| From 128c16a682034263eb519c89bc0934eeb6fa8cfa Mon Sep 17 00:00:00 2001 |
| From: Javier Martinez Canillas <javierm@redhat.com> |
| Date: Fri, 11 Dec 2020 19:19:21 +0100 |
| Subject: [PATCH] usb: Avoid possible out-of-bound accesses caused by malicious |
| devices |
| |
| The maximum number of configurations and interfaces are fixed but there is |
| no out-of-bound checking to prevent a malicious USB device to report large |
| values for these and cause accesses outside the arrays' memory. |
| |
| Fixes: CVE-2020-25647 |
| |
| Reported-by: Joseph Tartaro <joseph.tartaro@ioactive.com> |
| Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com> |
| Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> |
| Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> |
| Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com> |
| --- |
| grub-core/bus/usb/usb.c | 15 ++++++++++++--- |
| include/grub/usb.h | 10 +++++++--- |
| 2 files changed, 19 insertions(+), 6 deletions(-) |
| |
| diff --git a/grub-core/bus/usb/usb.c b/grub-core/bus/usb/usb.c |
| index 8da5e4c..7cb3cc2 100644 |
| --- a/grub-core/bus/usb/usb.c |
| +++ b/grub-core/bus/usb/usb.c |
| @@ -75,6 +75,9 @@ grub_usb_controller_iterate (grub_usb_controller_iterate_hook_t hook, |
| grub_usb_err_t |
| grub_usb_clear_halt (grub_usb_device_t dev, int endpoint) |
| { |
| + if (endpoint >= GRUB_USB_MAX_TOGGLE) |
| + return GRUB_USB_ERR_BADDEVICE; |
| + |
| dev->toggle[endpoint] = 0; |
| return grub_usb_control_msg (dev, (GRUB_USB_REQTYPE_OUT |
| | GRUB_USB_REQTYPE_STANDARD |
| @@ -134,10 +137,10 @@ grub_usb_device_initialize (grub_usb_device_t dev) |
| return err; |
| descdev = &dev->descdev; |
| |
| - for (i = 0; i < 8; i++) |
| + for (i = 0; i < GRUB_USB_MAX_CONF; i++) |
| dev->config[i].descconf = NULL; |
| |
| - if (descdev->configcnt == 0) |
| + if (descdev->configcnt == 0 || descdev->configcnt > GRUB_USB_MAX_CONF) |
| { |
| err = GRUB_USB_ERR_BADDEVICE; |
| goto fail; |
| @@ -172,6 +175,12 @@ grub_usb_device_initialize (grub_usb_device_t dev) |
| /* Skip the configuration descriptor. */ |
| pos = dev->config[i].descconf->length; |
| |
| + if (dev->config[i].descconf->numif > GRUB_USB_MAX_IF) |
| + { |
| + err = GRUB_USB_ERR_BADDEVICE; |
| + goto fail; |
| + } |
| + |
| /* Read all interfaces. */ |
| for (currif = 0; currif < dev->config[i].descconf->numif; currif++) |
| { |
| @@ -217,7 +226,7 @@ grub_usb_device_initialize (grub_usb_device_t dev) |
| |
| fail: |
| |
| - for (i = 0; i < 8; i++) |
| + for (i = 0; i < GRUB_USB_MAX_CONF; i++) |
| grub_free (dev->config[i].descconf); |
| |
| return err; |
| diff --git a/include/grub/usb.h b/include/grub/usb.h |
| index 512ae1d..6475c55 100644 |
| --- a/include/grub/usb.h |
| +++ b/include/grub/usb.h |
| @@ -23,6 +23,10 @@ |
| #include <grub/usbdesc.h> |
| #include <grub/usbtrans.h> |
| |
| +#define GRUB_USB_MAX_CONF 8 |
| +#define GRUB_USB_MAX_IF 32 |
| +#define GRUB_USB_MAX_TOGGLE 256 |
| + |
| typedef struct grub_usb_device *grub_usb_device_t; |
| typedef struct grub_usb_controller *grub_usb_controller_t; |
| typedef struct grub_usb_controller_dev *grub_usb_controller_dev_t; |
| @@ -167,7 +171,7 @@ struct grub_usb_configuration |
| struct grub_usb_desc_config *descconf; |
| |
| /* Interfaces associated to this configuration. */ |
| - struct grub_usb_interface interf[32]; |
| + struct grub_usb_interface interf[GRUB_USB_MAX_IF]; |
| }; |
| |
| struct grub_usb_hub_port |
| @@ -191,7 +195,7 @@ struct grub_usb_device |
| struct grub_usb_controller controller; |
| |
| /* Device configurations (after opening the device). */ |
| - struct grub_usb_configuration config[8]; |
| + struct grub_usb_configuration config[GRUB_USB_MAX_CONF]; |
| |
| /* Device address. */ |
| int addr; |
| @@ -203,7 +207,7 @@ struct grub_usb_device |
| int initialized; |
| |
| /* Data toggle values (used for bulk transfers only). */ |
| - int toggle[256]; |
| + int toggle[GRUB_USB_MAX_TOGGLE]; |
| |
| /* Used by libusb wrapper. Schedulded for removal. */ |
| void *data; |
| -- |
| 2.14.2 |
| |