Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754484AbdFSSlM (ORCPT + 2 others); Mon, 19 Jun 2017 14:41:12 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:52802 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754090AbdFSSlK (ORCPT ); Mon, 19 Jun 2017 14:41:10 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Arnd Bergmann , Kalle Valo , Willy Tarreau Subject: [PATCH 3.10 251/268] hostap: avoid uninitialized variable use in hfa384x_get_rid Date: Mon, 19 Jun 2017 20:32:30 +0200 Message-Id: <1497897167-14556-252-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1497897167-14556-1-git-send-email-w@1wt.eu> References: <1497897167-14556-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: From: Arnd Bergmann commit 48dc5fb3ba53b20418de8514700f63d88c5de3a3 upstream. 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 Signed-off-by: Kalle Valo Signed-off-by: Willy Tarreau --- drivers/net/wireless/hostap/hostap_hw.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/net/wireless/hostap/hostap_hw.c b/drivers/net/wireless/hostap/hostap_hw.c index 6307a4e..f863900 100644 --- a/drivers/net/wireless/hostap/hostap_hw.c +++ b/drivers/net/wireless/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); -- 2.8.0.rc2.1.gbe9624a