[PATCH 3.16 003/125] HID: logitech: fix bounds checking on LED report size

From: Greg Kroah-Hartman
Date: Wed Sep 03 2014 - 18:17:11 EST


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

------------------

From: Jiri Kosina <jkosina@xxxxxxx>

commit 51217e69697fba92a06e07e16f55c9a52d8e8945 upstream.

The check on report size for REPORT_TYPE_LEDS in logi_dj_ll_raw_request()
is wrong; the current check doesn't make any sense -- the report allocated
by HID core in hid_hw_raw_request() can be much larger than
DJREPORT_SHORT_LENGTH, and currently logi_dj_ll_raw_request() doesn't
handle this properly at all.

Fix the check by actually trimming down the report size properly if it is
too large.

Reported-by: Ben Hawkes <hawkes@xxxxxxxxxx>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

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

--- a/drivers/hid/hid-logitech-dj.c
+++ b/drivers/hid/hid-logitech-dj.c
@@ -557,7 +557,7 @@ static int logi_dj_ll_raw_request(struct
if (!out_buf)
return -ENOMEM;

- if (count < DJREPORT_SHORT_LENGTH - 2)
+ if (count > DJREPORT_SHORT_LENGTH - 2)
count = DJREPORT_SHORT_LENGTH - 2;

out_buf[0] = REPORT_ID_DJ_SHORT;


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