Merge tag 'linux-can-fixes-for-5.0-20190122' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can

Marc Kleine-Budde says:

====================
pull-request: can 2019-01-22

this is a pull request of 4 patches for net/master.

The first patch by is by Manfred Schlaegl and reverts a patch that caused wrong
warning messages in certain use cases. The next patch is by Oliver Hartkopp for
the bcm that adds sanity checks for the timer value before using it to detect
potential interger overflows. The last two patches are for the flexcan driver,
YueHaibing's patch fixes the the return value in the error path of the
flexcan_setup_stop_mode() function. The second patch is by Uwe Kleine-König and
fixes a NULL pointer deref on older flexcan cores in flexcan_chip_start().
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 42 insertions, 16 deletions

diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index 3b3f88ffab53..c05e4d50d43d 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -480,8 +480,6 @@ EXPORT_SYMBOL_GPL(can_put_echo_skb);
 struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr)
 {
 	struct can_priv *priv = netdev_priv(dev);
-	struct sk_buff *skb = priv->echo_skb[idx];
-	struct canfd_frame *cf;
 
 	if (idx >= priv->echo_skb_max) {
 		netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n",
@@ -489,20 +487,21 @@ struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8
 		return NULL;
 	}
 
-	if (!skb) {
-		netdev_err(dev, "%s: BUG! Trying to echo non existing skb: can_priv::echo_skb[%u]\n",
-			   __func__, idx);
-		return NULL;
-	}
+	if (priv->echo_skb[idx]) {
+		/* Using "struct canfd_frame::len" for the frame
+		 * length is supported on both CAN and CANFD frames.
+		 */
+		struct sk_buff *skb = priv->echo_skb[idx];
+		struct canfd_frame *cf = (struct canfd_frame *)skb->data;
+		u8 len = cf->len;
 
-	/* Using "struct canfd_frame::len" for the frame
-	 * length is supported on both CAN and CANFD frames.
-	 */
-	cf = (struct canfd_frame *)skb->data;
-	*len_ptr = cf->len;
-	priv->echo_skb[idx] = NULL;
+		*len_ptr = len;
+		priv->echo_skb[idx] = NULL;
 
-	return skb;
+		return skb;
+	}
+
+	return NULL;
 }
 
 /*
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 0f36eafe3ac1..1c66fb2ad76b 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -1106,7 +1106,7 @@ static int flexcan_chip_start(struct net_device *dev)
 		}
 	} else {
 		/* clear and invalidate unused mailboxes first */
-		for (i = FLEXCAN_TX_MB_RESERVED_OFF_FIFO; i <= priv->mb_count; i++) {
+		for (i = FLEXCAN_TX_MB_RESERVED_OFF_FIFO; i < priv->mb_count; i++) {
 			mb = flexcan_get_mb(priv, i);
 			priv->write(FLEXCAN_MB_CODE_RX_INACTIVE,
 				    &mb->can_ctrl);
@@ -1432,7 +1432,7 @@ static int flexcan_setup_stop_mode(struct platform_device *pdev)
 	gpr_np = of_find_node_by_phandle(phandle);
 	if (!gpr_np) {
 		dev_dbg(&pdev->dev, "could not find gpr node by phandle\n");
-		return PTR_ERR(gpr_np);
+		return -ENODEV;
 	}
 
 	priv = netdev_priv(dev);
diff --git a/net/can/bcm.c b/net/can/bcm.c
index 0af8f0db892a..79bb8afa9c0c 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -67,6 +67,9 @@
  */
 #define MAX_NFRAMES 256
 
+/* limit timers to 400 days for sending/timeouts */
+#define BCM_TIMER_SEC_MAX (400 * 24 * 60 * 60)
+
 /* use of last_frames[index].flags */
 #define RX_RECV    0x40 /* received data for this element */
 #define RX_THR     0x80 /* element not been sent due to throttle feature */
@@ -140,6 +143,22 @@ static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
 	return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
 }
 
+/* check limitations for timeval provided by user */
+static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head)
+{
+	if ((msg_head->ival1.tv_sec < 0) ||
+	    (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) ||
+	    (msg_head->ival1.tv_usec < 0) ||
+	    (msg_head->ival1.tv_usec >= USEC_PER_SEC) ||
+	    (msg_head->ival2.tv_sec < 0) ||
+	    (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) ||
+	    (msg_head->ival2.tv_usec < 0) ||
+	    (msg_head->ival2.tv_usec >= USEC_PER_SEC))
+		return true;
+
+	return false;
+}
+
 #define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
 #define OPSIZ sizeof(struct bcm_op)
 #define MHSIZ sizeof(struct bcm_msg_head)
@@ -873,6 +892,10 @@ static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
 	if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
 		return -EINVAL;
 
+	/* check timeval limitations */
+	if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
+		return -EINVAL;
+
 	/* check the given can_id */
 	op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
 	if (op) {
@@ -1053,6 +1076,10 @@ static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
 	     (!(msg_head->can_id & CAN_RTR_FLAG))))
 		return -EINVAL;
 
+	/* check timeval limitations */
+	if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
+		return -EINVAL;
+
 	/* check the given can_id */
 	op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
 	if (op) {