From patchwork Thu Jan 28 21:58:28 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 101047 Delivered-To: patch@linaro.org Received: by 10.112.130.2 with SMTP id oa2csp744820lbb; Thu, 28 Jan 2016 13:59:12 -0800 (PST) X-Received: by 10.98.16.72 with SMTP id y69mr8119314pfi.95.1454018352393; Thu, 28 Jan 2016 13:59:12 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id tw5si19274466pac.131.2016.01.28.13.59.12; Thu, 28 Jan 2016 13:59:12 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966853AbcA1V7K (ORCPT + 30 others); Thu, 28 Jan 2016 16:59:10 -0500 Received: from mout.kundenserver.de ([217.72.192.74]:64996 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932198AbcA1V7H (ORCPT ); Thu, 28 Jan 2016 16:59:07 -0500 Received: from wuerfel.localnet ([78.42.132.4]) by mrelayeu.kundenserver.de (mreue103) with ESMTPSA (Nemesis) id 0LrHzA-1ZxMou3OF2-0139Lo; Thu, 28 Jan 2016 22:58:32 +0100 From: Arnd Bergmann To: Kalle Valo Cc: Jouni Malinen , netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Arnd Bergmann , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Russell King - ARM Linux Subject: [PATCH v2] hostap: avoid uninitialized variable use in hfa384x_get_rid Date: Thu, 28 Jan 2016 22:58:28 +0100 Message-ID: <18181682.hKPVvnQWXk@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.16.0-10-generic; KDE/4.11.5; x86_64; ; ) MIME-Version: 1.0 X-Provags-ID: V03:K0:+fLE6ZLJpRJNwY13FjrJRa/VLY7Ejhflsk7Z9tI0sVff1Si7TkF HWPIH+8Jcfukscpjdk7Qkz1mBVvGpY0eblCwVd51eXn2iiSjhLiCbyJeSDKPso8ASqULhh3 SfI2SU01nCbu9/wFHCg63tM7M53DpAzW8SGAzpU0tYbNfiPoNrImaIXiQhiAtIHYPjw71Z3 /jnZ90PwSUR6XCmaGt5zA== X-UI-Out-Filterresults: notjunk:1; V01:K0:ymIHlINYfaM=:La5k+Tvmlei5rXa9AEEl3j ZlbiGCPqRD0HUt/SIB0DQVV8qocImfhN72VMKA92juIYKD5SVA+aNqN8xI7/CjWPZLfGsnZgn ccot3afDY5u15GLYyn2SY5+PB1odc33PM8Yp4IWkFjL8va3wFXFjNPV98mAtAfbFrDUud0ikp pwN31R8GIbiwTec94DApVxVkxOGC6h2MUWssifXS6LdxjMmOqT6gNWZOahjGW8htqUIybCE4B ZWXcLWfX0tYnTXURRG+Ei63B8elC5o4Wo8pz+/1lo2/yKfMyAQY1B8kdddqKw8gjlcmbXJtx5 sm4vDwFdawShstL19oIgMdT23echTiXoYYWixFYjZF2JbSuEQEowOwoszsHXR30ezjMACffHI FAU67IXLm4gentU/bhmRzqdIiEg/ZuwvJSQdLdAdFMXJ2QJkwSKh4hBt3CBzNg02W2Sv1bk4J 0w6BRK8uR3r1AZuBhY1hWeTSczNGoBPbOx0bNuv2/jf0hH/W3GdJYdXZ1hPe5psIH7YVWNlIg +TTXXwy3ienCA0LL+AlDlbKBr3ZW1utOuSjj5T0YZWJTpH8/88FERSXh5bbdgtxuDv2IFM6ke JhOrzFEfBtVi8f5ggPIG/HDnEWZlcVOYvMy5tECRMo0KKrN58R9CnTeVHTRpLrudg+hxVpiWC zUNSzPCLvROGoCk87z4TK7aqqnOOpog/yRPICnvHbvso5BnEh9Z+ZVMH/yMwhYbcSkFvwSMjB FWpOghsyCXnuutxi Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The driver reads a value from hfa384x_from_bap(), which may fail, and then assigns the value to a local variable. gcc detects that in in the failure case, the 'rlen' variable now contains uninitialized data: In file included from ../drivers/net/wireless/intersil/hostap/hostap_pci.c:220:0: drivers/net/wireless/intersil/hostap/hostap_hw.c: In function 'hfa384x_get_rid': drivers/net/wireless/intersil/hostap/hostap_hw.c:842:5: warning: 'rec' may be used uninitialized in this function [-Wmaybe-uninitialized] if (le16_to_cpu(rec.len) == 0) { This restructures the function as suggested by Russell King, to make it more readable and get more reliable error handling, by handling each failure mode using a goto. Signed-off-by: Arnd Bergmann diff --git a/drivers/net/wireless/intersil/hostap/hostap_hw.c b/drivers/net/wireless/intersil/hostap/hostap_hw.c index 6df3ee561d52..515aa3f993f3 100644 --- a/drivers/net/wireless/intersil/hostap/hostap_hw.c +++ b/drivers/net/wireless/intersil/hostap/hostap_hw.c @@ -836,25 +836,30 @@ static int hfa384x_get_rid(struct net_device *dev, u16 rid, void *buf, int len, spin_lock_bh(&local->baplock); res = hfa384x_setup_bap(dev, BAP0, rid, 0); - if (!res) - res = hfa384x_from_bap(dev, BAP0, &rec, sizeof(rec)); + if (res) + goto unlock; + + res = hfa384x_from_bap(dev, BAP0, &rec, sizeof(rec)); + if (res) + goto unlock; if (le16_to_cpu(rec.len) == 0) { /* RID not available */ res = -ENODATA; + goto unlock; } rlen = (le16_to_cpu(rec.len) - 1) * 2; - if (!res && exact_len && rlen != len) { + if (exact_len && rlen != len) { printk(KERN_DEBUG "%s: hfa384x_get_rid - RID len mismatch: " "rid=0x%04x, len=%d (expected %d)\n", dev->name, rid, rlen, len); res = -ENODATA; } - if (!res) - res = hfa384x_from_bap(dev, BAP0, buf, len); + res = hfa384x_from_bap(dev, BAP0, buf, len); +unlock: spin_unlock_bh(&local->baplock); mutex_unlock(&local->rid_bap_mtx);