From cc6b54aa54bf40b762cab45a9fc8aa81653146eb Mon Sep 17 00:00:00 2001 From: Benjamin Tissoires Date: Wed, 11 Sep 2013 21:56:57 +0200 Subject: HID: validate feature and input report details 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 Acked-by: Kees Cook Signed-off-by: Jiri Kosina --- drivers/hid/hid-input.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'drivers/hid/hid-input.c') diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index b420f4a0fd28..8741d953dcc8 100644 --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c @@ -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) -- cgit v1.2.1