From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754181AbcLTCiW (ORCPT ); Mon, 19 Dec 2016 21:38:22 -0500 Received: from mail-oi0-f67.google.com ([209.85.218.67]:33206 "EHLO mail-oi0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751693AbcLTCiU (ORCPT ); Mon, 19 Dec 2016 21:38:20 -0500 From: Larry Finger To: kvalo@codeaurora.org, Linus Torvalds Cc: devel@driverdev.osuosl.org, linux-wireless@vger.kernel.org, Larry Finger , linux-kernel@vger.kernel.org, driver-devel@vger.kernel.org, Stable , Wei Yongjun Subject: [PATCH] rtlwifi: Fix kernel oops introduced with commit e49656147359 Date: Mon, 19 Dec 2016 20:38:12 -0600 Message-Id: <20161220023812.5999-1-Larry.Finger@lwfinger.net> X-Mailer: git-send-email 2.10.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org With commit e49656147359 {"rtlwifi: Use dev_kfree_skb_irq instead of kfree_skb"), the method used to free an skb was changed because the kfree_skb() was inside a spinlock. What was forgotten is that kfree_skb() guards against a NULL value for the argument. Routine dev_kfree_skb_irq() does not, and a test is needed to prevent kernel panics. Fixes: commit e49656147359 {"rtlwifi: Use dev_kfree_skb_irq instead of kfree_skb") Signed-off-by: Larry Finger Cc: Stable (4.9+) Cc: Wei Yongjun --- Kalle, This change should be sent to mainline during the 4.10 merge period, or as soon as possible. Thanks, Larry --- drivers/net/wireless/realtek/rtlwifi/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/realtek/rtlwifi/core.c b/drivers/net/wireless/realtek/rtlwifi/core.c index 955055b..df8b977 100644 --- a/drivers/net/wireless/realtek/rtlwifi/core.c +++ b/drivers/net/wireless/realtek/rtlwifi/core.c @@ -1823,7 +1823,8 @@ bool rtl_cmd_send_packet(struct ieee80211_hw *hw, struct sk_buff *skb) spin_lock_irqsave(&rtlpriv->locks.irq_th_lock, flags); pskb = __skb_dequeue(&ring->queue); - dev_kfree_skb_irq(pskb); + if (pskb) + dev_kfree_skb_irq(pskb); /*this is wrong, fill_tx_cmddesc needs update*/ pdesc = &ring->desc[0]; -- 2.10.2