| From: Guillaume Nault <g.nault@alphalink.fr> |
| Date: Fri, 3 Aug 2018 17:00:11 +0200 |
| Subject: l2tp: fix missing refcount drop in pppol2tp_tunnel_ioctl() |
| |
| commit f664e37dcc525768280cb94321424a09beb1c992 upstream. |
| |
| If 'session' is not NULL and is not a PPP pseudo-wire, then we fail to |
| drop the reference taken by l2tp_session_get(). |
| |
| Fixes: ecd012e45ab5 ("l2tp: filter out non-PPP sessions in pppol2tp_tunnel_ioctl()") |
| Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| [bwh: Backported to 3.16: Also call session->deref in both cases] |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| net/l2tp/l2tp_ppp.c | 13 +++++++++---- |
| 1 file changed, 9 insertions(+), 4 deletions(-) |
| |
| --- a/net/l2tp/l2tp_ppp.c |
| +++ b/net/l2tp/l2tp_ppp.c |
| @@ -1231,15 +1231,22 @@ static int pppol2tp_tunnel_ioctl(struct |
| l2tp_session_get(sock_net(sk), tunnel, |
| stats.session_id, true); |
| |
| - if (session && session->pwtype == L2TP_PWTYPE_PPP) { |
| - err = pppol2tp_session_ioctl(session, cmd, |
| - arg); |
| + if (!session) { |
| + err = -EBADR; |
| + break; |
| + } |
| + if (session->pwtype != L2TP_PWTYPE_PPP) { |
| if (session->deref) |
| session->deref(session); |
| l2tp_session_dec_refcount(session); |
| - } else { |
| err = -EBADR; |
| + break; |
| } |
| + |
| + err = pppol2tp_session_ioctl(session, cmd, arg); |
| + if (session->deref) |
| + session->deref(session); |
| + l2tp_session_dec_refcount(session); |
| break; |
| } |
| #ifdef CONFIG_XFRM |
