| From 3afcbf7a2b2698ce7dc70e0a9eb5c1551a128e0f Mon Sep 17 00:00:00 2001 |
| From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= <eperezma@redhat.com> |
| Date: Fri, 21 Feb 2020 12:06:56 +0100 |
| Subject: [PATCH] vhost: Check docket sk_family instead of call getname |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| commit 42d84c8490f9f0931786f1623191fcab397c3d64 upstream. |
| |
| 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@syzkaller.appspotmail.com |
| Signed-off-by: Eugenio Pérez <eperezma@redhat.com> |
| Acked-by: Michael S. Tsirkin <mst@redhat.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c |
| index 247e5585af5d..873a692478c4 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; |
| } |
| -- |
| 2.7.4 |
| |