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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 6F706ECDE43 for ; Thu, 18 Oct 2018 18:01:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 274C521476 for ; Thu, 18 Oct 2018 18:01:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="QAhjZZ+u" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 274C521476 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729672AbeJSCED (ORCPT ); Thu, 18 Oct 2018 22:04:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:52164 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729073AbeJSCEC (ORCPT ); Thu, 18 Oct 2018 22:04:02 -0400 Received: from localhost (ip-213-127-77-176.ip.prioritytelecom.net [213.127.77.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CE15021480; Thu, 18 Oct 2018 18:01:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539885716; bh=Rl48ME+C+ezw/eMoNs40vSBWhuO5d++ZTBQoIO2OpBE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QAhjZZ+uvdibRRmY+tzc1qHgGPWMmOQhZXugbgXrpo7ZrlygEmWo2Qh6hlnQ8AWb6 MB+h5qBEK+rxenN7b8hIPgckklCpfwuJhF3tRlzx969yNAiR+hxFj3pd9se4ojvslI MGxiizpVjXSP0UqcyRiH2hR9bTmpqRuolB+ngeNU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sven Eckelmann , Simon Wunderlich , Sasha Levin Subject: [PATCH 4.14 08/41] batman-adv: Prevent duplicated global TT entry Date: Thu, 18 Oct 2018 19:54:23 +0200 Message-Id: <20181018175418.332222705@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181018175416.718399607@linuxfoundation.org> References: <20181018175416.718399607@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sven Eckelmann [ Upstream commit e7136e48ffdfb9f37b0820f619380485eb407361 ] The function batadv_tt_global_orig_entry_add is responsible for adding new tt_orig_list_entry to the orig_list. It first checks whether the entry already is in the list or not. If it is, then the creation of a new entry is aborted. But the lock for the list is only held when the list is really modified. This could lead to duplicated entries because another context could create an entry with the same key between the check and the list manipulation. The check and the manipulation of the list must therefore be in the same locked code section. Fixes: d657e621a0f5 ("batman-adv: add reference counting for type batadv_tt_orig_list_entry") Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/batman-adv/translation-table.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -1587,6 +1587,8 @@ batadv_tt_global_orig_entry_add(struct b { struct batadv_tt_orig_list_entry *orig_entry; + spin_lock_bh(&tt_global->list_lock); + orig_entry = batadv_tt_global_orig_entry_find(tt_global, orig_node); if (orig_entry) { /* refresh the ttvn: the current value could be a bogus one that @@ -1609,11 +1611,9 @@ batadv_tt_global_orig_entry_add(struct b orig_entry->flags = flags; kref_init(&orig_entry->refcount); - spin_lock_bh(&tt_global->list_lock); kref_get(&orig_entry->refcount); hlist_add_head_rcu(&orig_entry->list, &tt_global->orig_list); - spin_unlock_bh(&tt_global->list_lock); atomic_inc(&tt_global->orig_list_count); sync_flags: @@ -1621,6 +1621,8 @@ sync_flags: out: if (orig_entry) batadv_tt_orig_list_entry_put(orig_entry); + + spin_unlock_bh(&tt_global->list_lock); } /**