From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f198.google.com (mail-oi1-f198.google.com [209.85.167.198]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1B2DF250BF2 for ; Fri, 28 Aug 2026 01:28:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.198 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787880532; cv=none; b=Q0bhldNzwea5B58QssZmsc5aE2EfYi5HASBiN7mL7vj0aSrpEAYRWCP9CyOlLzN+16q6y3fqupAGkE8Iv+ZgElD3htm3H5SA7Ug+DJTWNHWVrWkMkG6RJsn4VXFBiCfQbbFUgMvOB2ZXqPtv1ZOM6MqvZElZWcCvFkwXzVWBJl4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787880532; c=relaxed/simple; bh=BYHFmCFPWmb5ot5TgEjuSBCPTrnPvfmVEuBXLl/h42M=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=hdaUXATyQ+eg2jbcYeRru7QIZ3PPLIzo0Jz9lLKaSRTwDrGLufSqkUB9AZ5EzQ3gytqPUlATQrU0NIUGp01p/4t28d8fVzPPHKkg6cDF2n0mX9CIfO3lDqJFGiIkxDRW25QBsuZn4I65PAowMpYvQ62sGL8LnCzpw3xs0NhUPUw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.167.198 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oi1-f198.google.com with SMTP id 5614622812f47-4ab8b4887d4so326923b6e.1 for ; Thu, 27 Aug 2026 18:28:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787880530; x=1788485330; h=content-type:to:from:subject:message-id:in-reply-to:date :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to:content-type; bh=lxsp0z9HP23MQDM7Mt1YLo61kRgSyqCYkKGFcgLyq/E=; b=gyGkSGo5Spj26fhPtWSdgnsgNNmw0rskB9H1dWcDPesPgfCtZpSEysrv3IpamhXw9J 19hdxzkIfvly1rM/YPXCSgnrvxqEV4G3os7dPgqFc1GTJaCywLFtR4w28hRd4RG25y8O LgYhIwqXh0rquEjBZksno7WsfI2koUdc5DY3kBisAUNuVMVn56XxHV+crd866DDQBmUP iiv/RrOo7UoUw8m2LfXd4TmI4tmkY9Jpa0wlVTnbxW+nCnI3Rv+8nmvnWgWq/LWt/jHw QgIcF0FGh4EdSdnVmF18QBe275MQ/OYwjWKK3loOOFex8/EqNmsjjldi5saRFdKcRQzJ mHBg== X-Gm-Message-State: AFuF++nAh2/phLKo7PooNd0RsTJQ6Pg88uOidLRApDsbVnc8iCgF3Zc+ vOGWPCsRuB5Uo4RAiH42Dl3meUOkIC41R9jDaZd2Wga/JlzIRc+YKmyJbrYy6qwmCUpVPmnuxKA 05mu550a5Ev3vwvUc71T8Y8eA3LX2FUS2qnIWD8c1coNuvB85Mep4oOuvjsM= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6809:404:b0:4b3:98f4:f057 with SMTP id 5614622812f47-4b398f4f0b7mr3160030b6e.3.1787880529984; Thu, 27 Aug 2026 18:28:49 -0700 (PDT) Date: Thu, 27 Aug 2026 18:28:49 -0700 In-Reply-To: <6a9087a4.4d659fcc.734b4.0013.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a90e451.1d9ded08.62e62.00e0.GAE@google.com> Subject: Forwarded: [PATCH] usb: serial: keyspan: add debug prints to trace NULL p_priv From: syzbot To: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" For archival purposes, forwarding an incoming command email to linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com. *** Subject: [PATCH] usb: serial: keyspan: add debug prints to trace NULL p_priv Author: kartikey406@gmail.com #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master Add pr_info() calls in keyspan_break_ctl() and keyspan_port_remove() to trace the lifetime of the per-port private data (p_priv) around port removal. This is a debugging aid to confirm a suspected race where a port is unbound (freeing p_priv) while a stale tty fd is still open, leading to a NULL pointer dereference in keyspan_break_ctl() when break_ctl is issued afterward. Not for upstream inclusion - debug only. Link: https://syzkaller.appspot.com/bug?extid=473d7477c523b41d4046 Signed-off-by: Deepanshu Kartikey --- drivers/usb/serial/keyspan.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/usb/serial/keyspan.c b/drivers/usb/serial/keyspan.c index 4d3746c7a94e..36626c0cc0a9 100644 --- a/drivers/usb/serial/keyspan.c +++ b/drivers/usb/serial/keyspan.c @@ -601,9 +601,9 @@ static int keyspan_break_ctl(struct tty_struct *tty, int break_state) { struct usb_serial_port *port = tty->driver_data; struct keyspan_port_private *p_priv; - p_priv = usb_get_serial_port_data(port); - + pr_info("keyspan: break_ctl port=%d p_priv=%px disconnected=%d\n", + port->port_number, p_priv, port->serial->disconnected); if (break_state == -1) p_priv->break_on = 1; else @@ -2975,7 +2975,8 @@ static void keyspan_port_remove(struct usb_serial_port *port) int i; p_priv = usb_get_serial_port_data(port); - + pr_info("keyspan: port_remove port=%d freeing p_priv=%px\n", + port->port_number, p_priv); usb_kill_urb(p_priv->inack_urb); usb_kill_urb(p_priv->outcont_urb); for (i = 0; i < 2; i++) { -- 2.43.0