diff options
Diffstat (limited to 'drivers/hid/hid-magicmouse.c')
| -rw-r--r-- | drivers/hid/hid-magicmouse.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/drivers/hid/hid-magicmouse.c b/drivers/hid/hid-magicmouse.c index ccdb29559fec..0480e7d216bc 100644 --- a/drivers/hid/hid-magicmouse.c +++ b/drivers/hid/hid-magicmouse.c @@ -383,8 +383,8 @@ static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tda } } -static int magicmouse_raw_event(struct hid_device *hdev, - struct hid_report *report, u8 *data, int size) +static int __magicmouse_raw_event(struct hid_device *hdev, + struct hid_report *report, u8 *data, int size, bool nested) { struct magicmouse_sc *msc = hid_get_drvdata(hdev); struct input_dev *input = msc->input; @@ -495,6 +495,15 @@ static int magicmouse_raw_event(struct hid_device *hdev, * packet. */ + /* + * A double report only ever wraps two normal reports, so it is + * never nested. Refuse to recurse a second time; otherwise a + * malicious device could chain DOUBLE_REPORT_ID packets to drive + * unbounded recursion and overflow the kernel stack. + */ + if (nested) + return 0; + /* Ensure that we have at least 2 elements (report type and size) */ if (size < 2) return 0; @@ -506,9 +515,9 @@ static int magicmouse_raw_event(struct hid_device *hdev, return 0; } - magicmouse_raw_event(hdev, report, data + 2, data[1]); - magicmouse_raw_event(hdev, report, data + 2 + data[1], - size - 2 - data[1]); + __magicmouse_raw_event(hdev, report, data + 2, data[1], true); + __magicmouse_raw_event(hdev, report, data + 2 + data[1], + size - 2 - data[1], true); return 0; default: return 0; @@ -534,6 +543,12 @@ static int magicmouse_raw_event(struct hid_device *hdev, return 1; } +static int magicmouse_raw_event(struct hid_device *hdev, + struct hid_report *report, u8 *data, int size) +{ + return __magicmouse_raw_event(hdev, report, data, size, false); +} + static int magicmouse_event(struct hid_device *hdev, struct hid_field *field, struct hid_usage *usage, __s32 value) { |