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Date:   Thu, 30 Jun 2022 17:18:11 +0200
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Yangxi Xiang <xyangxi5@gmail.com>
Cc:     linux-kernel@vger.kernel.org, Jiri Slaby <jirislaby@kernel.org>,
        Johan Hovold <johan@kernel.org>,
        Igor Matheus Andrade Torrente <igormtorrente@gmail.com>,
        Christian Borntraeger <borntraeger@linux.ibm.com>,
        nick black <dankamongmen@gmail.com>
Subject: Re: [PATCH v3] vt: fix memory overlapping when deleting chars in the
 buffer
Message-ID: <Yr2+s6wQWSfq/Gl5@kroah.com>
References: <20220628093322.5688-1-xyangxi5@gmail.com>
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On Tue, Jun 28, 2022 at 05:33:22PM +0800, Yangxi Xiang wrote:
> A memory overlapping copy occurs when deleting a long line. This memory
> overlapping copy can cause data corruption when scr_memcpyw is optimized
> to memcpy because memcpy does not ensure its behavior if the destination
> buffer overlaps with the source buffer. The line buffer is not always
> broken, because the memcpy utilizes the hardware acceleration, whose
> result is not deterministic.
> 
> Fix this problem by using replacing the scr_memcpyw with scr_memmovew.
> 
> Fixes: 81732c3b2fed ("Fix line garbage in virtual console")

Nit, this should have been:
	Fixes: 81732c3b2fed ("tty vt: Fix line garbage in virtual console on command line edition")

otherwise our tools complain.  I've fixed it up when applying it.

thanks,

greg k-h