3.5.7.23 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> commit cc6b54aa54bf40b762cab45a9fc8aa81653146eb upstream. 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 Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> Acked-by: Kees Cook <keescook@xxxxxxxxxxxx> Signed-off-by: Jiri Kosina <jkosina@xxxxxxx> [ luis: backported to 3.5: - dropped changes to hid_report_raw_event() as these depend on commit b94e3c9 "HID: hid-core: optimize in case of hidraw" ] Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx> --- drivers/hid/hid-core.c | 10 ++++++---- drivers/hid/hid-input.c | 11 ++++++++++- 2 files changed, 16 insertions(+), 5 deletions(-) diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 4043d73..adca1b0 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -226,9 +226,9 @@ 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 +255,8 @@ 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 +267,14 @@ 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; diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index c460b74..0c218f8 100644 --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c @@ -470,6 +470,10 @@ 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) { @@ -1134,7 +1138,11 @@ 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]); @@ -1143,6 +1151,7 @@ static void report_features(struct hid_device *hid) drv->feature_mapping(hid, rep->field[i], rep->field[i]->usage + j); } + } } /* -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html