113 lines
3.6 KiB
Diff
113 lines
3.6 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Javier Martinez Canillas <javierm@redhat.com>
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Date: Fri, 11 Dec 2020 19:19:21 +0100
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Subject: [PATCH] usb: Avoid possible out-of-bound accesses caused by malicious
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devices
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The maximum number of configurations and interfaces are fixed but there is
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no out-of-bound checking to prevent a malicious USB device to report large
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values for these and cause accesses outside the arrays' memory.
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Fixes: CVE-2020-25647
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Reported-by: Joseph Tartaro (IOActive)
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Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
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Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
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Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
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---
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grub-core/bus/usb/usb.c | 15 ++++++++++++---
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include/grub/usb.h | 10 +++++++---
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2 files changed, 19 insertions(+), 6 deletions(-)
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diff --git a/grub-core/bus/usb/usb.c b/grub-core/bus/usb/usb.c
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index 8da5e4c74..7cb3cc230 100644
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--- a/grub-core/bus/usb/usb.c
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+++ b/grub-core/bus/usb/usb.c
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@@ -75,6 +75,9 @@ grub_usb_controller_iterate (grub_usb_controller_iterate_hook_t hook,
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grub_usb_err_t
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grub_usb_clear_halt (grub_usb_device_t dev, int endpoint)
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{
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+ if (endpoint >= GRUB_USB_MAX_TOGGLE)
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+ return GRUB_USB_ERR_BADDEVICE;
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+
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dev->toggle[endpoint] = 0;
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return grub_usb_control_msg (dev, (GRUB_USB_REQTYPE_OUT
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| GRUB_USB_REQTYPE_STANDARD
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@@ -134,10 +137,10 @@ grub_usb_device_initialize (grub_usb_device_t dev)
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return err;
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descdev = &dev->descdev;
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- for (i = 0; i < 8; i++)
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+ for (i = 0; i < GRUB_USB_MAX_CONF; i++)
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dev->config[i].descconf = NULL;
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- if (descdev->configcnt == 0)
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+ if (descdev->configcnt == 0 || descdev->configcnt > GRUB_USB_MAX_CONF)
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{
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err = GRUB_USB_ERR_BADDEVICE;
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goto fail;
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@@ -172,6 +175,12 @@ grub_usb_device_initialize (grub_usb_device_t dev)
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/* Skip the configuration descriptor. */
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pos = dev->config[i].descconf->length;
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+ if (dev->config[i].descconf->numif > GRUB_USB_MAX_IF)
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+ {
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+ err = GRUB_USB_ERR_BADDEVICE;
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+ goto fail;
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+ }
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+
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/* Read all interfaces. */
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for (currif = 0; currif < dev->config[i].descconf->numif; currif++)
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{
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@@ -217,7 +226,7 @@ grub_usb_device_initialize (grub_usb_device_t dev)
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fail:
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- for (i = 0; i < 8; i++)
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+ for (i = 0; i < GRUB_USB_MAX_CONF; i++)
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grub_free (dev->config[i].descconf);
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return err;
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diff --git a/include/grub/usb.h b/include/grub/usb.h
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index 512ae1dd0..6475c552f 100644
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--- a/include/grub/usb.h
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+++ b/include/grub/usb.h
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@@ -23,6 +23,10 @@
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#include <grub/usbdesc.h>
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#include <grub/usbtrans.h>
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+#define GRUB_USB_MAX_CONF 8
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+#define GRUB_USB_MAX_IF 32
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+#define GRUB_USB_MAX_TOGGLE 256
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+
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typedef struct grub_usb_device *grub_usb_device_t;
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typedef struct grub_usb_controller *grub_usb_controller_t;
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typedef struct grub_usb_controller_dev *grub_usb_controller_dev_t;
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@@ -167,7 +171,7 @@ struct grub_usb_configuration
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struct grub_usb_desc_config *descconf;
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/* Interfaces associated to this configuration. */
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- struct grub_usb_interface interf[32];
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+ struct grub_usb_interface interf[GRUB_USB_MAX_IF];
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};
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struct grub_usb_hub_port
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@@ -191,7 +195,7 @@ struct grub_usb_device
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struct grub_usb_controller controller;
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/* Device configurations (after opening the device). */
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- struct grub_usb_configuration config[8];
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+ struct grub_usb_configuration config[GRUB_USB_MAX_CONF];
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/* Device address. */
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int addr;
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@@ -203,7 +207,7 @@ struct grub_usb_device
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int initialized;
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/* Data toggle values (used for bulk transfers only). */
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- int toggle[256];
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+ int toggle[GRUB_USB_MAX_TOGGLE];
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/* Used by libusb wrapper. Schedulded for removal. */
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void *data;
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