[PATCH] openvswitch: Change the return type for vport_ops.send function hook to int

From: Nathan Huckleberry
Date: Tue Sep 13 2022 - 19:07:53 EST


All usages of the vport_ops struct have the .send field set to
dev_queue_xmit or internal_dev_recv. Since most usages are set to
dev_queue_xmit, the function hook should match the signature of
dev_queue_xmit.

The only call to vport_ops->send() is in net/openvswitch/vport.c and it
throws away the return value.

This mismatched return type breaks forward edge kCFI since the underlying
function definition does not match the function hook definition.

Reported-by: Dan Carpenter <error27@xxxxxxxxx>
Link: https://github.com/ClangBuiltLinux/linux/issues/1703
Cc: llvm@xxxxxxxxxxxxxxx
Signed-off-by: Nathan Huckleberry <nhuck@xxxxxxxxxx>
---
net/openvswitch/vport-internal_dev.c | 2 +-
net/openvswitch/vport.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/openvswitch/vport-internal_dev.c b/net/openvswitch/vport-internal_dev.c
index 35f42c9821c2..74c88a6baa43 100644
--- a/net/openvswitch/vport-internal_dev.c
+++ b/net/openvswitch/vport-internal_dev.c
@@ -190,7 +190,7 @@ static void internal_dev_destroy(struct vport *vport)
rtnl_unlock();
}

-static netdev_tx_t internal_dev_recv(struct sk_buff *skb)
+static int internal_dev_recv(struct sk_buff *skb)
{
struct net_device *netdev = skb->dev;

diff --git a/net/openvswitch/vport.h b/net/openvswitch/vport.h
index 7d276f60c000..6ff45e8a0868 100644
--- a/net/openvswitch/vport.h
+++ b/net/openvswitch/vport.h
@@ -132,7 +132,7 @@ struct vport_ops {
int (*set_options)(struct vport *, struct nlattr *);
int (*get_options)(const struct vport *, struct sk_buff *);

- netdev_tx_t (*send) (struct sk_buff *skb);
+ int (*send)(struct sk_buff *skb);
struct module *owner;
struct list_head list;
};
--
2.37.2.789.g6183377224-goog