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 CD55BC4332F for ; Mon, 1 Nov 2021 09:31:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B33BC61504 for ; Mon, 1 Nov 2021 09:31:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232742AbhKAJe0 (ORCPT ); Mon, 1 Nov 2021 05:34:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:37292 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232942AbhKAJa0 (ORCPT ); Mon, 1 Nov 2021 05:30:26 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2BEE1610D2; Mon, 1 Nov 2021 09:23:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1635758639; bh=sEOdmsuzoGP6wtd5/Ft4943gT169+eqDJrfi3Jc685g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BV31vpHCU2UbGEmWMS4pxbNVf986fPkLQbM6jYKzc6cgii7ZfcWsi/EWjYrwJbIpf UcsjwL0M4C33O5sZXBvqAvqaE+vQpNq2YwOB5rupITrb/WfPY1cAxgQUEDlVufs+ir XMfOGogBlix8UKSY/TXNiQ6V4xssZ/xw4TsQgaCo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Johannes Berg Subject: [PATCH 5.4 20/51] cfg80211: scan: fix RCU in cfg80211_add_nontrans_list() Date: Mon, 1 Nov 2021 10:17:24 +0100 Message-Id: <20211101082505.200852489@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211101082500.203657870@linuxfoundation.org> References: <20211101082500.203657870@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 a2083eeb119fb9307258baea9b7c243ca9a2e0b6 upstream. The SSID pointer is pointing to RCU protected data, so we need to have it under rcu_read_lock() for the entire use. Fix this. Cc: stable@vger.kernel.org Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning") Link: https://lore.kernel.org/r/20210930131120.6ddfc603aa1d.I2137344c4e2426525b1a8e4ce5fca82f8ecbfe7e@changeid Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- net/wireless/scan.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -379,14 +379,17 @@ cfg80211_add_nontrans_list(struct cfg802 } ssid_len = ssid[1]; ssid = ssid + 2; - rcu_read_unlock(); /* check if nontrans_bss is in the list */ list_for_each_entry(bss, &trans_bss->nontrans_list, nontrans_list) { - if (is_bss(bss, nontrans_bss->bssid, ssid, ssid_len)) + if (is_bss(bss, nontrans_bss->bssid, ssid, ssid_len)) { + rcu_read_unlock(); return 0; + } } + rcu_read_unlock(); + /* add to the list */ list_add_tail(&nontrans_bss->nontrans_list, &trans_bss->nontrans_list); return 0;