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Diffstat (limited to 'net/llc/af_llc.c')
-rw-r--r--net/llc/af_llc.c24
1 files changed, 16 insertions, 8 deletions
diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c
index 9b06c380866b..20551cfb7da6 100644
--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -928,14 +928,15 @@ copy_uaddr:
*/
static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
{
+ DECLARE_SOCKADDR(struct sockaddr_llc *, addr, msg->msg_name);
struct sock *sk = sock->sk;
struct llc_sock *llc = llc_sk(sk);
- DECLARE_SOCKADDR(struct sockaddr_llc *, addr, msg->msg_name);
int flags = msg->msg_flags;
int noblock = flags & MSG_DONTWAIT;
+ int rc = -EINVAL, copied = 0, hdrlen, hh_len;
struct sk_buff *skb = NULL;
+ struct net_device *dev;
size_t size = 0;
- int rc = -EINVAL, copied = 0, hdrlen;
dprintk("%s: sending from %02X to %02X\n", __func__,
llc->laddr.lsap, llc->daddr.lsap);
@@ -955,22 +956,29 @@ static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
if (rc)
goto out;
}
- hdrlen = llc->dev->hard_header_len + llc_ui_header_len(sk, addr);
+ dev = llc->dev;
+ hh_len = LL_RESERVED_SPACE(dev);
+ hdrlen = llc_ui_header_len(sk, addr);
size = hdrlen + len;
- if (size > llc->dev->mtu)
- size = llc->dev->mtu;
+ size = min_t(size_t, size, READ_ONCE(dev->mtu));
copied = size - hdrlen;
rc = -EINVAL;
if (copied < 0)
goto out;
release_sock(sk);
- skb = sock_alloc_send_skb(sk, size, noblock, &rc);
+ skb = sock_alloc_send_skb(sk, hh_len + size, noblock, &rc);
lock_sock(sk);
if (!skb)
goto out;
- skb->dev = llc->dev;
+ if (sock_flag(sk, SOCK_ZAPPED) ||
+ llc->dev != dev ||
+ hdrlen != llc_ui_header_len(sk, addr) ||
+ hh_len != LL_RESERVED_SPACE(dev) ||
+ size > READ_ONCE(dev->mtu))
+ goto out;
+ skb->dev = dev;
skb->protocol = llc_proto_type(addr->sllc_arphrd);
- skb_reserve(skb, hdrlen);
+ skb_reserve(skb, hh_len + hdrlen);
rc = memcpy_from_msg(skb_put(skb, copied), msg, copied);
if (rc)
goto out;