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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 072BBC3B19F for ; Fri, 14 Feb 2020 16:04:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CAB8224676 for ; Fri, 14 Feb 2020 16:04:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581696297; bh=JrHjtwzZrIE4QpB3v0AizW6puXMwCqlkDOToOFzYGYM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Ouly+G51JWmASGNLtgcffCf39J8f9+2QdLV3RLZiBDg+aHXQf5ehcNx60Xa6n3+F/ oeHFSWhMd6QaK8hynS2Cikdf8eiKsy0XSwF3gb/zANZGUzkXyPHEOsYJoIWpB0fjts GQelqUxJDYwmKa/r+V56MMduruj3tAc1fqIG4k/g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390036AbgBNQE4 (ORCPT ); Fri, 14 Feb 2020 11:04:56 -0500 Received: from mail.kernel.org ([198.145.29.99]:52396 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389923AbgBNQEX (ORCPT ); Fri, 14 Feb 2020 11:04:23 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6AF6A24676; Fri, 14 Feb 2020 16:04:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581696262; bh=JrHjtwzZrIE4QpB3v0AizW6puXMwCqlkDOToOFzYGYM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NyY04pnYxXWAK8ru0vk3cIZqUYNjSiJwr8ilJWYr4Dm7+daiLfQqWxxVJP2DPmLBh ASGD+YkelSWoyyYOOjmifw5lTEbuve+B83GX9Uv4tQMBYJWNWwHEDEmBnOenVC7nw/ ThPbA3F7b8SNt+xNCDQV3RqBd4JoE0uzIOjR9nm8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jakub Sitnicki , Daniel Borkmann , John Fastabend , Sasha Levin , netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 115/459] bpf, sockhash: Synchronize_rcu before free'ing map Date: Fri, 14 Feb 2020 10:56:05 -0500 Message-Id: <20200214160149.11681-115-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200214160149.11681-1-sashal@kernel.org> References: <20200214160149.11681-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 [ Upstream commit 0b2dc83906cf1e694e48003eae5df8fa63f76fd9 ] 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: Sasha Levin --- net/core/sock_map.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/core/sock_map.c b/net/core/sock_map.c index 8998e356f4232..058422b932607 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -250,6 +250,7 @@ static void sock_map_free(struct bpf_map *map) raw_spin_unlock_bh(&stab->lock); rcu_read_unlock(); + /* 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_map *map) } rcu_read_unlock(); + /* wait for psock readers accessing its map link */ + synchronize_rcu(); + bpf_map_area_free(htab->buckets); kfree(htab); } -- 2.20.1