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authorGuillaume Nault <g.nault@alphalink.fr>2017-03-31 13:02:26 +0200
committerDavid S. Miller <davem@davemloft.net>2017-04-01 20:16:41 -0700
commit57377d63547861919ee634b845c7caa38de4a452 (patch)
tree5e00b7be9f0d3abc3b0901662867aba202835c0a /net
parent61b9a047729bb230978178bca6729689d0c50ca2 (diff)
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l2tp: ensure session can't get removed during pppol2tp_session_ioctl()
Holding a reference on session is required before calling pppol2tp_session_ioctl(). The session could get freed while processing the ioctl otherwise. Since pppol2tp_session_ioctl() uses the session's socket, we also need to take a reference on it in l2tp_session_get(). Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/l2tp/l2tp_ppp.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c
index 123b6a2411a0..827e55c41ba2 100644
--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -1141,11 +1141,18 @@ static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
if (stats.session_id != 0) {
/* resend to session ioctl handler */
struct l2tp_session *session =
- l2tp_session_find(sock_net(sk), tunnel, stats.session_id);
- if (session != NULL)
- err = pppol2tp_session_ioctl(session, cmd, arg);
- else
+ l2tp_session_get(sock_net(sk), tunnel,
+ stats.session_id, true);
+
+ if (session) {
+ err = pppol2tp_session_ioctl(session, cmd,
+ arg);
+ if (session->deref)
+ session->deref(session);
+ l2tp_session_dec_refcount(session);
+ } else {
err = -EBADR;
+ }
break;
}
#ifdef CONFIG_XFRM