diff options
| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-09-19 16:07:17 +0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-11-11 16:33:39 +0300 |
| commit | cc81fff9d62e32a27b1f16dab1a6172935792ab7 (patch) | |
| tree | 07da2be1577bf7857e2d77064d143e34aa7a1f99 /drivers/usb | |
| parent | c0003557dbdec4ec1976ea7be9534abef758297b (diff) | |
| download | linux-cc81fff9d62e32a27b1f16dab1a6172935792ab7.tar.xz | |
USB: fix out-of-bounds in usb_set_configuration
commit bd7a3fe770ebd8391d1c7d072ff88e9e76d063eb upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/core/config.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c index 627038883c55..a6686236fcec 100644 --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -607,15 +607,23 @@ 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++; } |