Messages in this thread | | | From | Kees Cook <> | Date | Thu, 23 Aug 2018 20:05:06 -0700 | Subject | Re: [PATCH] drivers: qcom: rpmh: use struct_size() in kzalloc() |
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On Thu, Aug 23, 2018 at 6:17 PM, 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 = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_ATOMIC); > > Instead of leaving these open-coded and prone to type mistakes, we can > now use the new struct_size() helper: > > instance = kzalloc(struct_size(instance, entry, count), GFP_ATOMIC); > > 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/soc/qcom/rpmh.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c > index c7beb68..12c057a 100644 > --- a/drivers/soc/qcom/rpmh.c > +++ b/drivers/soc/qcom/rpmh.c > @@ -362,8 +362,7 @@ int rpmh_write_batch(const struct device *dev, enum rpmh_state state, > if (!count) > return -EINVAL; > > - req = kzalloc(sizeof(*req) + count * sizeof(req->rpm_msgs[0]), > - GFP_ATOMIC); > + req = kzalloc(struct_size(req, rpm_msgs, count), GFP_ATOMIC); > if (!req) > return -ENOMEM; > req->count = count; > -- > 2.7.4 >
-- Kees Cook Pixel Security
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