From 188ccb5583b8f501e1d0f5ba4f056afa141694e7 Mon Sep 17 00:00:00 2001 From: Patrick McHardy <kaber@trash.net> Date: Thu, 3 May 2007 03:27:01 -0700 Subject: [PATCH] [NETLINK]: Fix use after free in netlink_recvmsg When the user passes in MSG_TRUNC the skb is used after getting freed. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> --- net/netlink/af_netlink.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 7fc6b4da4f021..ac1ceadf4ed34 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -1246,16 +1246,14 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, siocb->scm = &scm; } siocb->scm->creds = *NETLINK_CREDS(skb); + if (flags & MSG_TRUNC) + copied = skb->len; skb_free_datagram(sk, skb); if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) netlink_dump(sk); scm_recv(sock, msg, siocb->scm, flags); - - if (flags & MSG_TRUNC) - copied = skb->len; - out: netlink_rcv_wake(sk); return err ? : copied; -- GitLab