From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C07801A682B; Fri, 9 Oct 2026 14:26:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791555989; cv=none; b=q4Kp596YyTK6Gk13XZQwOsiqrlcedKjHdVHgpt5JyhIOIjs3lxXnpDp3X35JWhWBVa7Rh3ZL6v21c/c9ieLnnCktn8Jw3rwhG8f2jmE+vh76zMG1+1gY8+btO0r0oU/qVdgVdHS4dCySP3s0ByOA4RmGkSnUdbOb2ljMMQmZCW4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791555989; c=relaxed/simple; bh=XF68xoxHqIKdarV28Sk+Wj0/BotWlmxYNhsm5euQMnA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NXbSysZvteLJdNKbTpdfJbu0qyK/u4Fdl2uFyxOlnYVelG7SEa9iC19SQuqpsvSgiUd4Q8bJ/2cIB55jn3OLUjwHL0sTAwZHeYwHZU+isa97J2eIpwwmMcWSc7RVY8S6QdWuhcwPM3dPWK79coKpIKDDh7h+e36GeczzxqVHzOE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=FtirS8dn; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="FtirS8dn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2BE2D1F000FF; Fri, 9 Oct 2026 14:26:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791555988; bh=2cNmJ/gCzN9GRRYOnKI2eFF0bMZircMvb51pHzt0MvA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=FtirS8dnSdT8QHuVvJvfgpm5k19g81RPWy/708/rKfedID3r9N/lbqXoqqRrc85bH Iz8rbsfrlwkrNCt6B+zk42VynE+nefC+7gbxkF2JbuJJwat1iTRGvfZLv+cLbzuIPT Qf+dgdUaFrK+TVqP40iPdaDvjh3256xxqoO2t5P8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable@kernel.org, Wentao Liang , Douglas Anderson Subject: [PATCH 6.18 150/403] kgdboc: Fix tty driver reference leak in configure_kgdboc() Date: Fri, 9 Oct 2026 16:08:31 +0200 Message-ID: <20261009140955.580371871@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261009140952.119038291@linuxfoundation.org> References: <20261009140952.119038291@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wentao Liang commit ef3134cd0d4831ae2137aee2883987859b80b2c6 upstream. tty_find_polling_driver() returns the tty driver with an extra reference taken by tty_driver_kref_get(). configure_kgdboc() stores it in kgdb_tty_driver but the reference is never dropped: it is leaked when kgdb_register_io_module() fails, when the configuration is cleared, and on every reconfigure. Release the reference both when unconfiguring and on the error path. Fixes: 7d7b93c1452f ("tty: kref the tty driver object") Cc: stable@kernel.org Signed-off-by: Wentao Liang Reviewed-by: Douglas Anderson Link: https://patch.msgid.link/20260917155523.2161202-1-vulab@iscas.ac.cn Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/kgdboc.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/drivers/tty/serial/kgdboc.c +++ b/drivers/tty/serial/kgdboc.c @@ -188,6 +188,11 @@ static void cleanup_kgdboc(void) kgdboc_unregister_kbd(); kgdb_unregister_io_module(&kgdboc_io_ops); + + if (kgdb_tty_driver) { + tty_driver_kref_put(kgdb_tty_driver); + kgdb_tty_driver = NULL; + } } static int configure_kgdboc(void) @@ -254,6 +259,10 @@ do_register: noconfig: kgdboc_unregister_kbd(); + if (kgdb_tty_driver) { + tty_driver_kref_put(kgdb_tty_driver); + kgdb_tty_driver = NULL; + } configured = 0; return err;