From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-564561-1519835407-2-4916568111738442061 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.249, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES ensk.us-asciiro, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='uk', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1519835406; b=Bre/jTPDBowE9nI8KMTJ2Mp3obr7VOssF73ux0MQCjRUehF pi+Vw6jHqFA9fqkHpusdgmBtcpZ9N+d9mww4v9Y7hbtuZ7FscisVZPgOmtYiJAUD b2k+6TWQAw8b/ID9aNad3CUSjqqjVLhSeGWZW4vcWa5l8q534rdHhnhpkuW8jLm+ iHXAnhtEsklHVvdSbuFucDLC9H7ZgjAfRUOVjyp4E84B9eoEDewd38C64IKEZY9t Grs6gv2rcc7fXD5CaSCr887PtzS8G0CSF/vcFc2w3/4eVcBeNElQedH1Cc9Azvpp lptKzTbQCHXCYZJvLrVKi/rozhMpyRSKO4uF5AQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=content-type:content-transfer-encoding :mime-version:from:to:cc:date:message-id:subject:in-reply-to :sender:list-id; s=arctest; t=1519835406; bh=xGRDG/rNXxTH3arx1/x TgY2CJu8mOxxQPr8UB6Mr+MU=; b=trXngOT2xlIBQVOmRRQk10RakxXWiz4oai9 R5iEDuM/n5aRyo7BQxcJGp+aqWt2unKLVj07uCQt+YWv9G2TLF7ku2oYKtA5L53A PMXvIew78EzCt7eY9lbT2lUvSGFNFlr3FxJmjGqRmxsr8ErSCPN22V/rtJ5AQETR 8QOVzVIAqcc3TEjJid0NWyolYLN0XSmnxqE8BELDZVH2Vz4IJPsTVfc+YlRv6Ss2 VV0EoYYIRMp4+Mx+T8nwVGqh1UgtyU1+67P7Xucsnzt2+yKKDcwViXUaHm9nJtki l/C14MJxu1YEUK9vbYQq5N6057oCKZ4HuRbSwbptOX7K28QSUXw== ARC-Authentication-Results: i=1; mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=decadent.org.uk header.result=pass header_is_org_domain=yes Authentication-Results: mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=decadent.org.uk header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933348AbeB1Q3z (ORCPT ); Wed, 28 Feb 2018 11:29:55 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35170 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934792AbeB1QPU (ORCPT ); Wed, 28 Feb 2018 11:15:20 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Dominik Brodowski" , "Johannes Berg" Date: Wed, 28 Feb 2018 15:20:18 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 205/254] nl80211: take RCU read lock when calling ieee80211_bss_get_ie() In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 3.16.55-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Dominik Brodowski commit 7a94b8c2eee7083ddccd0515830f8c81a8e44b1a upstream. As ieee80211_bss_get_ie() derefences an RCU to return ssid_ie, both the call to this function and any operation on this variable need protection by the RCU read lock. Fixes: 44905265bc15 ("nl80211: don't expose wdev->ssid for most interfaces") Signed-off-by: Dominik Brodowski Signed-off-by: Johannes Berg Signed-off-by: Ben Hutchings --- net/wireless/nl80211.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -2354,12 +2354,13 @@ static int nl80211_send_iface(struct sk_ const u8 *ssid_ie; if (!wdev->current_bss) break; + rcu_read_lock(); ssid_ie = ieee80211_bss_get_ie(&wdev->current_bss->pub, WLAN_EID_SSID); - if (!ssid_ie) - break; - if (nla_put(msg, NL80211_ATTR_SSID, ssid_ie[1], ssid_ie + 2)) - goto nla_put_failure_locked; + if (ssid_ie && + nla_put(msg, NL80211_ATTR_SSID, ssid_ie[1], ssid_ie + 2)) + goto nla_put_failure_rcu_locked; + rcu_read_unlock(); break; } default: @@ -2370,6 +2371,8 @@ static int nl80211_send_iface(struct sk_ return genlmsg_end(msg, hdr); + nla_put_failure_rcu_locked: + rcu_read_unlock(); nla_put_failure_locked: wdev_unlock(wdev); nla_put_failure: