On Mon, 5 Nov 2018 08:58:35 +0100
Boris Brezillon <boris.brezil...@bootlin.com> wrote:
> Enabling -Wvla found another variable-length array with randconfig
> testing:
>
> drivers/mtd/maps/sa1100-flash.c: In function 'sa1100_setup_mtd':
> drivers/mtd/maps/sa1100-flash.c:224:10: error: ISO C90 forbids variable
> length array 'cdev' [-Werror=vla]
>
> Dynamically allocate the cdev array passed to mtd_concat_create()
> instead of using a VLA.
>
> Reported-by: Arnd Bergmann <a...@arndb.de>
> Signed-off-by: Boris Brezillon <boris.brezil...@bootlin.com>
> Cc: Kees Cook <keesc...@chromium.org>
> Cc: Olof Johansson <o...@lixom.net>
Queued to the mtd fixes branch.
> ---
> Changes in v2:
> - Allocate cdev dynamically instead of having a fixed-size array
>
> Hello,
>
> I'm planning to queue this patch to the mtd/fixes PR. Arnd, Kees, feel
> free to add your R-b.
>
> Regards,
>
> Boris
> ---
> drivers/mtd/maps/sa1100-flash.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/maps/sa1100-flash.c b/drivers/mtd/maps/sa1100-flash.c
> index 784c6e1a0391..fd5fe12d7461 100644
> --- a/drivers/mtd/maps/sa1100-flash.c
> +++ b/drivers/mtd/maps/sa1100-flash.c
> @@ -221,7 +221,14 @@ static struct sa_info *sa1100_setup_mtd(struct
> platform_device *pdev,
> info->mtd = info->subdev[0].mtd;
> ret = 0;
> } else if (info->num_subdev > 1) {
> - struct mtd_info *cdev[nr];
> + struct mtd_info **cdev;
> +
> + cdev = kmalloc_array(nr, sizeof(*cdev), GFP_KERNEL);
> + if (!cdev) {
> + ret = -ENOMEM;
> + goto err;
> + }
> +
> /*
> * We detected multiple devices. Concatenate them together.
> */
> @@ -230,6 +237,7 @@ static struct sa_info *sa1100_setup_mtd(struct
> platform_device *pdev,
>
> info->mtd = mtd_concat_create(cdev, info->num_subdev,
> plat->name);
> + kfree(cdev);
> if (info->mtd == NULL) {
> ret = -ENXIO;
> goto err;
