diff mbox series

[next] net_sched: Use struct_size() and flex_array_size() helpers

Message ID 20210927221849.GA188050@embeddedor (mailing list archive)
State Superseded
Headers show
Series [next] net_sched: Use struct_size() and flex_array_size() helpers | expand

Commit Message

Gustavo A. R. Silva Sept. 27, 2021, 10:18 p.m. UTC 
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>
---
 net/sched/sch_api.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

Comments

Jakub Kicinski Sept. 28, 2021, 12:56 a.m. UTC | #1 
On Mon, 27 Sep 2021 17:18:49 -0500 Gustavo A. R. Silva wrote:
> 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>

Does not apply to net-next, please rebase & resend. Thanks!
diff mbox series

Patch

diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 12f39a2dffd4..91820f67275c 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -507,7 +507,8 @@  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;
@@ -519,14 +520,14 @@  static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt,
 		return ERR_PTR(-EINVAL);
 	}
 
-	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);