4.9-stable review patch. If anyone has any objections, please let me know.
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From: Guillaume Nault g.nault@alphalink.fr
[ 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@syzkaller.appspotmail.com Signed-off-by: Guillaume Nault g.nault@alphalink.fr Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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;