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HID: validate feature and input report details

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When dealing with usage_index, be sure to properly use unsigned instead of
int to avoid overflows.

When working on report fields, always validate that their report_counts are
in bounds.
Without this, a HID device could report a malicious feature report that
could trick the driver into a heap overflow:

[  634.885003] usb 1-1: New USB device found, idVendor=0596, idProduct=0500
...
[  676.469629] BUG kmalloc-192 (Tainted: G        W   ): Redzone overwritten

CVE-2013-2897

Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Benjamin Tissoires 2013-09-11 21:56:57 +02:00 committed by Jiri Kosina
parent 0a9cd0a80a
commit cc6b54aa54
2 changed files with 17 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
drivers/hid/hid-core.c
View File

@ -94,7 +94,6 @@ EXPORT_SYMBOL_GPL(hid_register_report);
static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages, unsigned values)
{
struct hid_field *field;
int i;
if (report->maxfield == HID_MAX_FIELDS) {
hid_err(report->device, "too many fields in report\n");
@ -113,9 +112,6 @@ static struct hid_field *hid_register_field(struct hid_report *report, unsigned
field->value = (s32 *)(field->usage + usages);
field->report = report;
for (i = 0; i < usages; i++)
field->usage[i].usage_index = i;
return field;
}
@ -226,9 +222,9 @@ static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsign
{
struct hid_report *report;
struct hid_field *field;
int usages;
unsigned usages;
unsigned offset;
int i;
unsigned i;
report = hid_register_report(parser->device, report_type, parser->global.report_id);
if (!report) {
@ -255,7 +251,8 @@ static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsign
if (!parser->local.usage_index) /* Ignore padding fields */
return 0;
usages = max_t(int, parser->local.usage_index, parser->global.report_count);
usages = max_t(unsigned, parser->local.usage_index,
parser->global.report_count);
field = hid_register_field(report, usages, parser->global.report_count);
if (!field)
@ -266,13 +263,14 @@ static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsign
field->application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);
for (i = 0; i < usages; i++) {
int j = i;
unsigned j = i;
/* Duplicate the last usage we parsed if we have excess values */
if (i >= parser->local.usage_index)
j = parser->local.usage_index - 1;
field->usage[i].hid = parser->local.usage[j];
field->usage[i].collection_index =
parser->local.collection_index[j];
field->usage[i].usage_index = i;
}
field->maxusage = usages;
@ -1354,7 +1352,7 @@ int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, int size,
goto out;
}
if (hid->claimed != HID_CLAIMED_HIDRAW) {
if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
for (a = 0; a < report->maxfield; a++)
hid_input_field(hid, report->field[a], cdata, interrupt);
hdrv = hid->driver;

11
drivers/hid/hid-input.c
View File

@ -485,6 +485,10 @@ static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel
if (field->flags & HID_MAIN_ITEM_CONSTANT)
goto ignore;
/* Ignore if report count is out of bounds. */
if (field->report_count < 1)
goto ignore;
/* only LED usages are supported in output fields */
if (field->report_type == HID_OUTPUT_REPORT &&
(usage->hid & HID_USAGE_PAGE) != HID_UP_LED) {
@ -1236,7 +1240,11 @@ static void report_features(struct hid_device *hid)
rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
list_for_each_entry(rep, &rep_enum->report_list, list)
for (i = 0; i < rep->maxfield; i++)
for (i = 0; i < rep->maxfield; i++) {
/* Ignore if report count is out of bounds. */
if (rep->field[i]->report_count < 1)
continue;
for (j = 0; j < rep->field[i]->maxusage; j++) {
/* Verify if Battery Strength feature is available */
hidinput_setup_battery(hid, HID_FEATURE_REPORT, rep->field[i]);
@ -1245,6 +1253,7 @@ static void report_features(struct hid_device *hid)
drv->feature_mapping(hid, rep->field[i],
rep->field[i]->usage + j);
}
}
}
static struct hid_input *hidinput_allocate(struct hid_device *hid)