From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759091Ab0JVSzz (ORCPT ); Fri, 22 Oct 2010 14:55:55 -0400 Received: from kroah.org ([198.145.64.141]:33875 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759120Ab0JVSzv (ORCPT ); Fri, 22 Oct 2010 14:55:51 -0400 X-Mailbox-Line: From gregkh@clark.site Fri Oct 22 11:52:27 2010 Message-Id: <20101022185227.854068545@clark.site> User-Agent: quilt/0.48-11.2 Date: Fri, 22 Oct 2010 11:50:40 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Clemens Ladisch , Takashi Iwai Subject: [006/103] ALSA: rawmidi: fix oops (use after free) when unloading a driver module In-Reply-To: <20101022185455.GA9114@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.35-stable review patch. If anyone has any objections, please let us know. ------------------ From: Clemens Ladisch commit aa73aec6c385e2c797ac25cc7ccf0318031de7c8 upstream. When a driver module is unloaded and the last still open file is a raw MIDI device, the card and its devices will be actually freed in the snd_card_file_remove() call when that file is closed. Afterwards, rmidi and rmidi->card point into freed memory, so the module pointer is likely to be garbage. (This was introduced by commit 9a1b64caac82aa02cb74587ffc798e6f42c6170a.) Signed-off-by: Clemens Ladisch Reported-by: Krzysztof Foltman Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/core/rawmidi.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/sound/core/rawmidi.c +++ b/sound/core/rawmidi.c @@ -535,13 +535,15 @@ static int snd_rawmidi_release(struct in { struct snd_rawmidi_file *rfile; struct snd_rawmidi *rmidi; + struct module *module; rfile = file->private_data; rmidi = rfile->rmidi; rawmidi_release_priv(rfile); kfree(rfile); + module = rmidi->card->module; snd_card_file_remove(rmidi->card, file); - module_put(rmidi->card->module); + module_put(module); return 0; }