HID: i2c-hid: fix size check and type usage

BugLink: http://bugs.launchpad.net/bugs/1773233
commit ac75a041048b8c1f7418e27621ca5efda8571043 upstream.

When convert char array with signed int, if the inbuf[x] is negative then
upper bits will be set to 1. Fix this by using u8 instead of char.

ret_size has to be at least 3, hid_input_report use it after minus 2 bytes.

Cc: stable@vger.kernel.org
Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Acked-by: Khalid Elmously <khalid.elmously@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
index e054ee43c1e275da0adff1d6ee5e8ec49bb1ecbc..d17d1950392ba28a1e5fac4f7159f6b951017254 100644 (file)
--- a/drivers/hid/i2c-hid/i2c-hid.c
+++ b/drivers/hid/i2c-hid/i2c-hid.c
@@ -144,10 +144,10 @@ struct i2c_hid {
                                                   * register of the HID
                                                   * descriptor. */
        unsigned int            bufsize;        /* i2c buffer size */
-       char                    *inbuf;         /* Input buffer */
-       char                    *rawbuf;        /* Raw Input buffer */
-       char                    *cmdbuf;        /* Command buffer */
-       char                    *argsbuf;       /* Command arguments buffer */
+       u8                      *inbuf;         /* Input buffer */
+       u8                      *rawbuf;        /* Raw Input buffer */
+       u8                      *cmdbuf;        /* Command buffer */
+       u8                      *argsbuf;       /* Command arguments buffer */
 
        unsigned long           flags;          /* device flags */
        unsigned long           quirks;         /* Various quirks */
@@ -455,7 +455,8 @@ out_unlock:
 
 static void i2c_hid_get_input(struct i2c_hid *ihid)
 {
-       int ret, ret_size;
+       int ret;
+       u32 ret_size;
        int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 
        if (size > ihid->bufsize)
@@ -480,7 +481,7 @@ static void i2c_hid_get_input(struct i2c_hid *ihid)
                return;
        }
 
-       if (ret_size > size) {
+       if ((ret_size > size) || (ret_size <= 2)) {
                dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
                        __func__, size, ret_size);
                return;