[PATCH 6.18 438/752] net: usb: pegasus: enable basic endpoint checking

Sasha Levin
2026-02-28T17:54:15Z

From: Ziyi Guo <n7l8m4@u.northwestern.edu>

[ Upstream commit 3d7e6ce34f4fcc7083510c28b17a7c36462a25d4 ]

pegasus_probe() fills URBs with hardcoded endpoint pipes without
verifying the endpoint descriptors:

- usb_rcvbulkpipe(dev, 1) for RX data
- usb_sndbulkpipe(dev, 2) for TX data
- usb_rcvintpipe(dev, 3) for status interrupts

A malformed USB device can present these endpoints with transfer types
that differ from what the driver assumes.

Add a pegasus_usb_ep enum for endpoint numbers, replacing magic
constants throughout. Add usb_check_bulk_endpoints() and
usb_check_int_endpoints() calls before any resource allocation to
verify endpoint types before use, rejecting devices with mismatched
descriptors at probe time, and avoid triggering assertion.

Similar fix to
- commit 90b7f2961798 ("net: usb: rtl8150: enable basic endpoint checking")
- commit 9e7021d2aeae ("net: usb: catc: enable basic endpoint checking")

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Ziyi Guo <n7l8m4@u.northwestern.edu>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260222050633.410165-1-n7l8m4@u.northwestern.edu
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/usb/pegasus.c | 35 ++++++++++++++++++++++++++++++-----
1 file changed, 30 insertions(+), 5 deletions(-)

diff --git a/drivers/net/usb/pegasus.c b/drivers/net/usb/pegasus.c
index c514483134f05..0f16a133c75d1 100644
--- a/drivers/net/usb/pegasus.c
+++ b/drivers/net/usb/pegasus.c
@@ -31,6 +31,17 @@ static const char driver_name[] = "pegasus";
BMSR_100FULL | BMSR_ANEGCAPABLE)
#define CARRIER_CHECK_DELAY (2 * HZ)

+/*
+ * USB endpoints.
+ */
+
+enum pegasus_usb_ep {
+ PEGASUS_USB_EP_CONTROL = 0,
+ PEGASUS_USB_EP_BULK_IN = 1,
+ PEGASUS_USB_EP_BULK_OUT = 2,
+ PEGASUS_USB_EP_INT_IN = 3,
+};
+
static bool loopback;
static bool mii_mode;
static char *devid;
@@ -545,7 +556,7 @@ static void read_bulk_callback(struct urb *urb)
goto tl_sched;
goon:
usb_fill_bulk_urb(pegasus->rx_urb, pegasus->usb,
- usb_rcvbulkpipe(pegasus->usb, 1),
+ usb_rcvbulkpipe(pegasus->usb, PEGASUS_USB_EP_BULK_IN),
pegasus->rx_skb->data, PEGASUS_MTU,
read_bulk_callback, pegasus);
rx_status = usb_submit_urb(pegasus->rx_urb, GFP_ATOMIC);
@@ -585,7 +596,7 @@ static void rx_fixup(struct tasklet_struct *t)
return;
}
usb_fill_bulk_urb(pegasus->rx_urb, pegasus->usb,
- usb_rcvbulkpipe(pegasus->usb, 1),
+ usb_rcvbulkpipe(pegasus->usb, PEGASUS_USB_EP_BULK_IN),
pegasus->rx_skb->data, PEGASUS_MTU,
read_bulk_callback, pegasus);
try_again:
@@ -713,7 +724,7 @@ static netdev_tx_t pegasus_start_xmit(struct sk_buff *skb,
((__le16 *) pegasus->tx_buff)[0] = cpu_to_le16(l16);
skb_copy_from_linear_data(skb, pegasus->tx_buff + 2, skb->len);
usb_fill_bulk_urb(pegasus->tx_urb, pegasus->usb,
- usb_sndbulkpipe(pegasus->usb, 2),
+ usb_sndbulkpipe(pegasus->usb, PEGASUS_USB_EP_BULK_OUT),
pegasus->tx_buff, count,
write_bulk_callback, pegasus);
if ((res = usb_submit_urb(pegasus->tx_urb, GFP_ATOMIC))) {
@@ -840,7 +851,7 @@ static int pegasus_open(struct net_device *net)
set_registers(pegasus, EthID, 6, net->dev_addr);

usb_fill_bulk_urb(pegasus->rx_urb, pegasus->usb,
- usb_rcvbulkpipe(pegasus->usb, 1),
+ usb_rcvbulkpipe(pegasus->usb, PEGASUS_USB_EP_BULK_IN),
pegasus->rx_skb->data, PEGASUS_MTU,
read_bulk_callback, pegasus);
if ((res = usb_submit_urb(pegasus->rx_urb, GFP_KERNEL))) {
@@ -851,7 +862,7 @@ static int pegasus_open(struct net_device *net)
}

usb_fill_int_urb(pegasus->intr_urb, pegasus->usb,
- usb_rcvintpipe(pegasus->usb, 3),
+ usb_rcvintpipe(pegasus->usb, PEGASUS_USB_EP_INT_IN),
pegasus->intr_buff, sizeof(pegasus->intr_buff),
intr_callback, pegasus, pegasus->intr_interval);
if ((res = usb_submit_urb(pegasus->intr_urb, GFP_KERNEL))) {
@@ -1136,10 +1147,24 @@ static int pegasus_probe(struct usb_interface *intf,
pegasus_t *pegasus;
int dev_index = id - pegasus_ids;
int res = -ENOMEM;
+ static const u8 bulk_ep_addr[] = {
+ PEGASUS_USB_EP_BULK_IN | USB_DIR_IN,
+ PEGASUS_USB_EP_BULK_OUT | USB_DIR_OUT,
+ 0};
+ static const u8 int_ep_addr[] = {
+ PEGASUS_USB_EP_INT_IN | USB_DIR_IN,
+ 0};

if (pegasus_blacklisted(dev))
return -ENODEV;

+ /* Verify that all required endpoints are present */
+ if (!usb_check_bulk_endpoints(intf, bulk_ep_addr) ||
+ !usb_check_int_endpoints(intf, int_ep_addr)) {
+ dev_err(&intf->dev, "Missing or invalid endpoints\n");
+ return -ENODEV;
+ }
+
net = alloc_etherdev(sizeof(struct pegasus));
if (!net)
goto out;
--
2.51.0