From c142cba37de29f740a3852f01f59876af8ae462a Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Tue, 6 Dec 2022 21:12:59 +0100 Subject: [PATCH] can: af_can: fix NULL pointer dereference in can_rcv_filter commit 0acc442309a0a1b01bcdaa135e56e6398a49439c upstream. Analogue to commit 8aa59e355949 ("can: af_can: fix NULL pointer dereference in can_rx_register()") we need to check for a missing initialization of ml_priv in the receive path of CAN frames. Since commit 4e096a18867a ("net: introduce CAN specific pointer in the struct net_device") the check for dev->type to be ARPHRD_CAN is not sufficient anymore since bonding or tun netdevices claim to be CAN devices but do not initialize ml_priv accordingly. Fixes: 4e096a18867a ("net: introduce CAN specific pointer in the struct net_device") Reported-by: syzbot+2d7f58292cb5b29eb5ad@syzkaller.appspotmail.com Reported-by: Wei Chen Signed-off-by: Oliver Hartkopp Link: https://lore.kernel.org/all/20221206201259.3028-1-socketcan@hartkopp.net Cc: stable@vger.kernel.org Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- net/can/af_can.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/can/af_can.c b/net/can/af_can.c index 4ddefa6a3e05..20d2dcb7c97a 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -680,7 +680,7 @@ static int can_rcv(struct sk_buff *skb, struct net_device *dev, { struct canfd_frame *cfd = (struct canfd_frame *)skb->data; - if (unlikely(dev->type != ARPHRD_CAN || skb->len != CAN_MTU)) { + if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) || skb->len != CAN_MTU)) { pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d\n", dev->type, skb->len); goto free_skb; @@ -706,7 +706,7 @@ static int canfd_rcv(struct sk_buff *skb, struct net_device *dev, { struct canfd_frame *cfd = (struct canfd_frame *)skb->data; - if (unlikely(dev->type != ARPHRD_CAN || skb->len != CANFD_MTU)) { + if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) || skb->len != CANFD_MTU)) { pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d\n", dev->type, skb->len); goto free_skb;