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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 404EAC76190 for ; Tue, 23 Jul 2019 14:38:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 22C3721738 for ; Tue, 23 Jul 2019 14:38:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390646AbfGWOiM (ORCPT ); Tue, 23 Jul 2019 10:38:12 -0400 Received: from s3.sipsolutions.net ([144.76.43.62]:56514 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729771AbfGWOiM (ORCPT ); Tue, 23 Jul 2019 10:38:12 -0400 Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1hpvve-0007sr-Dp; Tue, 23 Jul 2019 16:38:10 +0200 From: Johannes Berg To: linux-wireless@vger.kernel.org Cc: Emmanuel Grumbach Subject: [PATCH 3/3] iwlwifi: mvm: fix a use-after-free bug in iwl_mvm_tx_tso_segment Date: Tue, 23 Jul 2019 16:38:03 +0200 Message-Id: <20190723143803.8698-4-johannes@sipsolutions.net> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190723143803.8698-1-johannes@sipsolutions.net> References: <20190723143803.8698-1-johannes@sipsolutions.net> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Emmanuel Grumbach Accessing the hdr of an skb that was consumed already isn't a good idea. First ask if the skb is a QoS packet, then keep that data on stack, and then consume the skb. This was spotted by KASAN. Fixes: 08f7d8b69aaf ("iwlwifi: mvm: bring back mvm GSO code") Signed-off-by: Emmanuel Grumbach Signed-off-by: Johannes Berg --- drivers/net/wireless/intel/iwlwifi/mvm/tx.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c index a3e5d88f1c07..6ac114a393cc 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c @@ -831,6 +831,7 @@ iwl_mvm_tx_tso_segment(struct sk_buff *skb, unsigned int num_subframes, unsigned int tcp_payload_len; unsigned int mss = skb_shinfo(skb)->gso_size; bool ipv4 = (skb->protocol == htons(ETH_P_IP)); + bool qos = ieee80211_is_data_qos(hdr->frame_control); u16 ip_base_id = ipv4 ? ntohs(ip_hdr(skb)->id) : 0; skb_shinfo(skb)->gso_size = num_subframes * mss; @@ -864,7 +865,7 @@ iwl_mvm_tx_tso_segment(struct sk_buff *skb, unsigned int num_subframes, if (tcp_payload_len > mss) { skb_shinfo(tmp)->gso_size = mss; } else { - if (ieee80211_is_data_qos(hdr->frame_control)) { + if (qos) { u8 *qc; if (ipv4) -- 2.20.1