Re: WARNING in usb_submit_urb (3)

From: Alan Stern
Date: Mon Oct 15 2018 - 13:12:52 EST


On Mon, 15 Oct 2018, Andrey Konovalov wrote:

> On Mon, Oct 15, 2018 at 5:22 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
> > On Fri, 12 Oct 2018, syzbot wrote:
> >
> >> Hello,
> >>
> >> syzbot found the following crash on:
> >>
> >> HEAD commit: 9dcd936c5312 Merge tag 'for-4.19/dm-fixes-4' of git://git...
> >> git tree: upstream
> >> console output: https://syzkaller.appspot.com/x/log.txt?x=123b8da1400000
> >> kernel config: https://syzkaller.appspot.com/x/.config?x=88e9a8a39dc0be2d
> >> dashboard link: https://syzkaller.appspot.com/bug?extid=24a30223a4b609bb802e
> >> compiler: gcc (GCC) 8.0.1 20180413 (experimental)
> >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13888991400000
> >> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1476e5e6400000
> >>
> >> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> >> Reported-by: syzbot+24a30223a4b609bb802e@xxxxxxxxxxxxxxxxxxxxxxxxx
> >>
> >> IPVS: ftp: loaded support on port[0] = 21
> >> ------------[ cut here ]------------
> >> usb usb7: BOGUS urb flags, 1 --> 0
> >> WARNING: CPU: 0 PID: 5828 at drivers/usb/core/urb.c:503
> >> usb_submit_urb+0x717/0x14e0 drivers/usb/core/urb.c:502
> >> Kernel panic - not syncing: panic_on_warn set ...
> >
> > This should have been fixed by commit 7a68d9fb8510 ("USB: usbdevfs:
> > sanitize flags more"). Was that commit not present in the kernel you
> > tested?
>
> The commit is there, AFAICT. This must be a different issue.

Ah, I see the problem. In fact it is the same issue, but the commit
mentioned above contains an error (is_in gets tested too soon). The
fix is below; can you check it?

Alan Stern



Index: usb-4.x/drivers/usb/core/devio.c
===================================================================
--- usb-4.x.orig/drivers/usb/core/devio.c
+++ usb-4.x/drivers/usb/core/devio.c
@@ -1474,8 +1474,6 @@ static int proc_do_submiturb(struct usb_
u = 0;
switch (uurb->type) {
case USBDEVFS_URB_TYPE_CONTROL:
- if (is_in)
- allow_short = true;
if (!usb_endpoint_xfer_control(&ep->desc))
return -EINVAL;
/* min 8 byte setup packet */
@@ -1505,6 +1503,8 @@ static int proc_do_submiturb(struct usb_
is_in = 0;
uurb->endpoint &= ~USB_DIR_IN;
}
+ if (is_in)
+ allow_short = true;
snoop(&ps->dev->dev, "control urb: bRequestType=%02x "
"bRequest=%02x wValue=%04x "
"wIndex=%04x wLength=%04x\n",