| Message ID | 1532092853-14196-2-git-send-email-paolo.pisati@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | USB: fix out-of-bounds in usb_set_configuration | expand |
On 20.07.2018 15:20, Paolo Pisati wrote: > From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > Andrey Konovalov reported a possible out-of-bounds problem for a USB interface > association descriptor. He writes: > It seems there's no proper size check of a USB_DT_INTERFACE_ASSOCIATION > descriptor. It's only checked that the size is >= 2 in > usb_parse_configuration(), so find_iad() might do out-of-bounds access > to intf_assoc->bInterfaceCount. > > And he's right, we don't check for crazy descriptors of this type very well, so > resolve this problem. Yet another issue found by syzkaller... > > Reported-by: Andrey Konovalov <andreyknvl@google.com> > Tested-by: Andrey Konovalov <andreyknvl@google.com> > Cc: stable <stable@vger.kernel.org> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > (cherry picked from commit bd7a3fe770ebd8391d1c7d072ff88e9e76d063eb) > Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com> Acked-by: Stefan Bader <stefan.bader@canonical.com> > --- Needs CVE-2017-16531 added. > drivers/usb/core/config.c | 14 +++++++++++--- > include/uapi/linux/usb/ch9.h | 1 + > 2 files changed, 12 insertions(+), 3 deletions(-) > > diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c > index 9b05e88..755d82f 100644 > --- a/drivers/usb/core/config.c > +++ b/drivers/usb/core/config.c > @@ -513,15 +513,23 @@ static int usb_parse_configuration(struct usb_device *dev, int cfgidx, > > } else if (header->bDescriptorType == > USB_DT_INTERFACE_ASSOCIATION) { > + struct usb_interface_assoc_descriptor *d; > + > + d = (struct usb_interface_assoc_descriptor *)header; > + if (d->bLength < USB_DT_INTERFACE_ASSOCIATION_SIZE) { > + dev_warn(ddev, > + "config %d has an invalid interface association descriptor of length %d, skipping\n", > + cfgno, d->bLength); > + continue; > + } > + > if (iad_num == USB_MAXIADS) { > dev_warn(ddev, "found more Interface " > "Association Descriptors " > "than allocated for in " > "configuration %d\n", cfgno); > } else { > - config->intf_assoc[iad_num] = > - (struct usb_interface_assoc_descriptor > - *)header; > + config->intf_assoc[iad_num] = d; > iad_num++; > } > > diff --git a/include/uapi/linux/usb/ch9.h b/include/uapi/linux/usb/ch9.h > index aa33fd1..400196c 100644 > --- a/include/uapi/linux/usb/ch9.h > +++ b/include/uapi/linux/usb/ch9.h > @@ -705,6 +705,7 @@ struct usb_interface_assoc_descriptor { > __u8 iFunction; > } __attribute__ ((packed)); > > +#define USB_DT_INTERFACE_ASSOCIATION_SIZE 8 > > /*-------------------------------------------------------------------------*/ > >
Applied to trusty master-next. ...Juerg On 07/20/2018 03:20 PM, Paolo Pisati wrote: > From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > Andrey Konovalov reported a possible out-of-bounds problem for a USB interface > association descriptor. He writes: > It seems there's no proper size check of a USB_DT_INTERFACE_ASSOCIATION > descriptor. It's only checked that the size is >= 2 in > usb_parse_configuration(), so find_iad() might do out-of-bounds access > to intf_assoc->bInterfaceCount. > > And he's right, we don't check for crazy descriptors of this type very well, so > resolve this problem. Yet another issue found by syzkaller... > > Reported-by: Andrey Konovalov <andreyknvl@google.com> > Tested-by: Andrey Konovalov <andreyknvl@google.com> > Cc: stable <stable@vger.kernel.org> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > (cherry picked from commit bd7a3fe770ebd8391d1c7d072ff88e9e76d063eb) > Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com> > --- > drivers/usb/core/config.c | 14 +++++++++++--- > include/uapi/linux/usb/ch9.h | 1 + > 2 files changed, 12 insertions(+), 3 deletions(-) > > diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c > index 9b05e88..755d82f 100644 > --- a/drivers/usb/core/config.c > +++ b/drivers/usb/core/config.c > @@ -513,15 +513,23 @@ static int usb_parse_configuration(struct usb_device *dev, int cfgidx, > > } else if (header->bDescriptorType == > USB_DT_INTERFACE_ASSOCIATION) { > + struct usb_interface_assoc_descriptor *d; > + > + d = (struct usb_interface_assoc_descriptor *)header; > + if (d->bLength < USB_DT_INTERFACE_ASSOCIATION_SIZE) { > + dev_warn(ddev, > + "config %d has an invalid interface association descriptor of length %d, skipping\n", > + cfgno, d->bLength); > + continue; > + } > + > if (iad_num == USB_MAXIADS) { > dev_warn(ddev, "found more Interface " > "Association Descriptors " > "than allocated for in " > "configuration %d\n", cfgno); > } else { > - config->intf_assoc[iad_num] = > - (struct usb_interface_assoc_descriptor > - *)header; > + config->intf_assoc[iad_num] = d; > iad_num++; > } > > diff --git a/include/uapi/linux/usb/ch9.h b/include/uapi/linux/usb/ch9.h > index aa33fd1..400196c 100644 > --- a/include/uapi/linux/usb/ch9.h > +++ b/include/uapi/linux/usb/ch9.h > @@ -705,6 +705,7 @@ struct usb_interface_assoc_descriptor { > __u8 iFunction; > } __attribute__ ((packed)); > > +#define USB_DT_INTERFACE_ASSOCIATION_SIZE 8 > > /*-------------------------------------------------------------------------*/ > >
diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c index 9b05e88..755d82f 100644 --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -513,15 +513,23 @@ static int usb_parse_configuration(struct usb_device *dev, int cfgidx, } else if (header->bDescriptorType == USB_DT_INTERFACE_ASSOCIATION) { + struct usb_interface_assoc_descriptor *d; + + d = (struct usb_interface_assoc_descriptor *)header; + if (d->bLength < USB_DT_INTERFACE_ASSOCIATION_SIZE) { + dev_warn(ddev, + "config %d has an invalid interface association descriptor of length %d, skipping\n", + cfgno, d->bLength); + continue; + } + if (iad_num == USB_MAXIADS) { dev_warn(ddev, "found more Interface " "Association Descriptors " "than allocated for in " "configuration %d\n", cfgno); } else { - config->intf_assoc[iad_num] = - (struct usb_interface_assoc_descriptor - *)header; + config->intf_assoc[iad_num] = d; iad_num++; } diff --git a/include/uapi/linux/usb/ch9.h b/include/uapi/linux/usb/ch9.h index aa33fd1..400196c 100644 --- a/include/uapi/linux/usb/ch9.h +++ b/include/uapi/linux/usb/ch9.h @@ -705,6 +705,7 @@ struct usb_interface_assoc_descriptor { __u8 iFunction; } __attribute__ ((packed)); +#define USB_DT_INTERFACE_ASSOCIATION_SIZE 8 /*-------------------------------------------------------------------------*/