Thread (13 messages) flat view 13 messages, 4 authors, 2021-05-24

Re: [PATCH net v2] r8152: check the informaton of the device

From: Greg KH <gregkh@linuxfoundation.org>
Date: 2021-05-22 07:33:05
Also in: linux-usb, lkml

On Sat, May 22, 2021 at 01:24:54PM +0800, Hayes Wang wrote:
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().
It has been done in rtl_check_vendor_ok().

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 <redacted>
---
v2:
Use usb_find_common_endpoints() and usb_endpoint_num() to replace original
code.
Much better, just some tiny grammer changes below:
quoted hunk ↗ jump to hunk
remove the check of endpoint number in rtl8152_probe(). It has been done
in rtl_check_vendor_ok().

 drivers/net/usb/r8152.c | 44 ++++++++++++++++++++++++++++++++++++-----
 1 file changed, 39 insertions(+), 5 deletions(-)
diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 136ea06540ff..6e5230d6c721 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -8107,6 +8107,39 @@ 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 (alt->desc.bNumEndpoints < 3) {
+		dev_err(&intf->dev, "Unexpected bNumEndpoints %d\n", alt->desc.bNumEndpoints);
+		return false;
+	}
+
+	if (usb_find_common_endpoints(alt, &in, &out, &intr, NULL) < 0) {
+		dev_err(&intf->dev, "Miss Endpoints\n");
"Miss" feels ackward, how about "Invalid number of endpoints"?
+		return false;
+	}
+
+	if (usb_endpoint_num(in) != 1) {
+		dev_err(&intf->dev, "Invalid Rx Endpoint\n");
"Invalid number of Rx endpoints"
+		return false;
+	}
+
+	if (usb_endpoint_num(out) != 2) {
+		dev_err(&intf->dev, "Invalid Tx Endpoint\n");
"Invalid number of RX endpoints"
+		return false;
+	}
+
+	if (usb_endpoint_num(intr) != 3) {
+		dev_err(&intf->dev, "Invalid interrupt Endpoint\n");
"Invalid number of interrupt endpoints"

But really, this doesn't matter, all is good if you don't want to change
this :)

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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