Doing so, we save one call to get data we already have in the struct.
Also, since there is no guarantee that getname use sockaddr_ll
parameter beyond its size, we add a little bit of security here.
It should do not do beyond MAX_ADDR_LEN, but syzbot found that
ax25_getname writes more (72 bytes, the size of full_sockaddr_ax25,
versus 20 + 32 bytes of sockaddr_ll + MAX_ADDR_LEN in syzbot repro).
Fixes: 3a4d5c94e9593 ("vhost_net: a kernel-level virtio server")
Reported-by: syzbot+f2a62d07a5198c819c7b@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Eugenio Pérez <eperezma@xxxxxxxxxx>
---
drivers/vhost/net.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index e158159671fa..18e205eeb9af 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -1414,10 +1414,6 @@ static int vhost_net_release(struct inode *inode, struct file *f)
static struct socket *get_raw_socket(int fd)
{
- struct {
- struct sockaddr_ll sa;
- char buf[MAX_ADDR_LEN];
- } uaddr;
int r;
struct socket *sock = sockfd_lookup(fd, &r);
@@ -1430,11 +1426,7 @@ static struct socket *get_raw_socket(int fd)
goto err;
}
- r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa, 0);
- if (r < 0)
- goto err;
-
- if (uaddr.sa.sll_family != AF_PACKET) {
+ if (sock->sk->sk_family != AF_PACKET) {
r = -EPFNOSUPPORT;
goto err;
}
--
2.18.1
