[PATCH] drm/rockchip: Use struct_size() in devm_kzalloc()
From: Kees Cook <hidden>
Date: 2018-08-26 22:08:38
Also in:
dri-devel, linux-rockchip, lkml
On Sun, Aug 26, 2018 at 11:47 AM, Gustavo A. R. Silva [off-list ref] 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 <redacted>Reviewed-by: Kees Cook <redacted> -Kees
quoted hunk ↗ jump to hunk
--- 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
-- Kees Cook Pixel Security