From patchwork Fri Apr 22 14:52:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Wetzel X-Patchwork-Id: 567103 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 11C94C433EF for ; Fri, 22 Apr 2022 15:03:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1449144AbiDVPFv (ORCPT ); Fri, 22 Apr 2022 11:05:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47400 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1449156AbiDVPF1 (ORCPT ); Fri, 22 Apr 2022 11:05:27 -0400 X-Greylist: delayed 566 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Fri, 22 Apr 2022 08:02:00 PDT Received: from ns2.wdyn.eu (ns2.wdyn.eu [5.252.227.236]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C4EDD5D64E; Fri, 22 Apr 2022 08:02:00 -0700 (PDT) From: Alexander Wetzel DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=wetzel-home.de; s=wetzel-home; t=1650639152; bh=GaoJjEeYtrkZYq4AFZT1+CvDCcuhrnUYGXMkfI7FpRQ=; h=From:To:Cc:Subject:Date; b=CzwZrV5NYZL8KIzCM80lEPB0a80IVCueADtEVEo9uBUEVg8EmD2lDnBRKGL3r+Z8o 5S5mdhPakWfCJItvRs08fROhG85iWAsV715NDOvLFcvnk/HL6a/SnuT4ztipDUmFpQ bebjjXoAlKOM3jkhvN7xSI6T0SiOgcMESUb9RuTU= To: linux-wireless@vger.kernel.org Cc: Alexander Wetzel , stable@vger.kernel.org, pa@panix.com Subject: [PATCH] rtl8180: Prevent using not initialized queues Date: Fri, 22 Apr 2022 16:52:28 +0200 Message-Id: <20220422145228.7567-1-alexander@wetzel-home.de> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Using not existing queues can panic the kernel with rtl8180/rtl8185 cards. Ignore the skb priority for those cards, they only have one tx queue. Cc: stable@vger.kernel.org Reported-by: pa@panix.com Tested-by: pa@panix.com Signed-off-by: Alexander Wetzel --- Pierre Asselin (pa@panix.com) reported a kernel crash in the Gentoo forum: https://forums.gentoo.org/viewtopic-t-1147832-postdays-0-postorder-asc-start-25.html He also confirmed that this patch fixes the issue. In summary this happened: After updating wpa_supplicant from 2.9 to 2.10 the kernel crashed with a "divide error: 0000" when connecting to an AP. Control port tx now tries to use IEEE80211_AC_VO for the priority, which wpa_supplicants starts to use in 2.10. Since only the rtl8187se part of the driver supports QoS, the priority of the skb is set to IEEE80211_AC_BE (2) by mac80211 for rtl8180/rtl8185 cards. rtl8180 is then unconditionally reading out the priority and finally crashes on drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c line 544 without this patch: idx = (ring->idx + skb_queue_len(&ring->queue)) % ring->entries "ring->entries" is zero for rtl8180/rtl8185 cards, tx_ring[2] never got initialized. drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c b/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c index 2477e18c7cae..025619cd14e8 100644 --- a/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c +++ b/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c @@ -460,8 +460,10 @@ static void rtl8180_tx(struct ieee80211_hw *dev, struct rtl8180_priv *priv = dev->priv; struct rtl8180_tx_ring *ring; struct rtl8180_tx_desc *entry; + unsigned int prio = 0; unsigned long flags; - unsigned int idx, prio, hw_prio; + unsigned int idx, hw_prio; + dma_addr_t mapping; u32 tx_flags; u8 rc_flags; @@ -470,7 +472,9 @@ static void rtl8180_tx(struct ieee80211_hw *dev, /* do arithmetic and then convert to le16 */ u16 frame_duration = 0; - prio = skb_get_queue_mapping(skb); + /* rtl8180/rtl8185 only has one useable tx queue */ + if (dev->queues > IEEE80211_AC_BK) + prio = skb_get_queue_mapping(skb); ring = &priv->tx_ring[prio]; mapping = dma_map_single(&priv->pdev->dev, skb->data, skb->len,