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Date: Tue, 23 Jan 2024 13:32:35 -0800
From: Kees Cook <keescook@chromium.org>
To: Jan Beulich <jbeulich@suse.com>
Cc: Wei Liu <wei.liu@kernel.org>, Paul Durrant <paul@xen.org>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	xen-devel@lists.xenproject.org, netdev@vger.kernel.org,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	Bill Wendling <morbo@google.com>,
	Justin Stitt <justinstitt@google.com>, linux-kernel@vger.kernel.org,
	linux-hardening@vger.kernel.org
Subject: Re: [PATCH 80/82] xen-netback: Refactor intentional wrap-around test
Message-ID: <202401231331.0BD2925D4E@keescook>
References: <20240122235208.work.748-kees@kernel.org>
 <20240123002814.1396804-80-keescook@chromium.org>
 <35ff4947-7863-40da-b0e7-3b84e17c6163@suse.com>
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In-Reply-To: <35ff4947-7863-40da-b0e7-3b84e17c6163@suse.com>

On Tue, Jan 23, 2024 at 08:55:44AM +0100, Jan Beulich wrote:
> On 23.01.2024 01:27, Kees Cook wrote:
> > --- a/drivers/net/xen-netback/hash.c
> > +++ b/drivers/net/xen-netback/hash.c
> > @@ -345,7 +345,7 @@ u32 xenvif_set_hash_mapping(struct xenvif *vif, u32 gref, u32 len,
> >  		.flags = GNTCOPY_source_gref
> >  	}};
> >  
> > -	if ((off + len < off) || (off + len > vif->hash.size) ||
> > +	if ((add_would_overflow(off, len)) || (off + len > vif->hash.size) ||
> 
> I'm not maintainer of this code, but if I was I would ask that the
> excess parentheses be removed, to improve readability.

Good call. I will adjust that. Thanks!

-Kees

-- 
Kees Cook