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Date: Thu, 9 Nov 2023 02:40:23 +0000
From: Al Viro <viro@zeniv.linux.org.uk>
To: WoZ1zh1 <wozizhi@huawei.com>
Cc: brauner@kernel.org, akpm@linux-foundation.org, oleg@redhat.com,
	jlayton@kernel.org, dchinner@redhat.com, cyphar@cyphar.com,
	shr@devkernel.io, linux-kernel@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, yangerkun@huawei.com
Subject: Re: [PATCH -next V2] proc: support file->f_pos checking in mem_lseek
Message-ID: <20231109024023.GZ1957730@ZenIV>
References: <20231109102658.2075547-1-wozizhi@huawei.com>
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Sender: Al Viro <viro@ftp.linux.org.uk>

On Thu, Nov 09, 2023 at 06:26:58PM +0800, WoZ1zh1 wrote:
> In mem_lseek, file->f_pos may overflow. And it's not a problem that
> mem_open set file mode with FMODE_UNSIGNED_OFFSET(memory_lseek). However,
> another file use mem_lseek do lseek can have not FMODE_UNSIGNED_OFFSET
> (kpageflags_proc_ops/proc_pagemap_operations...), so in order to prevent
> file->f_pos updated to an abnormal number, fix it by checking overflow and
> FMODE_UNSIGNED_OFFSET.

Umm...  Is there any reasons why all of those shouldn't get FMODE_UNSIGNED_OFFSET
as well?