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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90237C433F5 for ; Sat, 9 Oct 2021 08:46:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6E24960F70 for ; Sat, 9 Oct 2021 08:46:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231537AbhJIIs1 (ORCPT ); Sat, 9 Oct 2021 04:48:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39542 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230498AbhJIIs0 (ORCPT ); Sat, 9 Oct 2021 04:48:26 -0400 Received: from mail-lf1-x12e.google.com (mail-lf1-x12e.google.com [IPv6:2a00:1450:4864:20::12e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B8EFAC061570; Sat, 9 Oct 2021 01:46:29 -0700 (PDT) Received: by mail-lf1-x12e.google.com with SMTP id t9so47919527lfd.1; Sat, 09 Oct 2021 01:46:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=PQFex+l6mJ2QM53cZRA8HH/CoNAzt5qU9JaEKGvExmQ=; b=moYkKOSpR9qN+SuM1iPN1Z54f86fPY+fu70JLUTtwZE+0otm1zYLcqer4hd7C1wGfB OVW1KHz73QHkuNjwDLdZk4awVlF0XrlRhNHFylbuN+W21yicJDQa0MSNbfAdxvOVp++r 9TR3Z060tpb6FK7o3ryzL3zp8RJ0kP3p4TtH+k554f/b94FVJm/684eHJHQA+HRjNvMD RngSGqaN5spZy+gcgOYpGHKmHGgd5Rnz2sA5/doauHEEndi8ixjf0NgRuS3gNTLtCml4 jn++uYsLP+6+Vu2tvgQfndfLmf44DxWKekg6RsFd0CxQXw0inEDC7GqTKjuJooJiMWYr aXsw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=PQFex+l6mJ2QM53cZRA8HH/CoNAzt5qU9JaEKGvExmQ=; b=fRZHiAwg7lNpzsevUrgy6eFY1FvXKWihO8Erg1D8z2xsIJ/DT/iNdOLVRcOZARbR36 7B3ftxJRYAqOtyfK0bfc7z4TnjbW0g1le0qF3rW90PyMEMFWMTU1/hSylL8wT3vR8aHQ 7kFWY4uP9S6EyI/GWqAEMtUoE5/GYSL6aYeOK0ZY+Rv2Qj1ZGYP49cmYDZEb6WElhyP3 DTGZld7jkLEff+h8/lEKuZpDNbovPFR8VyvPCPFrA310wzbmSz/LXZZjf7mBKfTAEU5+ GSS4l9BWKIl0duq/LYKxJtiBeEeRtrrZakH8QXdgwX4G5ArM8wvmFsC5UOV5ly8tG/Du SrGg== X-Gm-Message-State: AOAM5302WaNzAceX8yfZ98FNe2z+KKrrqO1w4gdaYg48qL7P3idosHSn yXFX6blg7Tzoc/tovwqwsck= X-Google-Smtp-Source: ABdhPJw2GB9YllD74fx6MhU3AijPxn1PR9GBk4Wkod3ySgjMBLW8mYDiC+9/Af5NNZ3OGL1sLtuMYw== X-Received: by 2002:a2e:7504:: with SMTP id q4mr9074100ljc.422.1633769188020; Sat, 09 Oct 2021 01:46:28 -0700 (PDT) Received: from [192.168.1.11] ([94.103.235.120]) by smtp.gmail.com with ESMTPSA id w11sm153795lfn.93.2021.10.09.01.46.27 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 09 Oct 2021 01:46:27 -0700 (PDT) Message-ID: Date: Sat, 9 Oct 2021 11:46:23 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.1.1 Subject: Re: [PATCH] block: nbd: fix sanity check for first_minor Content-Language: en-US To: "Yan, Zheng" , axboe@kernel.dk, Christoph Hellwig Cc: "Yan, Zheng" , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org References: <20211009053540.95100-1-ukernel@gmail.com> From: Pavel Skripkin In-Reply-To: <20211009053540.95100-1-ukernel@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/9/21 08:35, Yan, Zheng wrote: +CC Christoph > From: "Yan, Zheng" > > Device's minor is a 20-bits number, max value is 0xfffff. > > Fixes: b1a811633f ("block: nbd: add sanity check for first_minor"). > Signed-off-by: "Yan, Zheng" > --- > drivers/block/nbd.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c > index 1183f7872b71..53cd038c96e9 100644 > --- a/drivers/block/nbd.c > +++ b/drivers/block/nbd.c > @@ -1753,7 +1753,7 @@ static struct nbd_device *nbd_dev_add(int index, unsigned int refs) > * byte in __device_add_disk(). > */ > disk->first_minor = index << part_shift; > - if (disk->first_minor > 0xff) { > + if (disk->first_minor > MINORMASK) { > err = -EINVAL; > goto out_free_idr; > } > I've looked into what confused me with 0xff and I found that uapi's kdev_t.h has following MINOR definition: #define MINOR(dev) ((dev) & 0xff) But kernel's kdev_t.h is really allows 20 bit minor number :) Also, can you, please, fix up comment above this check, since it contains info about max minor 0xff and it can confuse readers. With regards, Pavel Skripkin