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Subject: Re: [PATCH net] net/packet: move reference count in packet_sock to 64
 bits
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, netdev@vger.kernel.org
Cc: "The UK's National Cyber Security Centre (NCSC)" <security@ncsc.gov.uk>,
 stable <stable@kernel.org>,
 Willem de Bruijn <willemdebruijn.kernel@gmail.com>
References: <2023113042-unfazed-dioxide-f854@gregkh>
From: Daniel Borkmann <daniel@iogearbox.net>
Message-ID: <37d84da7-12d2-7646-d4fb-240d1023fe7a@iogearbox.net>
Date: Thu, 30 Nov 2023 15:36:59 +0100
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On 11/30/23 3:20 PM, Greg Kroah-Hartman wrote:
> In some potential instances the reference count on struct packet_sock
> could be saturated and cause overflows which gets the kernel a bit
> confused.  To prevent this, move to a 64bit atomic reference count to
> prevent the possibility of this type of overflow.
> 
> Because we can not handle saturation, using refcount_t is not possible
> in this place.  Maybe someday in the future if it changes could it be
> used.
> 
> Original version from Daniel after I did it wrong, I've provided a
> changelog.
> 
> Reported-by: "The UK's National Cyber Security Centre (NCSC)" <security@ncsc.gov.uk>
> Cc: stable <stable@kernel.org>
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Thanks!

Acked-by: Daniel Borkmann <daniel@iogearbox.net>