From patchwork Thu May 26 13:35:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ryder Lee X-Patchwork-Id: 12862436 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 51D50C433F5 for ; Thu, 26 May 2022 13:35:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:CC :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=0qweVt4rAa/shUVkksYFulU5rCk2bZo2wL5GgMhCdqo=; b=VKYSDeATJpalot dZY0d2Mtw8PYArQFyVgEMm4iDsXEn3GGiGwyR5p2TpWvyUte4t9PpEJ3fNUrgdtqYCs6XWZqyGbAQ AH/7Jgb4dlJ4z5LHVODZWXG/RX2mGiM3adywoqZO+lSWKyHCjOexzKGwHLY6e1AcUQl9l1l81wvrz pTfP6R9ypAca8qs++ouEg3wXvFSYKg1jT1dKsfy64ccbl9nQ/K+gjV4BCrwzDoTQm7aNFyCOmecpI 755/vAH76XE9ZNVNs5plteyaDQXYWS2rJAf6D7iMbGbSYoHcEe3fYFerO0UBLUGAwmOekzNXfZ1bS tT5gcxwzOmb9b4yVAF9g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nuDeT-00F2f2-QV; Thu, 26 May 2022 13:35:45 +0000 Received: from mailgw01.mediatek.com ([216.200.240.184]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nuDeR-00F2eY-Iy for linux-mediatek@lists.infradead.org; Thu, 26 May 2022 13:35:45 +0000 X-UUID: 2e2b24e439c74ac792879d758aaebecd-20220526 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.5,REQID:0925ec76-62b7-4b7c-9dac-cf58af4abad9,OB:0,LO B:0,IP:0,URL:0,TC:0,Content:0,EDM:0,RT:0,SF:0,FILE:0,RULE:Release_Ham,ACTI ON:release,TS:0 X-CID-META: VersionHash:2a19b09,CLOUDID:f5b99847-4fb1-496b-8f1d-39e733fed1ea,C OID:IGNORED,Recheck:0,SF:nil,TC:nil,Content:0,EDM:-3,IP:nil,URL:0,File:nil ,QS:0,BEC:nil X-UUID: 2e2b24e439c74ac792879d758aaebecd-20220526 Received: from mtkcas66.mediatek.inc [(172.29.193.44)] by mailgw01.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 1483376012; Thu, 26 May 2022 06:35:35 -0700 Received: from mtkmbs11n1.mediatek.inc (172.21.101.185) by MTKMBS62N2.mediatek.inc (172.29.193.42) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 26 May 2022 06:35:33 -0700 Received: from mtkmbs11n1.mediatek.inc (172.21.101.185) by mtkmbs11n1.mediatek.inc (172.21.101.185) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.792.3; Thu, 26 May 2022 21:35:32 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkmbs11n1.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.792.3 via Frontend Transport; Thu, 26 May 2022 21:35:32 +0800 From: Ryder Lee To: CC: Felix Fietkau , Lorenzo Bianconi , Shayne Chen , "Evelyn Tsai" , , "Ryder Lee" Subject: [PATCH v2] mac80211: check skb_shared in ieee80211_8023_xmit() Date: Thu, 26 May 2022 21:35:32 +0800 Message-ID: X-Mailer: git-send-email 2.18.0 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220526_063543_671985_7AAEBB19 X-CRM114-Status: GOOD ( 13.28 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org Add a missing skb_shared check into 802.3 path to prevent potential use-after-free from happening. This also uses skb_share_check() instead of open-coding in tx path. Signed-off-by: Ryder Lee --- change since v2 - switch to use skb_share_check() --- net/mac80211/tx.c | 36 +++++++++++++----------------------- 1 file changed, 13 insertions(+), 23 deletions(-) diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 0e4efc08c762..c425f4fb7c2e 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -2818,19 +2818,10 @@ static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata, /* * If the skb is shared we need to obtain our own copy. */ - if (skb_shared(skb)) { - struct sk_buff *tmp_skb = skb; - - /* can't happen -- skb is a clone if info_id != 0 */ - WARN_ON(info_id); - - skb = skb_clone(skb, GFP_ATOMIC); - kfree_skb(tmp_skb); - - if (!skb) { - ret = -ENOMEM; - goto free; - } + skb = skb_share_check(skb, GFP_ATOMIC); + if (unlikely(!skb)) { + ret = -ENOMEM; + goto free; } hdr.frame_control = fc; @@ -3539,15 +3530,9 @@ static bool ieee80211_xmit_fast(struct ieee80211_sub_if_data *sdata, /* after this point (skb is modified) we cannot return false */ - if (skb_shared(skb)) { - struct sk_buff *tmp_skb = skb; - - skb = skb_clone(skb, GFP_ATOMIC); - kfree_skb(tmp_skb); - - if (!skb) - return true; - } + skb = skb_share_check(skb, GFP_ATOMIC); + if (unlikely(!skb)) + return true; if ((hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) && ieee80211_amsdu_aggregate(sdata, sta, fast_tx, skb)) @@ -4437,7 +4422,7 @@ static void ieee80211_8023_xmit(struct ieee80211_sub_if_data *sdata, struct net_device *dev, struct sta_info *sta, struct ieee80211_key *key, struct sk_buff *skb) { - struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + struct ieee80211_tx_info *info; struct ieee80211_local *local = sdata->local; struct tid_ampdu_tx *tid_tx; u8 tid; @@ -4452,6 +4437,11 @@ static void ieee80211_8023_xmit(struct ieee80211_sub_if_data *sdata, test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state)) goto out_free; + skb = skb_share_check(skb, GFP_ATOMIC); + if (unlikely(!skb)) + return; + + info = IEEE80211_SKB_CB(skb); memset(info, 0, sizeof(*info)); ieee80211_aggr_check(sdata, sta, skb);