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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B338FC433F5 for ; Mon, 4 Oct 2021 13:14:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9FE9463222 for ; Mon, 4 Oct 2021 13:14:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236230AbhJDNQ3 (ORCPT ); Mon, 4 Oct 2021 09:16:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:54104 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235489AbhJDNO3 (ORCPT ); Mon, 4 Oct 2021 09:14:29 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3B37861A03; Mon, 4 Oct 2021 13:05:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1633352746; bh=9DB9ESAOJ1QB5v+g5UT2LVVrpoNPdfYcg2nLYbholQA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yqIoKuofJQsyTMZ51Z7YXeSmOLyMtD50PiycbBzlARdxeOB+yhHavXByT5M+TBsP8 /fFlo8hwLn/wEyqz3x5rAcEKZx0y6EBqj/Rf0Pep/xHRMoXSNisKzuHq+iSR1JDelp nE161aU9wnxVFaAlLFXGRZJ4hA22l9jGKViNvM40= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Johannes Berg Subject: [PATCH 5.4 10/56] mac80211: fix use-after-free in CCMP/GCMP RX Date: Mon, 4 Oct 2021 14:52:30 +0200 Message-Id: <20211004125030.337411814@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211004125030.002116402@linuxfoundation.org> References: <20211004125030.002116402@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Johannes Berg commit 94513069eb549737bcfc3d988d6ed4da948a2de8 upstream. When PN checking is done in mac80211, for fragmentation we need to copy the PN to the RX struct so we can later use it to do a comparison, since commit bf30ca922a0c ("mac80211: check defrag PN against current frame"). Unfortunately, in that commit I used the 'hdr' variable without it being necessarily valid, so use-after-free could occur if it was necessary to reallocate (parts of) the frame. Fix this by reloading the variable after the code that results in the reallocations, if any. This fixes https://bugzilla.kernel.org/show_bug.cgi?id=214401. Cc: stable@vger.kernel.org Fixes: bf30ca922a0c ("mac80211: check defrag PN against current frame") Link: https://lore.kernel.org/r/20210927115838.12b9ac6bb233.I1d066acd5408a662c3b6e828122cd314fcb28cdb@changeid Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- net/mac80211/wpa.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/net/mac80211/wpa.c +++ b/net/mac80211/wpa.c @@ -520,6 +520,9 @@ ieee80211_crypto_ccmp_decrypt(struct iee return RX_DROP_UNUSABLE; } + /* reload hdr - skb might have been reallocated */ + hdr = (void *)rx->skb->data; + data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - mic_len; if (!rx->sta || data_len < 0) return RX_DROP_UNUSABLE; @@ -749,6 +752,9 @@ ieee80211_crypto_gcmp_decrypt(struct iee return RX_DROP_UNUSABLE; } + /* reload hdr - skb might have been reallocated */ + hdr = (void *)rx->skb->data; + data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - mic_len; if (!rx->sta || data_len < 0) return RX_DROP_UNUSABLE;