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 fw_rsc_vdev {
...
struct fw_rsc_vdev_vring vring[0];
} __packed;
Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.
So, replace the following form:
sizeof(*rsc) + rsc->num_of_vrings * sizeof(struct fw_rsc_vdev_vring)
with:
struct_size(rsc, vring, rsc->num_of_vrings)
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20190830151406.GA23274@embeddedor
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
char name[16];
/* make sure resource isn't truncated */
- if (sizeof(*rsc) + rsc->num_of_vrings * sizeof(struct fw_rsc_vdev_vring)
- + rsc->config_len > avail) {
+ if (struct_size(rsc, vring, rsc->num_of_vrings) + rsc->config_len >
+ avail) {
dev_err(dev, "vdev rsc is truncated\n");
return -EINVAL;
}