Messages in this thread | | | Date | Tue, 27 Jul 2021 15:28:20 +0200 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH AUTOSEL 5.13 06/21] USB: core: Fix incorrect pipe calculation in do_proc_control() |
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On Tue, Jul 27, 2021 at 09:18:53AM -0400, Sasha Levin wrote: > From: Alan Stern <stern@rowland.harvard.edu> > > [ Upstream commit b0863f1927323110e3d0d69f6adb6a91018a9a3c ] > > When the user submits a control URB via usbfs, the user supplies the > bRequestType value and the kernel uses it to compute the pipe value. > However, do_proc_control() performs this computation incorrectly in > the case where the bRequestType direction bit is set to USB_DIR_IN and > the URB's transfer length is 0: The pipe's direction is also set to IN > but it should be OUT, which is the direction the actual transfer will > use regardless of bRequestType. > > Commit 5cc59c418fde ("USB: core: WARN if pipe direction != setup > packet direction") added a check to compare the direction bit in the > pipe value to a control URB's actual direction and to WARN if they are > different. This can be triggered by the incorrect computation > mentioned above, as found by syzbot. > > This patch fixes the computation, thus avoiding the WARNing. > > Reported-and-tested-by: syzbot+72af3105289dcb4c055b@syzkaller.appspotmail.com > Signed-off-by: Alan Stern <stern@rowland.harvard.edu> > Link: https://lore.kernel.org/r/20210712185436.GB326369@rowland.harvard.edu > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Signed-off-by: Sasha Levin <sashal@kernel.org> > --- > drivers/usb/core/devio.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c > index 2218941d35a3..73b60f013b20 100644 > --- a/drivers/usb/core/devio.c > +++ b/drivers/usb/core/devio.c > @@ -1133,7 +1133,7 @@ static int do_proc_control(struct usb_dev_state *ps, > "wIndex=%04x wLength=%04x\n", > ctrl->bRequestType, ctrl->bRequest, ctrl->wValue, > ctrl->wIndex, ctrl->wLength); > - if (ctrl->bRequestType & 0x80) { > + if ((ctrl->bRequestType & USB_DIR_IN) && ctrl->wLength) { > pipe = usb_rcvctrlpipe(dev, 0); > snoop_urb(dev, NULL, pipe, ctrl->wLength, tmo, SUBMIT, NULL, 0); > > -- > 2.30.2 >
This is not needed in any kernel that does not also have 5cc59c418fde ("USB: core: WARN if pipe direction != setup packet direction"), which showed up in 5.14-rc1, so please drop this from all of the AUTOSEL trees.
thanks,
greg k-h
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