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=-6.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 E141DC433E0 for ; Tue, 26 May 2020 21:10:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4D53208C3 for ; Tue, 26 May 2020 21:10:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="taOgEz1p" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389966AbgEZVKl (ORCPT ); Tue, 26 May 2020 17:10:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52960 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388900AbgEZVKk (ORCPT ); Tue, 26 May 2020 17:10:40 -0400 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3800AC061A0F; Tue, 26 May 2020 14:10:40 -0700 (PDT) Received: by mail-pg1-x541.google.com with SMTP id d10so10673955pgn.4; Tue, 26 May 2020 14:10:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :content-transfer-encoding; bh=LQ07X5bAq3Ki1aAX/noIXrCEkby3LJZQPnhWb4E5GUk=; b=taOgEz1ppNiAxsHsY6RuY8GtvxE7Y9WvNL2ppqBmENgFbZ50Ksgx+OxpFVV3pkUlpR xi0EMl2ZmZh/A6ljW3Zf0HH/b6R616adjjS0Lo+sDjCpOuOxM13FLrT/WUFaU7YshhrS J1d8I2ZEnJM4QsSLf8lOL+9T3xBCQTq7KO/XYZf3JrcOv6CMxmlpiMucq9njwlk9QDLp 8aT0qOXeNoR6sR85qy41kA73rousDRBn905VrKiAgYdscrqHBqB1ycyA4zIIV/2eefxC G5CbZX15eQr7G3mCPdSDNXjEaP05ArMzqazPPprvfrkmioJvFp9lPNhjcsH569dwlxXX Ccfg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:message-id:in-reply-to:references :subject:mime-version:content-transfer-encoding; bh=LQ07X5bAq3Ki1aAX/noIXrCEkby3LJZQPnhWb4E5GUk=; b=XEhguT5E1fRA6zctGhMQ9COmvqrAnGLH9VVXrkxPlhLeWWrJdhlYC8/1KUuX+iSUlO lcoMZuShAw2/JUUt8MiCpLgqHxXsN0v7KxrSCGyt9OOZ9Ot8iwHto3ci6Tx8cHINceZE QelJD0+rLnKn4I8FcSumrVArDyfoiSZ+nwh5zyBaqlx3ZrCCPKnaVtaNXjZkz4LgDyLZ NBggYnQrVUOA82BvYkm617Oy37yO8ppVcSzsnCljITq5EFAtIh35DI/PSX8kJidb7YAv 3Ku9oWJz7itRp9JJlybFpbR5pqXboAvjRzjlhw+KSvn1OTb3gUzFy+vvZhsVbjvZJlqg ST1Q== X-Gm-Message-State: AOAM532PKzouv43FfhFcw3rKuzJktGxfgj3nvGHUWwmrG9G5voriETWm LG//QMnvYoMBOsuoAxzz0V4= X-Google-Smtp-Source: ABdhPJwYI63FtqISWI/Jl563YFOg5YPghRJbQn8RnadTZE/Fm4gWxXreTsGZZgrl8dKuvEQ6M3JvVg== X-Received: by 2002:a65:498f:: with SMTP id r15mr716284pgs.345.1590527439802; Tue, 26 May 2020 14:10:39 -0700 (PDT) Received: from localhost ([184.63.162.180]) by smtp.gmail.com with ESMTPSA id h7sm446324pgn.60.2020.05.26.14.10.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 May 2020 14:10:38 -0700 (PDT) Date: Tue, 26 May 2020 14:10:31 -0700 From: John Fastabend To: dihu , Eric Dumazet , John Fastabend , Daniel Borkmann , Jakub Sitnicki , Lorenz Bauer , "David S. Miller" , Alexey Kuznetsov , Hideaki YOSHIFUJI , Jakub Kicinski , Alexei Starovoitov , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , KP Singh , netdev , bpf , linux-kernel Message-ID: <5ecd85c7a21fd_35792ad4115a05b8a9@john-XPS-13-9370.notmuch> In-Reply-To: References: Subject: RE: [PATCH] bpf/sockmap: fix kernel panic at __tcp_bpf_recvmsg Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org dihu wrote: > From 865a45747de6b68fd02a0ff128a69a5c8feb73c3 Mon Sep 17 00:00:00 2001 > From: dihu > Date: Mon, 25 May 2020 17:23:16 +0800 > Subject: [PATCH] bpf/sockmap: fix kernel panic at __tcp_bpf_recvmsg > > When user application calls read() with MSG_PEEK flag to read data > of bpf sockmap socket, kernel panic happens at > __tcp_bpf_recvmsg+0x12c/0x350. sk_msg is not removed from ingress_msg > queue after read out under MSG_PEEK flag is set. Because it's not > judged whether sk_msg is the last msg of ingress_msg queue, the next > sk_msg may be the head of ingress_msg queue, whose memory address of > sg page is invalid. So it's necessary to add check codes to prevent > this problem. > > [20759.125457] BUG: kernel NULL pointer dereference, address: > 0000000000000008 > [20759.132118] CPU: 53 PID: 51378 Comm: envoy Tainted: G E > 5.4.32 #1 > [20759.140890] Hardware name: Inspur SA5212M4/YZMB-00370-109, BIOS > 4.1.12 06/18/2017 > [20759.149734] RIP: 0010:copy_page_to_iter+0xad/0x300 > [20759.270877] __tcp_bpf_recvmsg+0x12c/0x350 > [20759.276099] tcp_bpf_recvmsg+0x113/0x370 > [20759.281137] inet_recvmsg+0x55/0xc0 > [20759.285734] __sys_recvfrom+0xc8/0x130 > [20759.290566] ? __audit_syscall_entry+0x103/0x130 > [20759.296227] ? syscall_trace_enter+0x1d2/0x2d0 > [20759.301700] ? __audit_syscall_exit+0x1e4/0x290 > [20759.307235] __x64_sys_recvfrom+0x24/0x30 > [20759.312226] do_syscall_64+0x55/0x1b0 > [20759.316852] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > Signed-off-by: dihu > --- > net/ipv4/tcp_bpf.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c > index 5a05327..c0d4624 100644 > --- a/net/ipv4/tcp_bpf.c > +++ b/net/ipv4/tcp_bpf.c > @@ -64,6 +64,9 @@ int __tcp_bpf_recvmsg(struct sock *sk, struct sk_psock *psock, > } while (i != msg_rx->sg.end); > > if (unlikely(peek)) { > + if (msg_rx == list_last_entry(&psock->ingress_msg, > + struct sk_msg, list)) > + break; Thanks. Change looks good but spacing is a bit off . Can we turn those spaces into tabs? Otherwise adding fixes tag and my ack would be great. Fixes: 02c558b2d5d67 ("bpf: sockmap, support for msg_peek in sk_msg with redirect ingress") Acked-by: John Fastabend