[PATCH] HID: logitech: fix bounds checking on LED report size

From: Jiri Kosina
Date: Thu Aug 21 2014 - 11:42:08 EST


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.

Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Ben Hawkes <hawkes@xxxxxxxxxx>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
---
drivers/hid/hid-logitech-dj.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c
index 486dbde..ca0ab51 100644
--- 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 hid_device *hid,
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;

--
Jiri Kosina
SUSE Labs
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