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Date:   Mon, 18 Jan 2021 00:01:52 +0000
From:   Al Viro <viro@zeniv.linux.org.uk>
To:     Steve French <smfrench@gmail.com>
Cc:     =?iso-8859-1?Q?Aur=E9lien?= Aptel <aaptel@suse.com>,
        Jiapeng Zhong <abaci-bugfix@linux.alibaba.com>,
        Steve French <sfrench@samba.org>,
        CIFS <linux-cifs@vger.kernel.org>,
        samba-technical <samba-technical@lists.samba.org>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] fs/cifs: Replace one-element array with flexible-array
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On Sun, Jan 17, 2021 at 03:58:23PM -0600, Steve French wrote:
> Jiapeng,
> Aurelien is correct, you should respin this patch and correct for
> where it breaks the sizeof calculation.  For example your change:
> 
> struct smb2_lock_rsp {
> @@ -1434,7 +1434,7 @@ struct smb2_query_directory_req {
>         __le16 FileNameOffset;
>         __le16 FileNameLength;
>         __le32 OutputBufferLength;
> -       __u8   Buffer[1];
> +       __u8   Buffer[];
>  } __packed;
> 
> would have the side effect of making the file name off by one:
> 
> smb2pdu.c-4654- req->FileNameOffset =
> smb2pdu.c:4655:         cpu_to_le16(sizeof(struct
> smb2_query_directory_req) - 1);

FWIW, that sizeof() - 1 should've been offsetof()...