From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793210908; b=e7mhG2PrW8TBPVkmM8cKbv8g3B8gjgO0AEwcG4hHWHWXUEWLXcR6kgRfKxYyASECMrax nA4wYE2/5hKIcPZAgsVGC650jVpSqvthJEJji42ZttR6TYp2zPxv7u/xq4ZWNVLiFUk5K KZcP38dB0iin7jnoAqgys9Lmq0AYXV3/xOJkZBA9kb5eac4tHWask/gCk3yK6vxLahBo1 NGDlHlEJYtPw1g99SaTln6sB7XOOY8zWxNJVP3p6FSg5T8BgMtbLzZiVR5GJU3wIVOUyQ 4EAMfWoU8h/V3QGqzhrT+MiDlt23jHMB9qqfXWeeruylTW5Sm8XKCa0jxRQ9Pf5EA+Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793210908; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=TCLT7vbs33K4OIlcRiKFwkeJh8BUUCUk5G+fkM0voOQ=; b=pbVvWihsv2/MrXX6DWxlYQw9qEDQOCFzsmn84cwfymN01fmRW47VVcJU/K21tXefKY8p hfxAGZh6PgVKn5aPag9ZDQTexbHvBwT58Uxl7NFsQspf799w4PhF7i8GSP9muL/E1INQD YG844IsiaIjsBnXtDKhSbPgSZnWnBikCGykMVhG6J3N8+0z3fZhKc5xoKqb2Ko+efqa6E U60HBTsBV3rzi1lqjQ1ZueHVhuYAnLed5sb35CTCppZRgFzMbKmd9AKku0ZeMFjMNo88c tPcBA12w+NW4t4kpJ3glxMpxB9BT7gJEKOwBhMn9A7oPLDnp73GbGgfMzoTdNPsXejA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=vE4OkUvh; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D0BE5606A31D; Wed, 28 Oct 2026 18:08:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=vE4OkUvh Received: by smtp.kernel.org (Postfix) with ESMTPSA id 317511F01825; Wed, 28 Oct 2026 18:08:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793210907; bh=TCLT7vbs33K4OIlcRiKFwkeJh8BUUCUk5G+fkM0voOQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=vE4OkUvhEiDBHfp17zGJs6nYpdtwB0PeHq6bXh+LBQkE0BbnsFG6ihUbcPpS8hQY7 EdvUJ+cw4nrkWSbkS4KHotJxmnBybRs8VkR7BTcmi5BtceeZnrNIL3ozChHpkfA55u QeEv6q+cHbLYQgMvMXLeDoL9adBP1bNnGBIUjv90= 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 5.15 192/571] kgdboc: Fix tty driver reference leak in configure_kgdboc() Date: Wed, 28 Oct 2026 17:55:39 +0100 Message-ID: <20261028170012.565282872@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170008.009143722@linuxfoundation.org> References: <20261028170008.009143722@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-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 @@ -190,6 +190,11 @@ static void cleanup_kgdboc(void) return; 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) @@ -250,6 +255,10 @@ nmi_con_failed: kgdb_unregister_io_module(&kgdboc_io_ops); noconfig: kgdboc_unregister_kbd(); + if (kgdb_tty_driver) { + tty_driver_kref_put(kgdb_tty_driver); + kgdb_tty_driver = NULL; + } configured = 0; return err;