Just checked that the stable patch for 8aa59e355949 ("can: af_can: fix NULL pointer dereference in can_rx_register()") has been applied down to linux-5.4.y
Same works with this patch.
Just the current 6.1-rc has some changes in this section which makes this backport stable patch necessary.
Best, Oliver
On 09.12.22 19:07, Oliver Hartkopp wrote:
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.
Upstream commit 0acc442309a0 ("can: af_can: fix NULL pointer dereference in can_rcv_filter")
Fixes: 4e096a18867a ("net: introduce CAN specific pointer in the struct net_device") Reported-by: syzbot+2d7f58292cb5b29eb5ad@syzkaller.appspotmail.com Reported-by: Wei Chen harperchen1110@gmail.com Signed-off-by: Oliver Hartkopp socketcan@hartkopp.net Cc: stable@vger.kernel.org # 5.12 .. 6.0
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 1fb49d51b25d..4392f1d9c027 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -678,11 +678,11 @@ static void can_receive(struct sk_buff *skb, struct net_device *dev) static int can_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_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; }
@@ -704,11 +704,11 @@ static int can_rcv(struct sk_buff *skb, struct net_device *dev, static int canfd_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_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; }