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	Thu, 03 Sep 2026 08:22:48 +0200
Date: Thu, 3 Sep 2026 08:22:48 +0200
From: Johan Hovold <johan@kernel.org>
To: Adriano Cordova <adrianox@gmail.com>
Cc: gregkh@linuxfoundation.org, jirislaby@kernel.org,
	linux-usb@vger.kernel.org, linux-serial@vger.kernel.org,
	syzbot+473d7477c523b41d4046@syzkaller.appspotmail.com
Subject: Re: [PATCH v2 0/2] tty: fix break race
Message-ID: <apkSOF1l7VYTpzul@hovoldconsulting.com>
References: <20260903042429.130320-1-adrianox@gmail.com>
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In-Reply-To: <20260903042429.130320-1-adrianox@gmail.com>

On Thu, Sep 03, 2026 at 12:24:27AM -0400, Adriano Cordova wrote:
> A timed break (TCSBRK/TCSBRKP) and the unconditional TIOCSBRK/TIOCCBRK
> can race against USB disconnect and call break_ctl() after the device is
> gone, dereferencing freed port data in keyspan_break_ctl().
> 
> Both patches are needed: the tty core must not issue break_ctl() to a
> hung-up tty, and serial_break() must not call the driver after
> disconnect. This is the same two-layer protection read and write already
> use.

This doesn't work and as I said in my reply to the syzbot report I'm
preparing a proper fix.

Johan