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

Commit Message

Gustavo A. R. Silva Sept. 29, 2021, 8:17 p.m. UTC

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 <[e-mail]>
---
 net/sched/sch_netem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch

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;