Commit 69508d43 authored by Gustavo A. R. Silva's avatar Gustavo A. R. Silva Committed by Jakub Kicinski
Browse files

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: default avatarGustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20210928193107.GA262595@embeddedor


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent ef91abfb

net/sched/sch_api.c

+4 −3
Original line number Diff line number Diff line
@@ -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);