  1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
>> index 21085515814f..4bf7c06c2343 100644
>> --- a/drivers/char/virtio_console.c
>> +++ b/drivers/char/virtio_console.c
>> @@ -433,8 +433,7 @@ static struct port_buffer *alloc_buf(struct virtio_device *vdev, size_t buf_size
>>          * Allocate buffer and the sg list. The sg list array is allocated
>>          * directly after the port_buffer struct.
>>          */
>> -       buf = kmalloc(sizeof(*buf) + sizeof(struct scatterlist) * pages,
>> -                     GFP_KERNEL);
>> +       buf = kmalloc(struct_size(buf, sg, pages), GFP_KERNEL);
>>         if (!buf)
>>                 goto fail;
>
> I feel like this one should have been caught by Coccinelle... maybe
> the transitive case got missed? Regardless, I'll figure out how to
> improve the script and/or take these.

Oh, duh. Got it: "struct scatterlist" is not an expression, it's a
type. I'll adjust the script, catch stragglers, and incorporate your
patches. :)

Thanks!

-Kees
diff mbox

Patch

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 21085515814f..4bf7c06c2343 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -433,8 +433,7 @@  static struct port_buffer *alloc_buf(struct virtio_device *vdev, size_t buf_size
 	 * Allocate buffer and the sg list. The sg list array is allocated
 	 * directly after the port_buffer struct.
 	 */
-	buf = kmalloc(sizeof(*buf) + sizeof(struct scatterlist) * pages,
-		      GFP_KERNEL);
+	buf = kmalloc(struct_size(buf, sg, pages), GFP_KERNEL);
 	if (!buf)
 		goto fail;