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 0F929ECAAA1 for ; Fri, 9 Sep 2022 17:27:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230183AbiIIR1b (ORCPT ); Fri, 9 Sep 2022 13:27:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59306 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229517AbiIIR12 (ORCPT ); Fri, 9 Sep 2022 13:27:28 -0400 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3933337F9E for ; Fri, 9 Sep 2022 10:27:28 -0700 (PDT) Received: by mail-pf1-x449.google.com with SMTP id ay1-20020a056a00300100b0053e7e97696bso1392253pfb.3 for ; Fri, 09 Sep 2022 10:27:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date; bh=4U0Cv792MiLLT3xqs4tLXzlENCdHaXq6QFZB5ccoybY=; b=sk4rX+o2kF0PpS+GapykbME7V/iKflBOVs5DX+no6UBgfZ0GCN+R1gzNqcy20y9TY6 lk6gQA9BXhHQZZL+/+gtkgVU3TFNsJDcOykvHYigFcUOWqN3vbirbeZ1fUqT9TEuWzAq TXNCfaLVHN8jt6rqMwOMc3685zlnJkAT00C0eO6sfKHl4X30DJ8AdNs4fIF1kRsLp4Jp joiA7TjSYfdVOCMpAm2vQo1REHjVoVpaqACOBUiFeiqyCw/jgQAU0/22xJj95dpDgR52 wGa9xhd84e3+8uooFqK2fMNGnpO/YcMtS3qVMjByFzfE2COMYHUwNldDVAkPXwpq8HZW 151Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date; bh=4U0Cv792MiLLT3xqs4tLXzlENCdHaXq6QFZB5ccoybY=; b=3Nh8j2Py3lIRNAvZAxP6+3sMovsCVu4Yh31vnrMP7TdQHmLGfILHRfCEPEfGozTXkC Hgw/pvWv4WtDCQEyvNgAT2mAe4p3/hf8eYZpOQ8h0PBsjwRRl6/SHBzdJJmC8D05caEj RpHYBdPSsRh+FUybYnLM8dRYnywIqesECXr2h+5hNfjQca+OS+5PGmjaXwNT634R1rtu HlHmTKt/vl4ZQJuCQgRWQiPBhW1OdHYXGOTzFBpSH5mFrWe6l4Sdz/fbQ2HP4UPKnjj2 HaDOtcrCF6yn8XYomgDK/OOayhhLL7wp2PKiaKbL2e8BBOacqAhuoRCQtNQev+F1aJ1/ ZjWg== X-Gm-Message-State: ACgBeo1iODxVjDAz0WvYh2tj+4c4JgkRWT+iIbGyrtY3shrKF1wngH+h kfXmZ6Rm46osh3DjRu+aIBbo1B0= X-Google-Smtp-Source: AA6agR4/1v8k4P0tIGrMaKelSGXTF4hBGJOJrswI6GLsXRjbKUupDQjGRlD+EMWMrHFnGqLJszd59GI= X-Received: from sdf.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5935]) (user=sdf job=sendgmr) by 2002:a17:90b:4b11:b0:202:998b:71b1 with SMTP id lx17-20020a17090b4b1100b00202998b71b1mr1706703pjb.208.1662744447776; Fri, 09 Sep 2022 10:27:27 -0700 (PDT) Date: Fri, 9 Sep 2022 10:27:26 -0700 In-Reply-To: <1662721097-23793-1-git-send-email-wangyufen@huawei.com> Mime-Version: 1.0 References: <1662721097-23793-1-git-send-email-wangyufen@huawei.com> Message-ID: Subject: Re: [bpf-next] bpf: use kvmemdup_bpfptr helper From: sdf@google.com To: Wang Yufen Cc: ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, kpsingh@kernel.org, haoluo@google.com, jolsa@kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/09, Wang Yufen wrote: > Use kvmemdup_bpfptr helper instead of open-coding to > simplify the code. > Signed-off-by: Wang Yufen > --- > kernel/bpf/syscall.c | 14 ++++---------- > 1 file changed, 4 insertions(+), 10 deletions(-) > diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c > index 4e9d4622aef7..13ce28081982 100644 > --- a/kernel/bpf/syscall.c > +++ b/kernel/bpf/syscall.c > @@ -1413,20 +1413,14 @@ static int map_update_elem(union bpf_attr *attr, > bpfptr_t uattr) > } > value_size = bpf_map_value_size(map); > - > - err = -ENOMEM; > - value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); > - if (!value) > + value = kvmemdup_bpfptr(uvalue, value_size); > + if (IS_ERR(value)) { > + err = PTR_ERR(value); > goto free_key; > - > - err = -EFAULT; > - if (copy_from_bpfptr(value, uvalue, value_size) != 0) > - goto free_value; > + } > err = bpf_map_update_value(map, f, key, value, attr->flags); [..] > -free_value: > - kvfree(value); And here you leak the value. We need to free it after update regardless of error/success. That's why it is coded like that. > free_key: > kvfree(key); > err_put: > -- > 2.25.1