[PATCH 6.18 304/396] can: peak_usb: add bounds check for USB channel index

Greg Kroah-Hartman <[email protected]>
Newsgroups org.kernel.vger.stable,dev.linux.lists.patches
Message-ID <[email protected]>
6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: James Gao <[email protected]>

commit 39132f166ca8ce00ae60d8a9068e06a60943cc4b upstream.

The channel control index ctrl_idx is derived from rx->len which comes
directly from a device USB payload. The mask 0x0f allows values 0-15, but
the array size of usb_if->dev[] is only 2. Values 2-15 cause heap
out-of-bounds read, eventually causing kernel panic in the IRQ context.

Add bounds checking for ctrl_idx before the array access in both
pcan_usb_pro_handle_canmsg() and pcan_usb_pro_handle_error().

Fixes: d8a199355f8f ("can: usb: PEAK-System Technik PCAN-USB Pro specific part")
Signed-off-by: James Gao <[email protected]>
Reviewed-by: Vincent Mailhol <[email protected]>
Link: https://patch.msgid.link/TYWPR01MB8559DBAAAA6A7F410400329CF0012@TYWPR01MB8559.jpnprd01.prod.outlook.com
Cc: [email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 drivers/net/can/usb/peak_usb/pcan_usb_pro.c |   20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

--- a/drivers/net/can/usb/peak_usb/pcan_usb_pro.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_pro.c
@@ -534,12 +534,18 @@ static int pcan_usb_pro_handle_canmsg(st
 				      struct pcan_usb_pro_rxmsg *rx)
 {
 	const unsigned int ctrl_idx = (rx->len >> 4) & 0x0f;
-	struct peak_usb_device *dev = usb_if->dev[ctrl_idx];
-	struct net_device *netdev = dev->netdev;
+	struct peak_usb_device *dev;
+	struct net_device *netdev;
 	struct can_frame *can_frame;
 	struct sk_buff *skb;
 	struct skb_shared_hwtstamps *hwts;
 
+	if (ctrl_idx >= ARRAY_SIZE(usb_if->dev))
+		return -EINVAL;
+
+	dev = usb_if->dev[ctrl_idx];
+	netdev = dev->netdev;
+
 	skb = alloc_can_skb(netdev, &can_frame);
 	if (!skb)
 		return -ENOMEM;
@@ -573,14 +579,20 @@ static int pcan_usb_pro_handle_error(str
 {
 	const u16 raw_status = le16_to_cpu(er->status);
 	const unsigned int ctrl_idx = (er->channel >> 4) & 0x0f;
-	struct peak_usb_device *dev = usb_if->dev[ctrl_idx];
-	struct net_device *netdev = dev->netdev;
+	struct peak_usb_device *dev;
+	struct net_device *netdev;
 	struct can_frame *can_frame;
 	enum can_state new_state = CAN_STATE_ERROR_ACTIVE;
 	u8 err_mask = 0;
 	struct sk_buff *skb;
 	struct skb_shared_hwtstamps *hwts;
 
+	if (ctrl_idx >= ARRAY_SIZE(usb_if->dev))
+		return -EINVAL;
+
+	dev = usb_if->dev[ctrl_idx];
+	netdev = dev->netdev;
+
 	/* nothing should be sent while in BUS_OFF state */
 	if (dev->can.state == CAN_STATE_BUS_OFF)
 		return 0;
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.