From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 921F2C65C20 for ; Mon, 8 Oct 2018 18:46:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 532D72087D for ; Mon, 8 Oct 2018 18:46:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="DzmiKFjN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 532D72087D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731222AbeJIB7e (ORCPT ); Mon, 8 Oct 2018 21:59:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:47788 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728570AbeJIB7d (ORCPT ); Mon, 8 Oct 2018 21:59:33 -0400 Received: from localhost (ip-213-127-77-176.ip.prioritytelecom.net [213.127.77.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4EC8E2064A; Mon, 8 Oct 2018 18:46:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539024386; bh=SzZjW4v4APK2ERSAK82BrxhrFlqcSzkJj//BHf/yRng=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DzmiKFjNO3CNrK9wFblHbGxchq2+CXHhYiMIcAsLhzEDe8Dd1o/T3UnyJXm4kiL75 wObepHQO7/ZQ2EE+on9g2llKY/o3PYXxTWP+RnGi8gwGZM+6mnclRq7diBXw+sBmcP P2Sc2Ow1sXD+6QNfEcoGjBjin0Q4vHA2cb5md4pU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sara Sharon , Lorenzo Bianconi , Johannes Berg , Sasha Levin Subject: [PATCH 4.18 024/168] mac80211: avoid kernel panic when building AMSDU from non-linear SKB Date: Mon, 8 Oct 2018 20:30:04 +0200 Message-Id: <20181008175620.961798766@linuxfoundation.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20181008175620.043587728@linuxfoundation.org> References: <20181008175620.043587728@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sara Sharon [ Upstream commit 166ac9d55b0ab70b644e429be1f217fe8393cbd7 ] When building building AMSDU from non-linear SKB, we hit a kernel panic when trying to push the padding to the tail. Instead, put the padding at the head of the next subframe. This also fixes the A-MSDU subframes to not have the padding accounted in the length field and not have pad at all for the last subframe, both required by the spec. Fixes: 6e0456b54545 ("mac80211: add A-MSDU tx support") Signed-off-by: Sara Sharon Reviewed-by: Lorenzo Bianconi Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/mac80211/tx.c | 38 +++++++++++++++++++++----------------- 1 file changed, 21 insertions(+), 17 deletions(-) --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -3073,27 +3073,18 @@ void ieee80211_clear_fast_xmit(struct st } static bool ieee80211_amsdu_realloc_pad(struct ieee80211_local *local, - struct sk_buff *skb, int headroom, - int *subframe_len) + struct sk_buff *skb, int headroom) { - int amsdu_len = *subframe_len + sizeof(struct ethhdr); - int padding = (4 - amsdu_len) & 3; - - if (skb_headroom(skb) < headroom || skb_tailroom(skb) < padding) { + if (skb_headroom(skb) < headroom) { I802_DEBUG_INC(local->tx_expand_skb_head); - if (pskb_expand_head(skb, headroom, padding, GFP_ATOMIC)) { + if (pskb_expand_head(skb, headroom, 0, GFP_ATOMIC)) { wiphy_debug(local->hw.wiphy, "failed to reallocate TX buffer\n"); return false; } } - if (padding) { - *subframe_len += padding; - skb_put_zero(skb, padding); - } - return true; } @@ -3117,8 +3108,7 @@ static bool ieee80211_amsdu_prepare_head if (info->control.flags & IEEE80211_TX_CTRL_AMSDU) return true; - if (!ieee80211_amsdu_realloc_pad(local, skb, sizeof(*amsdu_hdr), - &subframe_len)) + if (!ieee80211_amsdu_realloc_pad(local, skb, sizeof(*amsdu_hdr))) return false; data = skb_push(skb, sizeof(*amsdu_hdr)); @@ -3184,7 +3174,8 @@ static bool ieee80211_amsdu_aggregate(st void *data; bool ret = false; unsigned int orig_len; - int n = 1, nfrags; + int n = 1, nfrags, pad = 0; + u16 hdrlen; if (!ieee80211_hw_check(&local->hw, TX_AMSDU)) return false; @@ -3235,8 +3226,19 @@ static bool ieee80211_amsdu_aggregate(st if (max_frags && nfrags > max_frags) goto out; - if (!ieee80211_amsdu_realloc_pad(local, skb, sizeof(rfc1042_header) + 2, - &subframe_len)) + /* + * Pad out the previous subframe to a multiple of 4 by adding the + * padding to the next one, that's being added. Note that head->len + * is the length of the full A-MSDU, but that works since each time + * we add a new subframe we pad out the previous one to a multiple + * of 4 and thus it no longer matters in the next round. + */ + hdrlen = fast_tx->hdr_len - sizeof(rfc1042_header); + if ((head->len - hdrlen) & 3) + pad = 4 - ((head->len - hdrlen) & 3); + + if (!ieee80211_amsdu_realloc_pad(local, skb, sizeof(rfc1042_header) + + 2 + pad)) goto out; ret = true; @@ -3248,6 +3250,8 @@ static bool ieee80211_amsdu_aggregate(st memcpy(data, &len, 2); memcpy(data + 2, rfc1042_header, sizeof(rfc1042_header)); + memset(skb_push(skb, pad), 0, pad); + head->len += skb->len; head->data_len += skb->len; *frag_tail = skb;