From 0fb6bd06e06792469acc15bbe427361b56ada528 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 11 Sep 2013 21:56:54 +0200 Subject: HID: LG: validate HID output report details A HID device could send a malicious output report that would cause the lg, lg3, and lg4 HID drivers to write beyond the output report allocation during an event, causing a heap overflow: [ 325.245240] usb 1-1: New USB device found, idVendor=046d, idProduct=c287 ... [ 414.518960] BUG kmalloc-4096 (Not tainted): Redzone overwritten Additionally, while lg2 did correctly validate the report details, it was cleaned up and shortened. CVE-2013-2893 Signed-off-by: Kees Cook Cc: stable@vger.kernel.org Reviewed-by: Benjamin Tissoires Signed-off-by: Jiri Kosina --- drivers/hid/hid-lg3ff.c | 29 ++++++----------------------- 1 file changed, 6 insertions(+), 23 deletions(-) (limited to 'drivers/hid/hid-lg3ff.c') diff --git a/drivers/hid/hid-lg3ff.c b/drivers/hid/hid-lg3ff.c index e52f181..8c2da18 100644 --- a/drivers/hid/hid-lg3ff.c +++ b/drivers/hid/hid-lg3ff.c @@ -66,10 +66,11 @@ static int hid_lg3ff_play(struct input_dev *dev, void *data, int x, y; /* - * Maxusage should always be 63 (maximum fields) - * likely a better way to ensure this data is clean + * Available values in the field should always be 63, but we only use up to + * 35. Instead, clear the entire area, however big it is. */ - memset(report->field[0]->value, 0, sizeof(__s32)*report->field[0]->maxusage); + memset(report->field[0]->value, 0, + sizeof(__s32) * report->field[0]->report_count); switch (effect->type) { case FF_CONSTANT: @@ -129,32 +130,14 @@ static const signed short ff3_joystick_ac[] = { int lg3ff_init(struct hid_device *hid) { struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list); - struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list; struct input_dev *dev = hidinput->input; - struct hid_report *report; - struct hid_field *field; const signed short *ff_bits = ff3_joystick_ac; int error; int i; - /* Find the report to use */ - if (list_empty(report_list)) { - hid_err(hid, "No output report found\n"); - return -1; - } - /* Check that the report looks ok */ - report = list_entry(report_list->next, struct hid_report, list); - if (!report) { - hid_err(hid, "NULL output report\n"); - return -1; - } - - field = report->field[0]; - if (!field) { - hid_err(hid, "NULL field\n"); - return -1; - } + if (!hid_validate_values(hid, HID_OUTPUT_REPORT, 0, 0, 35)) + return -ENODEV; /* Assume single fixed device G940 */ for (i = 0; ff_bits[i] >= 0; i++) -- cgit v1.1