This is a note to let you know that I've just added the patch titled

    HID: i2c-hid: Limit reads to wMaxInputLength bytes for input events

to the 3.18-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     hid-i2c-hid-limit-reads-to-wmaxinputlength-bytes-for-input-events.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From 6d00f37e49d95e640a3937a4a1ae07dbe92a10cb Mon Sep 17 00:00:00 2001
From: Seth Forshee <[email protected]>
Date: Fri, 20 Feb 2015 11:45:11 -0600
Subject: HID: i2c-hid: Limit reads to wMaxInputLength bytes for input events

From: Seth Forshee <[email protected]>

commit 6d00f37e49d95e640a3937a4a1ae07dbe92a10cb upstream.

d1c7e29e8d27 (HID: i2c-hid: prevent buffer overflow in early IRQ)
changed hid_get_input() to read ihid->bufsize bytes, which can be
more than wMaxInputLength. This is the case with the Dell XPS 13
9343, and it is causing events to be missed. In some cases the
missed events are releases, which can cause the cursor to jump or
freeze, among other problems. Limit the number of bytes read to
min(wMaxInputLength, ihid->bufsize) to prevent such problems.

Fixes: d1c7e29e8d27 "HID: i2c-hid: prevent buffer overflow in early IRQ"
Signed-off-by: Seth Forshee <[email protected]>
Reviewed-by: Benjamin Tissoires <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 drivers/hid/i2c-hid/i2c-hid.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/hid/i2c-hid/i2c-hid.c
+++ b/drivers/hid/i2c-hid/i2c-hid.c
@@ -370,7 +370,10 @@ static int i2c_hid_hwreset(struct i2c_cl
 static void i2c_hid_get_input(struct i2c_hid *ihid)
 {
        int ret, ret_size;
-       int size = ihid->bufsize;
+       int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
+
+       if (size > ihid->bufsize)
+               size = ihid->bufsize;
 
        ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
        if (ret != size) {


Patches currently in stable-queue which might be from 
[email protected] are

queue-3.18/hid-i2c-hid-limit-reads-to-wmaxinputlength-bytes-for-input-events.patch
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