On Thu, 2023-07-20 at 23:53 +0300, Andy Shevchenko wrote:
> Let the krealloc_array() copy the original data and
> check for a multiplication overflow.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
> drivers/iio/industrialio-core.c | 20 +++++++-------------
> 1 file changed, 7 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index 90e59223b178..be154879983e 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -1465,7 +1465,7 @@ int iio_device_register_sysfs_group(struct iio_dev
> *indio_dev,
> const struct attribute_group **new, **old = iio_dev_opaque->groups;
> unsigned int cnt = iio_dev_opaque->groupcounter;
>
> - new = krealloc(old, sizeof(*new) * (cnt + 2), GFP_KERNEL);
> + new = krealloc_array(old, cnt + 2, sizeof(*new), GFP_KERNEL);
> if (!new)
> return -ENOMEM;
>
> @@ -1483,13 +1483,13 @@ static int iio_device_register_sysfs(struct iio_dev
> *indio_dev)
> {
> struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
> int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
> + struct attribute **attrs, **attr, *clk = NULL;
> struct iio_dev_attr *p;
> - struct attribute **attr, *clk = NULL;
>
> /* First count elements in any existing group */
> - if (indio_dev->info->attrs) {
> - attr = indio_dev->info->attrs->attrs;
> - while (*attr++ != NULL)
> + attrs = indio_dev->info->attrs ? indio_dev->info->attrs->attrs : NULL;
> + if (attrs) {
> + for (attr = attrs; *attr; attr++)
> attrcount_orig++;
not really related with the change... maybe just mention it in the commit?
> }
> attrcount = attrcount_orig;
> @@ -1521,20 +1521,14 @@ static int iio_device_register_sysfs(struct iio_dev
> *indio_dev)
> if (clk)
> attrcount++;
>
> + /* Copy across original attributes, and point to original binary
> attributes */
> iio_dev_opaque->chan_attr_group.attrs =
> - kcalloc(attrcount + 1,
> - sizeof(iio_dev_opaque->chan_attr_group.attrs[0]),
> - GFP_KERNEL);
> + krealloc_array(attrs, attrcount + 1, sizeof(*attrs),
> GFP_KERNEL);
> if (iio_dev_opaque->chan_attr_group.attrs == NULL) {
since you're here and you also already did some style cleanups above, maybe
change it to 'if (!iio_dev_opaque->chan_attr_group.attrs)'?
- Nuno Sá
