4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Guillaume Nault <g.nault@xxxxxxxxxxxx>
[ Upstream commit eb1c28c05894a4b1f6b56c5bf072205e64cfa280 ]
Check sockaddr_len before dereferencing sp->sa_protocol, to ensure that
it actually points to valid data.
Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Reported-by: syzbot+a70ac890b23b1bf29f5c@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Guillaume Nault <g.nault@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/l2tp/l2tp_ppp.c | 7 +++++++
1 file changed, 7 insertions(+)
--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -590,6 +590,13 @@ static int pppol2tp_connect(struct socke
lock_sock(sk);
error = -EINVAL;
+
+ if (sockaddr_len != sizeof(struct sockaddr_pppol2tp) &&
+ sockaddr_len != sizeof(struct sockaddr_pppol2tpv3) &&
+ sockaddr_len != sizeof(struct sockaddr_pppol2tpin6) &&
+ sockaddr_len != sizeof(struct sockaddr_pppol2tpv3in6))
+ goto end;
+
if (sp->sa_protocol != PX_PROTO_OL2TP)
goto end;