[PATCH][next] net: sched: Use struct_size() helper in kvmalloc()

From: Gustavo A. R. Silva
Date: Wed Sep 29 2021 - 16:13:18 EST


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

Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
---
net/sched/sch_netem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 0c345e43a09a..ecbb10db1111 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -785,7 +785,7 @@ static int get_dist_table(struct Qdisc *sch, struct disttable **tbl,
if (!n || n > NETEM_DIST_MAX)
return -EINVAL;

- d = kvmalloc(sizeof(struct disttable) + n * sizeof(s16), GFP_KERNEL);
+ d = kvmalloc(struct_size(d, table, n), GFP_KERNEL);
if (!d)
return -ENOMEM;

--
2.27.0