From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20120103223035.796372807@clark.kroah.org> Date: Tue, 03 Jan 2012 14:30:11 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Alexandru Juncu , Kunjan Naik , "David S. Miller" Subject: [53/67] llc: llc_cmsg_rcv was getting called after sk_eat_skb. In-Reply-To: <20120103223043.GA26738@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alex Juncu [ Upstream commit 9cef310fcdee12b49b8b4c96fd8f611c8873d284 ] Received non stream protocol packets were calling llc_cmsg_rcv that used a skb after that skb was released by sk_eat_skb. This caused received STP packets to generate kernel panics. Signed-off-by: Alexandru Juncu Signed-off-by: Kunjan Naik Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/llc/af_llc.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) --- a/net/llc/af_llc.c +++ b/net/llc/af_llc.c @@ -833,15 +833,15 @@ static int llc_ui_recvmsg(struct kiocb * copied += used; len -= used; + /* For non stream protcols we get one packet per recvmsg call */ + if (sk->sk_type != SOCK_STREAM) + goto copy_uaddr; + if (!(flags & MSG_PEEK)) { sk_eat_skb(sk, skb, 0); *seq = 0; } - /* For non stream protcols we get one packet per recvmsg call */ - if (sk->sk_type != SOCK_STREAM) - goto copy_uaddr; - /* Partial read */ if (used + offset < skb->len) continue; @@ -857,6 +857,12 @@ copy_uaddr: } if (llc_sk(sk)->cmsg_flags) llc_cmsg_rcv(msg, skb); + + if (!(flags & MSG_PEEK)) { + sk_eat_skb(sk, skb, 0); + *seq = 0; + } + goto out; }