On 15.11.21 08:28, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 048ff8629e11 Merge tag 'usb-5.16-rc1' of git://git.kernel...
> git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
> console output: https://syzkaller.appspot.com/x/log.txt?x=1480ade1b00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=d6b387bc5d3e50f3
> dashboard link: https://syzkaller.appspot.com/bug?extid=63ee658b9a100ffadbe2
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1313cb7cb00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16a2f676b00000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+63ee658b9a100ffadbe2@xxxxxxxxxxxxxxxxxxxxxxxxx
>
#syz test https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git 048ff8629e11
>From 2f7c84e39b74ae581bf7d01dbc69d820d09da20a Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum@xxxxxxxx>
Date: Thu, 18 Nov 2021 18:15:03 +0100
Subject: [PATCH] usbnet: sanity check for endpoint types
A malicious device can pretend to be a device with a known
configuration of endpoints yet present endpoints of the wrong type.
Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx>
---
drivers/net/usb/usbnet.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 9a6450f796dc..aaa897e6ba29 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1772,6 +1772,11 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
} else if (!info->in || !info->out)
status = usbnet_get_endpoints (dev, udev);
else {
+ /*sanity checks */
+ if (!usb_endpoint_is_bulk_in(&udev->cur_altsetting->endpoint[info->in].desc))
+ goto out3;
+ if (!usb_endpoint_is_bulk_out(&udev->cur_altsetting->endpoint[info->out].desc))
+ goto out3;
dev->in = usb_rcvbulkpipe (xdev, info->in);
dev->out = usb_sndbulkpipe (xdev, info->out);
if (!(info->flags & FLAG_NO_SETINT))
--
2.26.2
