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From:   Ben Hutchings <ben@decadent.org.uk>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
CC:     akpm@linux-foundation.org,
        "Dan Carpenter" <dan.carpenter@oracle.com>,
        "Jiri Kosina" <jkosina@suse.cz>, "Silvan Jegen" <s.jegen@gmail.com>
Date:   Thu, 07 Jun 2018 15:05:21 +0100
Message-ID: <lsq.1528380321.214352537@decadent.org.uk>
Subject: [PATCH 3.16 162/410] HID: roccat: prevent an out of bounds read
 in kovaplus_profile_activated()
In-Reply-To: <lsq.1528380320.647747352@decadent.org.uk>
Sender: linux-kernel-owner@vger.kernel.org
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3.16.57-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Dan Carpenter <dan.carpenter@oracle.com>

commit 7ad81482cad67cbe1ec808490d1ddfc420c42008 upstream.

We get the "new_profile_index" value from the mouse device when we're
handling raw events.  Smatch taints it as untrusted data and complains
that we need a bounds check.  This seems like a reasonable warning
otherwise there is a small read beyond the end of the array.

Fixes: 0e70f97f257e ("HID: roccat: Add support for Kova[+] mouse")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Silvan Jegen <s.jegen@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 drivers/hid/hid-roccat-kovaplus.c | 2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/hid/hid-roccat-kovaplus.c
+++ b/drivers/hid/hid-roccat-kovaplus.c
@@ -37,6 +37,8 @@ static uint kovaplus_convert_event_cpi(u
 static void kovaplus_profile_activated(struct kovaplus_device *kovaplus,
 		uint new_profile_index)
 {
+	if (new_profile_index >= ARRAY_SIZE(kovaplus->profile_settings))
+		return;
 	kovaplus->actual_profile = new_profile_index;
 	kovaplus->actual_cpi = kovaplus->profile_settings[new_profile_index].cpi_startup_level;
 	kovaplus->actual_x_sensitivity = kovaplus->profile_settings[new_profile_index].sensitivity_x;