[PATCH][net-next] net: bridge: Use array_size() helper in copy_to_user()

From: Gustavo A. R. Silva
Date: Tue Sep 28 2021 - 16:08:41 EST


Use array_size() helper instead of the open-coded version in
copy_to_user(). These sorts of multiplication factors need
to be wrapped in array_size().

Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
---
net/bridge/br_ioctl.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/net/bridge/br_ioctl.c b/net/bridge/br_ioctl.c
index 793b0db9d9a3..49c268871fc1 100644
--- a/net/bridge/br_ioctl.c
+++ b/net/bridge/br_ioctl.c
@@ -71,7 +71,8 @@ static int get_fdb_entries(struct net_bridge *br, void __user *userbuf,

num = br_fdb_fillbuf(br, buf, maxnum, offset);
if (num > 0) {
- if (copy_to_user(userbuf, buf, num*sizeof(struct __fdb_entry)))
+ if (copy_to_user(userbuf, buf,
+ array_size(num, sizeof(struct __fdb_entry))))
num = -EFAULT;
}
kfree(buf);
@@ -188,7 +189,7 @@ int br_dev_siocdevprivate(struct net_device *dev, struct ifreq *rq, void __user
return -ENOMEM;

get_port_ifindices(br, indices, num);
- if (copy_to_user(argp, indices, num * sizeof(int)))
+ if (copy_to_user(argp, indices, array_size(num, sizeof(int))))
num = -EFAULT;
kfree(indices);
return num;
@@ -336,7 +337,8 @@ static int old_deviceless(struct net *net, void __user *uarg)

args[2] = get_bridge_ifindices(net, indices, args[2]);

- ret = copy_to_user(uarg, indices, args[2]*sizeof(int))
+ ret = copy_to_user(uarg, indices,
+ array_size(args[2], sizeof(int)))
? -EFAULT : args[2];

kfree(indices);
--
2.27.0