From: Alan Stern <stern@rowland.harvard.edu>
To: syzbot <syzbot+9b57a46bf1801ce2a2ca@syzkaller.appspotmail.com>
Cc: benjamin.tissoires@redhat.com, jikos@kernel.org,
linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-usb@vger.kernel.org, mkubecek@suse.cz,
syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] WARNING in hid_submit_ctrl/usb_submit_urb
Date: Thu, 19 Aug 2021 15:53:00 -0400 [thread overview]
Message-ID: <20210819195300.GA8613@rowland.harvard.edu> (raw)
In-Reply-To: <00000000000009e24705c9ecf9b3@google.com>
On Thu, Aug 19, 2021 at 10:35:11AM -0700, syzbot wrote:
> Hello,
>
> syzbot has tested the proposed patch but the reproducer is still triggering an issue:
> WARNING in hid_submit_ctrl/usb_submit_urb
>
> cm6533_jd 0003:0D8C:0022.0001: submit_ctrl: maxpacket 64 len 0 padlen 0
> ------------[ cut here ]------------
> usb 1-1: BOGUS control dir, pipe 80000280 doesn't match bRequestType a1
Ah. The padding code doesn't add anything if the length is
already a multiple of the maxpacket value, and of course 0 is such
a multiple.
The following simplified variant of Michal's patch should fix the
problem.
Alan Stern
#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 794c7931a242
Index: usb-devel/drivers/hid/usbhid/hid-core.c
===================================================================
--- usb-devel.orig/drivers/hid/usbhid/hid-core.c
+++ usb-devel/drivers/hid/usbhid/hid-core.c
@@ -377,27 +377,23 @@ static int hid_submit_ctrl(struct hid_de
len = hid_report_len(report);
if (dir == USB_DIR_OUT) {
usbhid->urbctrl->pipe = usb_sndctrlpipe(hid_to_usb_dev(hid), 0);
- usbhid->urbctrl->transfer_buffer_length = len;
if (raw_report) {
memcpy(usbhid->ctrlbuf, raw_report, len);
kfree(raw_report);
usbhid->ctrl[usbhid->ctrltail].raw_report = NULL;
}
} else {
- int maxpacket, padlen;
+ int maxpacket;
usbhid->urbctrl->pipe = usb_rcvctrlpipe(hid_to_usb_dev(hid), 0);
maxpacket = usb_maxpacket(hid_to_usb_dev(hid),
usbhid->urbctrl->pipe, 0);
- if (maxpacket > 0) {
- padlen = DIV_ROUND_UP(len, maxpacket);
- padlen *= maxpacket;
- if (padlen > usbhid->bufsize)
- padlen = usbhid->bufsize;
- } else
- padlen = 0;
- usbhid->urbctrl->transfer_buffer_length = padlen;
+ len += (len == 0); /* Don't allow 0-length reports */
+ len = round_up(len, maxpacket);
+ if (len > usbhid->bufsize)
+ len = usbhid->bufsize;
}
+ usbhid->urbctrl->transfer_buffer_length = len;
usbhid->urbctrl->dev = hid_to_usb_dev(hid);
usbhid->cr->bRequestType = USB_TYPE_CLASS | USB_RECIP_INTERFACE | dir;
next prev parent reply other threads:[~2021-08-19 19:53 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-18 15:46 [syzbot] WARNING in hid_submit_ctrl/usb_submit_urb syzbot
2021-08-18 9:14 ` syzbot
2021-08-18 18:49 ` Alan Stern
2021-08-18 20:13 ` syzbot
2021-08-19 15:26 ` Alan Stern
2021-08-19 17:35 ` syzbot
2021-08-19 19:53 ` Alan Stern [this message]
2021-08-20 0:40 ` syzbot
2021-08-20 14:06 ` Alan Stern
2021-08-24 11:53 ` Jiri Kosina
2021-08-24 12:34 ` Benjamin Tissoires
2021-08-31 9:51 ` Benjamin Tissoires
2021-08-31 13:34 ` Alan Stern
2021-08-31 19:53 ` Jiri Kosina
2021-09-01 15:38 ` Alan Stern
2021-09-01 15:51 ` Michal Kubecek
2021-08-24 11:50 ` Michal Kubecek
2021-08-30 19:22 ` Oleksandr Natalenko
2021-08-18 19:01 ` Alan Stern
2021-08-18 19:39 ` syzbot
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