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| author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2017-10-07 21:07:47 +0300 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2017-10-20 03:20:06 +0300 |
| commit | ea04efee7635c9120d015dcdeeeb6988130cb67a (patch) | |
| tree | 8f92d81e0afbc1d9106adf455e56365363ab6cf0 /drivers | |
| parent | 20ac95d52a28f55472a54cc751eeec49fd445cb1 (diff) | |
| download | linux-ea04efee7635c9120d015dcdeeeb6988130cb67a.tar.xz | |
Input: ims-psu - check if CDC union descriptor is sane
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>
Diffstat (limited to 'drivers')
| -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 6bf82ea8c918..ae473123583b 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; |