From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julia Lawall Subject: [PATCH 3/4] drivers/hid: Eliminate use after free Date: Sat, 15 May 2010 11:46:36 +0200 (CEST) Message-ID: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: Received: from mgw2.diku.dk ([130.225.96.92]:53951 "EHLO mgw2.diku.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752090Ab0EOJql (ORCPT ); Sat, 15 May 2010 05:46:41 -0400 Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Jiri Kosina , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org From: Julia Lawall The skip label frees resp, which has not been allocated at the point of this goto and then does a break, based on the fact that err is non-zero. This is replaced by a break directly. A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // @free@ expression E; position p; @@ kfree@p(E) @@ expression free.E, subE<=free.E, E1; position free.p; @@ kfree@p(E) ... ( subE = E1 | * E ) // Signed-off-by: Julia Lawall --- drivers/hid/hid-picolcd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hid/hid-picolcd.c b/drivers/hid/hid-picolcd.c index 95253b3..7aabf65 100644 --- a/drivers/hid/hid-picolcd.c +++ b/drivers/hid/hid-picolcd.c @@ -1616,7 +1616,7 @@ static ssize_t _picolcd_flash_write(struct picolcd_data *data, int report_id, raw_data[len_off] = s > 32 ? 32 : s; if (copy_from_user(raw_data+len_off+1, u, raw_data[len_off])) { err = -EFAULT; - goto skip; + break; } resp = picolcd_send_and_wait(data->hdev, report_id, raw_data, len_off+1+raw_data[len_off]);