linux-kernel - [PATCH] platform/chrome: Fix locking pattern in wilco_ec

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-next>] [day] [month] [year] [list]

Date:   Mon, 11 Mar 2019 09:58:38 -0600
From:   Nick Crews <ncrews@...omium.org>
To:     enric.balletbo@...labora.com, bleung@...omium.org
Cc:     linux-kernel@...r.kernel.org, dlaurie@...omium.org,
        groeck@...gle.com, dtor@...gle.com,
        Nick Crews <ncrews@...omium.org>
Subject: [PATCH] platform/chrome: Fix locking pattern in wilco_ec_mailbox()

Before, ec->data_buffer could be written to from multiple
contexts at the same time. Since the ec is shared data,
it needs to be inside the mutex as well.

Signed-off-by: Nick Crews <ncrews@...omium.org>
---
 drivers/platform/chrome/wilco_ec/mailbox.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/chrome/wilco_ec/mailbox.c b/drivers/platform/chrome/wilco_ec/mailbox.c
index f6ff29a11f1a..d6cb96168285 100644
--- a/drivers/platform/chrome/wilco_ec/mailbox.c
+++ b/drivers/platform/chrome/wilco_ec/mailbox.c
@@ -223,12 +223,12 @@ int wilco_ec_mailbox(struct wilco_ec_device *ec, struct wilco_ec_message *msg)
 		msg->command, msg->type, msg->flags, msg->response_size,
 		msg->request_size);
 
-	/* Prepare request packet */
+	mutex_lock(&ec->mailbox_lock);
+
 	rq = ec->data_buffer;
 	wilco_ec_prepare(msg, rq);
-
-	mutex_lock(&ec->mailbox_lock);
 	ret = wilco_ec_transfer(ec, msg, rq);
+	
 	mutex_unlock(&ec->mailbox_lock);
 
 	return ret;
--