On Sun, Aug 26, 2018 at 11:47 AM, Gustavo A. R. Silva gustavo@embeddedor.com wrote:
One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example:
struct foo { int stuff; void *entry[]; };
instance = devm_kzalloc(dev, sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);
or, like in this particular case:
size = sizeof(struct foo) + sizeof(void *) * count; instance = devm_kzalloc(dev, size, GFP_KERNEL);
Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper:
instance = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL);
This issue was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva gustavo@embeddedor.com
Reviewed-by: Kees Cook keescook@chromium.org
-Kees
drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c index 1359e5c..cf64e4d 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c @@ -32,6 +32,7 @@ #include <linux/of_device.h> #include <linux/pm_runtime.h> #include <linux/component.h> +#include <linux/overflow.h>
#include <linux/reset.h> #include <linux/delay.h> @@ -1561,7 +1562,6 @@ static int vop_bind(struct device *dev, struct device *master, void *data) struct drm_device *drm_dev = data; struct vop *vop; struct resource *res;
size_t alloc_size; int ret, irq; vop_data = of_device_get_match_data(dev);@@ -1569,8 +1569,8 @@ static int vop_bind(struct device *dev, struct device *master, void *data) return -ENODEV;
/* Allocate vop struct and its vop_win array */
alloc_size = sizeof(*vop) + sizeof(*vop->win) * vop_data->win_size;vop = devm_kzalloc(dev, alloc_size, GFP_KERNEL);
vop = devm_kzalloc(dev, struct_size(vop, win, vop_data->win_size),GFP_KERNEL); if (!vop) return -ENOMEM;-- 2.7.4