net_sched: Use struct_size() and flex_array_size() helpers

Make use of the struct_size() and flex_array_size() helpers instead of
an open-coded version, in order to avoid any potential type mistakes
or integer overflows that, in the worse scenario, could lead to heap
overflows.

Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20210928193107.GA262595@embeddedor
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Gustavo A. R. Silva 2021-09-28 14:31:07 -05:00 committed by Jakub Kicinski
parent ef91abfb20
commit 69508d4333

View File

@ -507,20 +507,21 @@ static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt,
list_for_each_entry(stab, &qdisc_stab_list, list) {
if (memcmp(&stab->szopts, s, sizeof(*s)))
continue;
if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
if (tsize > 0 &&
memcmp(stab->data, tab, flex_array_size(stab, data, tsize)))
continue;
stab->refcnt++;
return stab;
}
stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
stab = kmalloc(struct_size(stab, data, tsize), GFP_KERNEL);
if (!stab)
return ERR_PTR(-ENOMEM);
stab->refcnt = 1;
stab->szopts = *s;
if (tsize > 0)
memcpy(stab->data, tab, tsize * sizeof(u16));
memcpy(stab->data, tab, flex_array_size(stab, data, tsize));
list_add_tail(&stab->list, &qdisc_stab_list);