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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 82DB7C433F5 for ; Wed, 18 May 2022 23:40:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229966AbiERXkW (ORCPT ); Wed, 18 May 2022 19:40:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231161AbiERXkQ (ORCPT ); Wed, 18 May 2022 19:40:16 -0400 Received: from mail-il1-x12f.google.com (mail-il1-x12f.google.com [IPv6:2607:f8b0:4864:20::12f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5EC8A19F9C; Wed, 18 May 2022 16:40:09 -0700 (PDT) Received: by mail-il1-x12f.google.com with SMTP id j4so2568924ilo.12; Wed, 18 May 2022 16:40:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ds55Bsv2GoSLlas6Dx1JEfsoZ0HMGPTIqjaaEFNjM4s=; b=MVMSLxVIfMq48TSV7NuTXRJi2JtJzM91wrtDADX9u2HqOcsQUMjXvUm4zvK4CPu36c wDxujsuklyIUW0r6/LEpbQB7hK7CUJpIk/ovM3JmNfqK3wJ8QnegsLalRNx1N5FGhYTP KG7GsiZnAJ4FASfvM/GjdpMZ1/lSweyRDeLkTzdgFQ9aqo5rdTOlPkgzh8445SQQ0469 BI64pssj+QQE53NHn/jMCxOrrc8VjOJ8kNJ7yBReJvmrra9H3kYcF20VWUwgUrnzHltL yAlbgsBuJs8PkGP+MeL3bod+O/uFHTaksgZC0z6rEFF3upqPDWv4IVmoYbWm5C5NhB9h odPQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=ds55Bsv2GoSLlas6Dx1JEfsoZ0HMGPTIqjaaEFNjM4s=; b=DPCXA1O3OJ6jhDGw/HbDuPchBAwqPHbiMCk5xvt0YwiZGzhlDUGMioGal3dWsLEOvS +U7ZCfrH/+vo8vOL4F4jbwRMhqSNMhX6PE+pr3LCDR4r6fhjVAHksqnz3rmuVTtXIRJz Dp3XXITXr/AmY2IgnMj2xSQ3B0ZZGHzzXrt3ZrJ4mON07MgpgEEDMWTQwc0Gg65OYsHC 7YknHJeYbDyWGEos3S0bUVDVauv8M9wesIKHjzLcy56puxcepWZQN8F2E+cSfEzV9flU pTyT3uh4qm1npz9wbguy5DFc0vAOtsJUln0j03jZoV69NyI0TP2goT8IIPO488iJjakg RN+Q== X-Gm-Message-State: AOAM531QDmqUKgSsw1SoC1lKtnqpfbrZv3cpdmM3NWhk1+XcUdoAmP8K uAw/uvL4wfwvhHG0X9lsF04SDkyrQ4ERsQC1nqrfxurq X-Google-Smtp-Source: ABdhPJx71PNkY/+fugXu0eLFpyXyRIK3eZEfdpKQ/KC0+btRbofLGvd6mL81LdgeIgjGNpQxGpU+oyIwAPfF1yq1fH4= X-Received: by 2002:a05:6e02:1c01:b0:2d1:262e:8d5f with SMTP id l1-20020a056e021c0100b002d1262e8d5fmr1115383ilh.98.1652917208798; Wed, 18 May 2022 16:40:08 -0700 (PDT) MIME-Version: 1.0 References: <2a56d66cf4b9430982e81233f49d6c54988df056.1652772731.git.esyr@redhat.com> In-Reply-To: <2a56d66cf4b9430982e81233f49d6c54988df056.1652772731.git.esyr@redhat.com> From: Andrii Nakryiko Date: Wed, 18 May 2022 16:39:58 -0700 Message-ID: Subject: Re: [PATCH bpf-next v3 3/4] bpf_trace: handle compat in copy_user_syms To: Eugene Syromiatnikov Cc: Jiri Olsa , Masami Hiramatsu , Steven Rostedt , Ingo Molnar , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Networking , bpf , open list , Shuah Khan , "open list:KERNEL SELFTEST FRAMEWORK" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 17, 2022 at 12:36 AM Eugene Syromiatnikov wrote: > > For compat processes, userspace size for syms pointers is different. > Provide compat handling for copying array elements from the user space. > > Fixes: 0dcac272540613d4 ("bpf: Add multi kprobe link") > Signed-off-by: Eugene Syromiatnikov > --- > kernel/trace/bpf_trace.c | 20 +++++++++++++++++++- > 1 file changed, 19 insertions(+), 1 deletion(-) > > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c > index a93a54f..9d3028a 100644 > --- a/kernel/trace/bpf_trace.c > +++ b/kernel/trace/bpf_trace.c > @@ -2253,6 +2253,24 @@ struct user_syms { > char *buf; > }; > > +static inline int get_arr_ptr(unsigned long *p, > + unsigned long __user *uaddr, u32 idx) no need for inline, let compiler decide on inlining > +{ > + if (unlikely(in_compat_syscall())) { not sure unlikely() is justified for code... > + compat_uptr_t __user *compat_uaddr = (compat_uptr_t __user *)uaddr; > + compat_uptr_t val; > + int err; > + > + err = __get_user(val, compat_uaddr + idx); > + if (!err) > + *p = val; > + > + return err; > + } else { > + return __get_user(*p, uaddr + idx); > + } > +} > + > static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) > { > unsigned long __user usymbol; > @@ -2270,7 +2288,7 @@ static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 > goto error; > > for (p = buf, i = 0; i < cnt; i++) { > - if (__get_user(usymbol, usyms + i)) { > + if (get_arr_ptr(&usymbol, usyms, i)) { > err = -EFAULT; > goto error; > } > -- > 2.1.4 >