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 7D434C433EF for ; Tue, 17 May 2022 09:12:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244327AbiEQJMw (ORCPT ); Tue, 17 May 2022 05:12:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45346 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243768AbiEQJMq (ORCPT ); Tue, 17 May 2022 05:12:46 -0400 Received: from mail-ed1-x52c.google.com (mail-ed1-x52c.google.com [IPv6:2a00:1450:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3D7C53055B; Tue, 17 May 2022 02:12:45 -0700 (PDT) Received: by mail-ed1-x52c.google.com with SMTP id j28so7495513eda.13; Tue, 17 May 2022 02:12:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=WSRw1Pwnan2nbIFjF7GvgpMAawLqzQo4p+q82BQEguE=; b=LjeX+DA75x1FUBh9TKF2FwzUAn42vtQcynsZgE53sBbfQ2Z+W/Q8EvBRkxSWSkFt9E ZzHkJEbd1yEw/kW3653DnDdqxVbzqoicSH2Ca9v1EM0KexEts3z0si04eArE33PAmQpm YP9iwaPxnodFuDxT0dbcx8QI/Im96YAg0MC0MNyxfNETOxiW7TR1aiMEcOI8vLT0RA+t VIwIutJ8k26XKrmHSyo2vCFlj24rx1HY0El/xVrV3VLK1yTBnmKacaH9blICJId9bO61 SMEAIbReF94tx5qKwYA6KNGH22wapcjP8Jq6Bao8y7TjUuYj3HgZpUoH+hhsSlAhDsjg HGWw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=WSRw1Pwnan2nbIFjF7GvgpMAawLqzQo4p+q82BQEguE=; b=OSNFgBH7BQNiZGPFdkKRh6CbNJoJMeI7ExRhNJCZS7arkWT7fSwPGJO8gkpuZEjOXp DAmNkVvj+pCNhL/stVCdQzVNPIo6OanqmQMsKcj41iu0E/gy8pL7Ixd8OE61z25geHBb mPTNdM4/d/IfIkYJ60/dDbk6mMbtjWtOP75o5XsacjSTydep5chYtZN8kTzfxvrCQqB0 mT3k2wknQomTOa+VwA4PH9YbalptZbN6DMYWnCHopItRh+WDKMf1Xk/4RNBEKR64Xymo dROseObpLRUPtwfhAp/MU4YE6eP1kYbj+VMxxsyv0APt0Jt+DmzjsqzOfJ3Vcc7nxIkZ DtWg== X-Gm-Message-State: AOAM532iBpson5lGpYNCQIwk3E7rQauyyt5ZInYMyZLn8bY12GLkDwGT dTT8HSly8RQuYubaPvCauvI= X-Google-Smtp-Source: ABdhPJzI+2mseapOLyonVdtI88hGRVWahwfpEgpTCab/cMq7qfEYOPFG16q4lbZAKku81lBLCRGMuA== X-Received: by 2002:a05:6402:3585:b0:427:ccd4:bec3 with SMTP id y5-20020a056402358500b00427ccd4bec3mr18004810edc.2.1652778763846; Tue, 17 May 2022 02:12:43 -0700 (PDT) Received: from krava ([193.85.244.190]) by smtp.gmail.com with ESMTPSA id s2-20020aa7cb02000000b0042617ba63a5sm6440784edt.47.2022.05.17.02.12.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 May 2022 02:12:43 -0700 (PDT) From: Jiri Olsa X-Google-Original-From: Jiri Olsa Date: Tue, 17 May 2022 11:12:41 +0200 To: Eugene Syromiatnikov Cc: Masami Hiramatsu , Steven Rostedt , Ingo Molnar , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, Shuah Khan , linux-kselftest@vger.kernel.org Subject: Re: [PATCH bpf-next v3 1/4] bpf_trace: check size for overflow in bpf_kprobe_multi_link_attach Message-ID: References: <9e4171972a3d75e656073e0c25cd4071a6f652e4.1652772731.git.esyr@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9e4171972a3d75e656073e0c25cd4071a6f652e4.1652772731.git.esyr@redhat.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, May 17, 2022 at 09:36:15AM +0200, Eugene Syromiatnikov wrote: > Check that size would not overflow before calculation (and return > -EOVERFLOW if it will), to prevent potential out-of-bounds write > with the following copy_from_user. Use kvmalloc_array > in copy_user_syms to prevent out-of-bounds write into syms > (and especially buf) as well. > > Fixes: 0dcac272540613d4 ("bpf: Add multi kprobe link") > Cc: # 5.18 > Signed-off-by: Eugene Syromiatnikov Acked-by: Jiri Olsa thanks, jirka > --- > kernel/trace/bpf_trace.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c > index 7141ca8..9c041be 100644 > --- a/kernel/trace/bpf_trace.c > +++ b/kernel/trace/bpf_trace.c > @@ -2261,11 +2261,11 @@ static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 > int err = -ENOMEM; > unsigned int i; > > - syms = kvmalloc(cnt * sizeof(*syms), GFP_KERNEL); > + syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); > if (!syms) > goto error; > > - buf = kvmalloc(cnt * KSYM_NAME_LEN, GFP_KERNEL); > + buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); > if (!buf) > goto error; > > @@ -2461,7 +2461,8 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr > if (!cnt) > return -EINVAL; > > - size = cnt * sizeof(*addrs); > + if (check_mul_overflow(cnt, (u32)sizeof(*addrs), &size)) > + return -EOVERFLOW; > addrs = kvmalloc(size, GFP_KERNEL); > if (!addrs) > return -ENOMEM; > -- > 2.1.4 >