[patch 10/31] HID: Do not discard truncated input reports

[Greg KH]

-stable review patch.  If anyone has any objections, please let us know.

------------------
From: Adam Kropelin <akropel1@xxxxxxxxxxxxxxxx>

HID: Do not discard truncated input reports

Truncated reports should not be discarded since it prevents buggy
devices from communicating with userspace.

Prior to the regession introduced in 2.6.20, a shorter-than-expected
report in hid_input_report() was passed thru after having the missing
bytes cleared. This behavior was established over a few patches in the
2.6.early-teens days, including commit
cd6104572bca9e4afe0dcdb8ecd65ef90b01297b.

This patch restores the previous behavior and fixes the regression.

Signed-off-by: Adam Kropelin <akropel1@xxxxxxxxxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 drivers/hid/hid-core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -975,7 +975,7 @@ int hid_input_report(struct hid_device *
 
 	if (size < rsize) {
 		dbg("report %d is too short, (%d < %d)", report->id, size, rsize);
-		return -1;
+		memset(data + size, 0, rsize - size);
 	}
 
 	if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)

-- 
-
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