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=-8.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 1152ECA9EC3 for ; Thu, 31 Oct 2019 10:22:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D8C8B2087F for ; Thu, 31 Oct 2019 10:22:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="HQRmrPHi" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726864AbfJaKWk (ORCPT ); Thu, 31 Oct 2019 06:22:40 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:55240 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727338AbfJaKWj (ORCPT ); Thu, 31 Oct 2019 06:22:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1572517358; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2k3svT9De3L0lWfpdoQdAnva/hB6fqGWLxfhXOerFXU=; b=HQRmrPHilJCK7AfovC/QgKJYaKnJMerniIm4zzTDxrHN6OpaagY1DfL7KZ+6+aQAekBmmM qIrMphjBS0vRI7ea5HljL9Kjj/SqdLqTcQ331BuLO9YaqjygSb8ct9RA3VBEIigaLuE45m TAg8H3zicRdVFLhAZfTkmVVc3EQQdko= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-324-5VX4BvhyN1SeqyjhNAg0ow-1; Thu, 31 Oct 2019 06:22:33 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 78E791800D56; Thu, 31 Oct 2019 10:22:32 +0000 (UTC) Received: from krava (unknown [10.40.205.171]) by smtp.corp.redhat.com (Postfix) with SMTP id 7CAFC5E24A; Thu, 31 Oct 2019 10:22:30 +0000 (UTC) Date: Thu, 31 Oct 2019 11:22:29 +0100 From: Jiri Olsa To: Alexei Starovoitov Cc: davem@davemloft.net, daniel@iogearbox.net, netdev@vger.kernel.org, bpf@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH bpf-next] bpf: Fix bpf jit kallsym access Message-ID: <20191031102229.GA2794@krava> References: <20191030233019.1187404-1-ast@kernel.org> MIME-Version: 1.0 In-Reply-To: <20191030233019.1187404-1-ast@kernel.org> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-MC-Unique: 5VX4BvhyN1SeqyjhNAg0ow-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Oct 30, 2019 at 04:30:19PM -0700, Alexei Starovoitov wrote: > Jiri reported crash when JIT is on, but net.core.bpf_jit_kallsyms is off. > bpf_prog_kallsyms_find() was skipping addr->bpf_prog resolution > logic in oops and stack traces. That's incorrect. > It should only skip addr->name resolution for 'cat /proc/kallsyms'. > That's what bpf_jit_kallsyms and bpf_jit_harden protect. >=20 > Reported-by: Jiri Olsa > Signed-off-by: Alexei Starovoitov > Fixes: 3dec541b2e63 ("bpf: Add support for BTF pointers to x86 JIT") it fixes the crash for me, thanks for quick fix jirka > --- > kernel/bpf/core.c | 3 --- > 1 file changed, 3 deletions(-) >=20 > diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c > index 673f5d40a93e..8d3fbc86ca5e 100644 > --- a/kernel/bpf/core.c > +++ b/kernel/bpf/core.c > @@ -668,9 +668,6 @@ static struct bpf_prog *bpf_prog_kallsyms_find(unsign= ed long addr) > { > =09struct latch_tree_node *n; > =20 > -=09if (!bpf_jit_kallsyms_enabled()) > -=09=09return NULL; > - > =09n =3D latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops); > =09return n ? > =09 container_of(n, struct bpf_prog_aux, ksym_tnode)->prog : > --=20 > 2.17.1 >=20