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