* [PATCH v2][net-next] net_sched: Use struct_size() and flex_array_size() helpers
@ 2021-09-28 19:31 Gustavo A. R. Silva
0 siblings, 0 replies; only message in thread
From: Gustavo A. R. Silva @ 2021-09-28 19:31 UTC (permalink / raw)
To: Jamal Hadi Salim, Cong Wang, Jiri Pirko, David S. Miller, Jakub Kicinski
Cc: netdev, linux-kernel, Gustavo A. R. Silva, linux-hardening
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>
---
Changes in v2:
- Rebase on top of net-next/master.
net/sched/sch_api.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 5e90e9b160e3..e1a40d3b1ed0 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -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);
--
2.27.0
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