linux-kernel - [ 31/94] HID: wiimote: Fix IR data parser

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sun, 27 May 2012 10:04:54 +0900
From:	Greg KH <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:	torvalds@...ux-foundation.org, akpm@...ux-foundation.org,
	alan@...rguk.ukuu.org.uk,
	Peter Bukovsky <bukovsky.peter@...il.com>,
	David Herrmann <dh.herrmann@...glemail.com>,
	Jiri Kosina <jkosina@...e.cz>
Subject: [ 31/94] HID: wiimote: Fix IR data parser

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

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

From: David Herrmann <dh.herrmann@...glemail.com>

commit 74b89e8a3625c17c7452532dfb997ac4f1a38751 upstream.

We incorrectly parse incoming IR data. The extra byte contains the upper
bits and not the lower bits of the x/y coordinates. User-space expects
absolute position data from us so this patch does not break existing
applications. On the contrary, it extends the virtual view and fixes
garbage reports for margin areas of the virtual screen.

Reported-by: Peter Bukovsky <bukovsky.peter@...il.com>
Signed-off-by: David Herrmann <dh.herrmann@...glemail.com>
Signed-off-by: Jiri Kosina <jkosina@...e.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/hid/hid-wiimote-core.c |   16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

--- a/drivers/hid/hid-wiimote-core.c
+++ b/drivers/hid/hid-wiimote-core.c
@@ -769,7 +769,7 @@ static void __ir_to_input(struct wiimote
 
 	/*
 	 * Basic IR data is encoded into 3 bytes. The first two bytes are the
-	 * upper 8 bit of the X/Y data, the 3rd byte contains the lower 2 bits
+	 * lower 8 bit of the X/Y data, the 3rd byte contains the upper 2 bits
 	 * of both.
 	 * If data is packed, then the 3rd byte is put first and slightly
 	 * reordered. This allows to interleave packed and non-packed data to
@@ -778,17 +778,11 @@ static void __ir_to_input(struct wiimote
 	 */
 
 	if (packed) {
-		x = ir[1] << 2;
-		y = ir[2] << 2;
-
-		x |= ir[0] & 0x3;
-		y |= (ir[0] >> 2) & 0x3;
+		x = ir[1] | ((ir[0] & 0x03) << 8);
+		y = ir[2] | ((ir[0] & 0x0c) << 6);
 	} else {
-		x = ir[0] << 2;
-		y = ir[1] << 2;
-
-		x |= (ir[2] >> 4) & 0x3;
-		y |= (ir[2] >> 6) & 0x3;
+		x = ir[0] | ((ir[2] & 0x30) << 4);
+		y = ir[1] | ((ir[2] & 0xc0) << 2);
 	}
 
 	input_report_abs(wdata->ir, xid, x);


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/