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| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-09-19 15:07:17 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-10-12 09:18:02 +0200 |
| commit | 0502bf54bd01e8dbf4a057fe76f974074b5fb7e6 (patch) | |
| tree | 24e41f57c63fe36e031e2e9817c5af96fdcbbbca | |
| parent | 8c7124a5295a10043daf2154bc01a437ece9d0f9 (diff) | |
| download | linux-stable-0502bf54bd01e8dbf4a057fe76f974074b5fb7e6.tar.gz | |
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>
| -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 69dfaea4dede..49e66fb1ce87 100644 --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -538,15 +538,23 @@ 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 aa33fd1b2d4f..400196c45b3c 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 /*-------------------------------------------------------------------------*/ |