diff mbox series

[net,v3] r8152: check the informaton of the device

Message ID 1394712342-15778-365-Taiwan-albertk@realtek.com
State New
Headers show
Series [net,v3] r8152: check the informaton of the device | expand

Commit Message

Hayes Wang May 24, 2021, 6:49 a.m. UTC
Verify some fields of the USB descriptor to make sure the driver
could be used by the device.

Besides, remove the check of endpoint number in rtl8152_probe().
usb_find_common_endpoints() includes it.

BugLink: https://syzkaller.appspot.com/bug?id=912c9c373656996801b4de61f1e3cb326fe940aa
Reported-by: syzbot+95afd23673f5dd295c57@syzkaller.appspotmail.com
Fixes: c2198943e33b ("r8152: search the configuration of vendor mode")
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
---
v3:
Remove the check of endpoint number in rtl_check_vendor_ok().

Adjust the error message and ccommit message.

v2:
Use usb_find_common_endpoints() and usb_endpoint_num() to replace original
code.

remove the check of endpoint number in rtl8152_probe(). It has been done
in rtl_check_vendor_ok().

 drivers/net/usb/r8152.c | 42 ++++++++++++++++++++++++++++++++++++-----
 1 file changed, 37 insertions(+), 5 deletions(-)

Comments

Johan Hovold May 24, 2021, 9:13 a.m. UTC | #1
On Mon, May 24, 2021 at 08:54:50AM +0000, Hayes Wang wrote:
> Johan Hovold <johan@kernel.org>
> > Sent: Monday, May 24, 2021 4:01 PM
> [...]
> > >  	/* The vendor mode is not always config #1, so to find it out. */
> > >  	udev = interface_to_usbdev(intf);
> > >  	c = udev->config;
> > >  	num_configs = udev->descriptor.bNumConfigurations;
> > > +	if (num_configs < 2)
> > > +		return false;
> > > +
> > 
> > Nit: This check looks unnecessary also as the driver can handle a single
> > configuration just fine, and by removing it you'd be logging "Unexpected
> > Device\n" below also in the single config case.
> 
> I just want to distinguish the devices.
> It is acceptable if the device contains only one configuration.
> A mistake occurs if the device has more configurations and
> there is no expected one.
> I would remove it if you think it is better.

I'm fine with keeping the check too (e.g. as an optimisation of sort),
it's just a bit inconsistent to not log an error in that one error path.

Johan
diff mbox series

Patch

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 136ea06540ff..f6abb2fbf972 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -8107,6 +8107,37 @@  static void r8156b_init(struct r8152 *tp)
 	tp->coalesce = 15000;	/* 15 us */
 }
 
+static bool rtl_check_vendor_ok(struct usb_interface *intf)
+{
+	struct usb_host_interface *alt = intf->cur_altsetting;
+	struct usb_endpoint_descriptor *in, *out, *intr;
+
+	if (usb_find_common_endpoints(alt, &in, &out, &intr, NULL) < 0) {
+		dev_err(&intf->dev, "Expected endpoints are not found\n");
+		return false;
+	}
+
+	/* Check Rx endpoint address */
+	if (usb_endpoint_num(in) != 1) {
+		dev_err(&intf->dev, "Invalid Rx endpoint address\n");
+		return false;
+	}
+
+	/* Check Tx endpoint address */
+	if (usb_endpoint_num(out) != 2) {
+		dev_err(&intf->dev, "Invalid Tx endpoint address\n");
+		return false;
+	}
+
+	/* Check interrupt endpoint address */
+	if (usb_endpoint_num(intr) != 3) {
+		dev_err(&intf->dev, "Invalid interrupt endpoint address\n");
+		return false;
+	}
+
+	return true;
+}
+
 static bool rtl_vendor_mode(struct usb_interface *intf)
 {
 	struct usb_host_interface *alt = intf->cur_altsetting;
@@ -8115,12 +8146,15 @@  static bool rtl_vendor_mode(struct usb_interface *intf)
 	int i, num_configs;
 
 	if (alt->desc.bInterfaceClass == USB_CLASS_VENDOR_SPEC)
-		return true;
+		return rtl_check_vendor_ok(intf);
 
 	/* The vendor mode is not always config #1, so to find it out. */
 	udev = interface_to_usbdev(intf);
 	c = udev->config;
 	num_configs = udev->descriptor.bNumConfigurations;
+	if (num_configs < 2)
+		return false;
+
 	for (i = 0; i < num_configs; (i++, c++)) {
 		struct usb_interface_descriptor	*desc = NULL;
 
@@ -8135,7 +8169,8 @@  static bool rtl_vendor_mode(struct usb_interface *intf)
 		}
 	}
 
-	WARN_ON_ONCE(i == num_configs);
+	if (i == num_configs)
+		dev_err(&intf->dev, "Unexpected Device\n");
 
 	return false;
 }
@@ -9381,9 +9416,6 @@  static int rtl8152_probe(struct usb_interface *intf,
 	if (!rtl_vendor_mode(intf))
 		return -ENODEV;
 
-	if (intf->cur_altsetting->desc.bNumEndpoints < 3)
-		return -ENODEV;
-
 	usb_reset_device(udev);
 	netdev = alloc_etherdev(sizeof(struct r8152));
 	if (!netdev) {