diff options
| author | Greg Kroah-Hartman | 2017-09-19 15:07:17 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2017-09-19 17:27:16 +0200 |
| commit | bd7a3fe770ebd8391d1c7d072ff88e9e76d063eb (patch) | |
| tree | 7c3907fa163d0cf35761735ae3c6d8e59a9ee8cd | |
| parent | bcd6a7aa13800afc1418e6b29d944d882214939a (diff) | |
USB: fix out-of-bounds in usb_set_configuration
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>
| -rw-r--r-- | drivers/usb/core/config.c | 14 | ||||
| -rw-r--r-- | 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 854c8d66cfbe..68b54bd88d1e 100644 --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -643,15 +643,23 @@ 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 ce1169af39d7..2a5d63040a0b 100644 --- a/include/uapi/linux/usb/ch9.h +++ b/include/uapi/linux/usb/ch9.h @@ -780,6 +780,7 @@ struct usb_interface_assoc_descriptor { __u8 iFunction; } __attribute__ ((packed)); +#define USB_DT_INTERFACE_ASSOCIATION_SIZE 8 /*-------------------------------------------------------------------------*/ |