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Subject: Re: jsm_tty: Fix a possible null pointer dereference in two functions
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-serial@vger.kernel.org
Cc: Joe Perches <joe@perches.com>,
        "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com>,
        Jiri Slaby <jslaby@suse.com>, LKML <linux-kernel@vger.kernel.org>,
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 <1511977896.19952.69.camel@perches.com> <20171129180528.GA24705@kroah.com>
From: SF Markus Elfring <elfring@users.sourceforge.net>
Message-ID: <089a4b85-64e8-cb4a-c5f8-9abb2556e5e5@users.sourceforge.net>
Date: Wed, 29 Nov 2017 19:19:05 +0100
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>> It's pretty unlikely, but it is an actual defect.
> 
> No it is not, those variables will never be set to NULL,
> so this can never be triggered.  Walk up the call chain.

If the involved software developers are convinced about the validity
of this pointer:

How do you think about to delete the following condition check
instead in the discussed function implementations?

	if (!ch)
		return;


Regards,
Markus