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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 0719EC2BA83 for ; Thu, 13 Feb 2020 15:41:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C6D0E20661 for ; Thu, 13 Feb 2020 15:41:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581608472; bh=AzMvOGFeP02uYb2htvlWBAJwij+2RSgKQh/WezhmmP4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=FNIg3JT3jOxLCNwP0wO8jYP1o2dNKighe+hL2Y3/ok4UtEo6u0N0kMBqdcwq0GS8z MGus9lkZXQEVhnDD+SM1l/vUKNuyG8dZnhKM/rMRUd0hMDkHtLq02bg2Btotzj4ujO iEN1k30yDzG2Az4PS+Wg6f4L0TMHOTxDQwM3YG9Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387588AbgBMPlM (ORCPT ); Thu, 13 Feb 2020 10:41:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:55996 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387736AbgBMP2g (ORCPT ); Thu, 13 Feb 2020 10:28:36 -0500 Received: from localhost (unknown [104.132.1.104]) (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 9A48A2168B; Thu, 13 Feb 2020 15:28:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581607715; bh=AzMvOGFeP02uYb2htvlWBAJwij+2RSgKQh/WezhmmP4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aGWaCeEdmqZEqNI3wxhEBzcnLCxokNLOjN4QSdGFDDYdO3BOhHQfWBnN7HOybWPs6 GpeQQdPh23GGAkm85y3U9Ns9vufFPVcFTr7UHS+Tw7YSEypLyhkEy+rRbqwsimxq2q kInCSG8OwRpTGBbbqMlMMH/dzRltWD0zqQXfauK0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jakub Sitnicki , Daniel Borkmann , John Fastabend Subject: [PATCH 5.5 038/120] bpf, sockhash: Synchronize_rcu before freeing map Date: Thu, 13 Feb 2020 07:20:34 -0800 Message-Id: <20200213151914.760603850@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200213151901.039700531@linuxfoundation.org> References: <20200213151901.039700531@linuxfoundation.org> User-Agent: quilt/0.66 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 From: Jakub Sitnicki commit 0b2dc83906cf1e694e48003eae5df8fa63f76fd9 upstream. We need to have a synchronize_rcu before free'ing the sockhash because any outstanding psock references will have a pointer to the map and when they use it, this could trigger a use after free. This is a sister fix for sockhash, following commit 2bb90e5cc90e ("bpf: sockmap, synchronize_rcu before free'ing map") which addressed sockmap, which comes from a manual audit. Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: Jakub Sitnicki Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20200206111652.694507-3-jakub@cloudflare.com Signed-off-by: Greg Kroah-Hartman --- net/core/sock_map.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -250,6 +250,7 @@ static void sock_map_free(struct bpf_map } raw_spin_unlock_bh(&stab->lock); + /* wait for psock readers accessing its map link */ synchronize_rcu(); bpf_map_area_free(stab->sks); @@ -873,6 +874,9 @@ static void sock_hash_free(struct bpf_ma raw_spin_unlock_bh(&bucket->lock); } + /* wait for psock readers accessing its map link */ + synchronize_rcu(); + bpf_map_area_free(htab->buckets); kfree(htab); }