From 143df6b3584a0f6314c71f5dd0e5de9bba5e453d Mon Sep 17 00:00:00 2001 From: Oleksij Rempel Date: Fri, 7 Aug 2020 12:51:58 +0200 Subject: [PATCH] can: j1939: socket: j1939_sk_bind(): make sure ml_priv is allocated commit af804b7826350d5af728dca4715e473338fbd7e5 upstream. This patch adds check to ensure that the struct net_device::ml_priv is allocated, as it is used later by the j1939 stack. The allocation is done by all mainline CAN network drivers, but when using bond or team devices this is not the case. Bail out if no ml_priv is allocated. Reported-by: syzbot+f03d384f3455d28833eb@syzkaller.appspotmail.com Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol") Cc: linux-stable # >= v5.4 Signed-off-by: Oleksij Rempel Link: https://lore.kernel.org/r/20200807105200.26441-4-o.rempel@pengutronix.de Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- net/can/j1939/socket.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c index f7587428febd..11d566c70a94 100644 --- a/net/can/j1939/socket.c +++ b/net/can/j1939/socket.c @@ -466,6 +466,14 @@ static int j1939_sk_bind(struct socket *sock, struct sockaddr *uaddr, int len) goto out_release_sock; } + if (!ndev->ml_priv) { + netdev_warn_once(ndev, + "No CAN mid layer private allocated, please fix your driver and use alloc_candev()!\n"); + dev_put(ndev); + ret = -ENODEV; + goto out_release_sock; + } + priv = j1939_netdev_start(ndev); dev_put(ndev); if (IS_ERR(priv)) {