In newer kernels this issue has been fixed at a central location with

commit 2e1c42391ff2556387b3cb6308b24f6f65619feb Author: Greg Kroah-Hartman gregkh@linuxfoundation.org Date: Thu Sep 21 16:58:48 2017 +0200

USB: core: harden cdc_parse_cdc_header

on anything older the parsing had not been centralised, so a separate fix for each driver is necessary.

Signed-off-by: Oliver Neukum oneukum@suse.com --- drivers/net/usb/cdc_ether.c | 9 ++++++++- drivers/usb/class/cdc-acm.c | 8 +++++++- drivers/usb/class/cdc-wdm.c | 2 ++ 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c index 3651f3cd474e..0f2fde0820dd 100644 --- a/drivers/net/usb/cdc_ether.c +++ b/drivers/net/usb/cdc_ether.c @@ -144,6 +144,8 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf) dev_dbg(&intf->dev, "extra CDC header\n"); goto bad_desc; } + if (len < sizeof(struct usb_cdc_header_desc)) + break; info->header = (void *) buf; if (info->header->bLength != sizeof(*info->header)) { dev_dbg(&intf->dev, "CDC header len %u\n", @@ -157,6 +159,8 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf) */ if (rndis) { struct usb_cdc_acm_descriptor *acm; + if (len < sizeof(struct usb_cdc_acm_descriptor)) + break;

acm = (void *) buf; if (acm->bmCapabilities) { @@ -173,6 +177,8 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf) dev_dbg(&intf->dev, "extra CDC union\n"); goto bad_desc; } + if (len < sizeof(struct usb_cdc_union_desc)) + break; info->u = (void *) buf; if (info->u->bLength != sizeof(*info->u)) { dev_dbg(&intf->dev, "CDC union len %u\n", @@ -231,6 +237,8 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf) dev_dbg(&intf->dev, "extra CDC ether\n"); goto bad_desc; } + if (len < sizeof(struct usb_cdc_ether_desc)) + break; info->ether = (void *) buf; if (info->ether->bLength != sizeof(*info->ether)) { dev_dbg(&intf->dev, "CDC ether len %u\n", @@ -248,7 +256,6 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf) dev_dbg(&intf->dev, "extra MDLM descriptor\n"); goto bad_desc; } - desc = (void *)buf;

if (desc->bLength != sizeof(*desc)) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index ea93b35b1c6d..8957ee57f62d 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -1019,7 +1019,7 @@ static int acm_probe(struct usb_interface *intf, } }

- while (buflen > 0) { + while (buflen >= 3) { /* minimum length making sense */ if (buffer[1] != USB_DT_CS_INTERFACE) { dev_err(&intf->dev, "skipping garbage\n"); goto next_desc; @@ -1027,6 +1027,8 @@ static int acm_probe(struct usb_interface *intf,

switch (buffer[2]) { case USB_CDC_UNION_TYPE: /* we've found it */ + if (buflen < sizeof(struct usb_cdc_union_desc)) + break; if (union_header) { dev_err(&intf->dev, "More than one " "union descriptor, skipping ...\n"); @@ -1035,6 +1037,8 @@ static int acm_probe(struct usb_interface *intf, union_header = (struct usb_cdc_union_desc *)buffer; break; case USB_CDC_COUNTRY_TYPE: /* export through sysfs*/ + if (buflen < sizeof(struct usb_cdc_country_functional_desc)) + break; cfd = (struct usb_cdc_country_functional_desc *)buffer; break; case USB_CDC_HEADER_TYPE: /* maybe check version */ @@ -1043,6 +1047,8 @@ static int acm_probe(struct usb_interface *intf, ac_management_function = buffer[3]; break; case USB_CDC_CALL_MANAGEMENT_TYPE: + if (buflen < 4) + break; call_management_function = buffer[3]; call_interface_num = buffer[4]; if ((quirks & NOT_A_MODEM) == 0 && (call_management_function & 3) != 3) diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index 07133d0c971b..f61b5e138bc7 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -851,6 +851,8 @@ static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id) case USB_CDC_HEADER_TYPE: break; case USB_CDC_DMM_TYPE: + if (buflen < sizeof(struct usb_cdc_dmm_desc)) + break; dmhd = (struct usb_cdc_dmm_desc *)buffer; maxcom = le16_to_cpu(dmhd->wMaxCommand); dev_dbg(&intf->dev,