This is a note to let you know that I've just added the patch titled
USB: usbdevfs: sanitize flags more
to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 7a68d9fb851012829c29e770621905529bd9490b Mon Sep 17 00:00:00 2001
From: Oliver Neukum oneukum@suse.com Date: Wed, 5 Sep 2018 12:07:02 +0200 Subject: USB: usbdevfs: sanitize flags more
Requesting a ZERO_PACKET or not is sensible only for output. In the input direction the device decides. Likewise accepting short packets makes sense only for input.
This allows operation with panic_on_warn without opening up a local DOS.
Signed-off-by: Oliver Neukum oneukum@suse.com Reported-by: syzbot+843efa30c8821bd69f53@syzkaller.appspotmail.com Fixes: 0cb54a3e47cb ("USB: debugging code shouldn't alter control flow") Cc: stable stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/core/devio.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index 6ce77b33da61..263dd2f309fb 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -1434,10 +1434,13 @@ static int proc_do_submiturb(struct usb_dev_state *ps, struct usbdevfs_urb *uurb struct async *as = NULL; struct usb_ctrlrequest *dr = NULL; unsigned int u, totlen, isofrmlen; - int i, ret, is_in, num_sgs = 0, ifnum = -1; + int i, ret, num_sgs = 0, ifnum = -1; int number_of_packets = 0; unsigned int stream_id = 0; void *buf; + bool is_in; + bool allow_short = false; + bool allow_zero = false; unsigned long mask = USBDEVFS_URB_SHORT_NOT_OK | USBDEVFS_URB_BULK_CONTINUATION | USBDEVFS_URB_NO_FSBR | @@ -1471,6 +1474,8 @@ static int proc_do_submiturb(struct usb_dev_state *ps, struct usbdevfs_urb *uurb 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 */ @@ -1511,6 +1516,10 @@ static int proc_do_submiturb(struct usb_dev_state *ps, struct usbdevfs_urb *uurb break;
case USBDEVFS_URB_TYPE_BULK: + if (!is_in) + allow_zero = true; + else + allow_short = true; switch (usb_endpoint_type(&ep->desc)) { case USB_ENDPOINT_XFER_CONTROL: case USB_ENDPOINT_XFER_ISOC: @@ -1531,6 +1540,10 @@ static int proc_do_submiturb(struct usb_dev_state *ps, struct usbdevfs_urb *uurb if (!usb_endpoint_xfer_int(&ep->desc)) return -EINVAL; interrupt_urb: + if (!is_in) + allow_zero = true; + else + allow_short = true; break;
case USBDEVFS_URB_TYPE_ISO: @@ -1676,9 +1689,9 @@ static int proc_do_submiturb(struct usb_dev_state *ps, struct usbdevfs_urb *uurb u = (is_in ? URB_DIR_IN : URB_DIR_OUT); if (uurb->flags & USBDEVFS_URB_ISO_ASAP) u |= URB_ISO_ASAP; - if (uurb->flags & USBDEVFS_URB_SHORT_NOT_OK && is_in) + if (allow_short && uurb->flags & USBDEVFS_URB_SHORT_NOT_OK) u |= URB_SHORT_NOT_OK; - if (uurb->flags & USBDEVFS_URB_ZERO_PACKET) + if (allow_zero && uurb->flags & USBDEVFS_URB_ZERO_PACKET) u |= URB_ZERO_PACKET; if (uurb->flags & USBDEVFS_URB_NO_INTERRUPT) u |= URB_NO_INTERRUPT;