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Date:   Wed, 25 Oct 2023 23:20:23 +0200
From:   Sabrina Dubroca <sd@queasysnail.net>
To:     Jakub Kicinski <kuba@kernel.org>
Cc:     Hangyu Hua <hbh25y@gmail.com>, borisp@nvidia.com,
        john.fastabend@gmail.com, davem@davemloft.net, edumazet@google.com,
        pabeni@redhat.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: tls: Fix possible NULL-pointer dereference in
 tls_decrypt_device() and tls_decrypt_sw()
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2023-10-25, 07:14:08 -0700, Jakub Kicinski wrote:
> On Wed, 25 Oct 2023 12:27:05 +0200 Sabrina Dubroca wrote:
> > > My bad. I only checked &msg->msg_iter's address in tls_decrypt_sw and found
> > > it was wrong. Do I need to make a new patch to fix the harmless bogus
> > > pointer?  
> > 
> > I don't think that's necessary, but maybe it would avoid people trying
> > to "fix" this code in the future. Jakub, WDYT?
> 
> No strong feelings, but personally I find checks for conditions which
> cannot happen decrease the readability. Maybe a comment is better?

There's already a comment above tls_decrypt_sg that (pretty much) says
out_iov is only used in zero-copy mode.

 *          [...]            The input parameter 'darg->zc' indicates if
 * zero-copy mode needs to be tried or not. With zero-copy mode, either
 * out_iov or out_sg must be non-NULL.

Do we need another just above the call to tls_decrypt_sg?

-- 
Sabrina