diff options
| author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2017-10-07 11:07:47 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-11-18 11:22:24 +0100 |
| commit | 9d65d0ea55dcb813cea7df05602f233ad4843baf (patch) | |
| tree | 6ac0dd8341b1eac9641200e2aecb27cc6f641591 | |
| parent | 8cf061d919e2102d0de0379bafea6cce1405d786 (diff) | |
Input: ims-psu - check if CDC union descriptor is sane
commit ea04efee7635c9120d015dcdeeeb6988130cb67a upstream.
Before trying to use CDC union descriptor, try to validate whether that it
is sane by checking that intf->altsetting->extra is big enough and that
descriptor bLength is not too big and not too small.
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/input/misc/ims-pcu.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/input/misc/ims-pcu.c b/drivers/input/misc/ims-pcu.c index f4e8fbec6a94..b5304e264881 100644 --- a/drivers/input/misc/ims-pcu.c +++ b/drivers/input/misc/ims-pcu.c @@ -1635,13 +1635,25 @@ ims_pcu_get_cdc_union_desc(struct usb_interface *intf) return NULL; } - while (buflen > 0) { + while (buflen >= sizeof(*union_desc)) { union_desc = (struct usb_cdc_union_desc *)buf; + if (union_desc->bLength > buflen) { + dev_err(&intf->dev, "Too large descriptor\n"); + return NULL; + } + if (union_desc->bDescriptorType == USB_DT_CS_INTERFACE && union_desc->bDescriptorSubType == USB_CDC_UNION_TYPE) { dev_dbg(&intf->dev, "Found union header\n"); - return union_desc; + + if (union_desc->bLength >= sizeof(*union_desc)) + return union_desc; + + dev_err(&intf->dev, + "Union descriptor to short (%d vs %zd\n)", + union_desc->bLength, sizeof(*union_desc)); + return NULL; } buflen -= union_desc->bLength; |