From patchwork Wed Mar 9 00:21:34 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 594425 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id A232B1401AF; Wed, 9 Mar 2016 11:22:07 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1adRt6-0001mm-Ev; Wed, 09 Mar 2016 00:22:04 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1adRsl-0001a9-O6 for kernel-team@lists.ubuntu.com; Wed, 09 Mar 2016 00:21:43 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1adRsl-0002fc-A5; Wed, 09 Mar 2016 00:21:43 +0000 Received: from kamal by fourier with local (Exim 4.86) (envelope-from ) id 1adRsi-0005Vo-Km; Tue, 08 Mar 2016 16:21:40 -0800 From: Kamal Mostafa To: Takashi Iwai Subject: [3.19.y-ckt stable] Patch "ALSA: seq: Fix race at closing in virmidi driver" has been added to the 3.19.y-ckt tree Date: Tue, 8 Mar 2016 16:21:34 -0800 Message-Id: <1457482894-21153-1-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.0 X-Extended-Stable: 3.19 Cc: Kamal Mostafa , kernel-team@lists.ubuntu.com, Dmitry Vyukov X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled ALSA: seq: Fix race at closing in virmidi driver to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue This patch is scheduled to be released in version 3.19.8-ckt16. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.19.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ---8<------------------------------------------------------------ From 1f81e6fd5aa7aafe4f4f756491523b65d20231c2 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Mon, 1 Feb 2016 12:06:42 +0100 Subject: ALSA: seq: Fix race at closing in virmidi driver commit 2d1b5c08366acd46c35a2e9aba5d650cb5bf5c19 upstream. The virmidi driver has an open race at closing its assigned rawmidi device, and this may lead to use-after-free in snd_seq_deliver_single_event(). Plug the hole by properly protecting the linked list deletion and calling in the right order in snd_virmidi_input_close(). BugLink: http://lkml.kernel.org/r/CACT4Y+Zd66+w12fNN85-425cVQT=K23kWbhnCEcMB8s3us-Frw@mail.gmail.com Reported-by: Dmitry Vyukov Tested-by: Dmitry Vyukov Signed-off-by: Takashi Iwai Signed-off-by: Kamal Mostafa --- sound/core/seq/seq_virmidi.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) -- 2.7.0 diff --git a/sound/core/seq/seq_virmidi.c b/sound/core/seq/seq_virmidi.c index 56e0f4cd..f297592 100644 --- a/sound/core/seq/seq_virmidi.c +++ b/sound/core/seq/seq_virmidi.c @@ -254,9 +254,13 @@ static int snd_virmidi_output_open(struct snd_rawmidi_substream *substream) */ static int snd_virmidi_input_close(struct snd_rawmidi_substream *substream) { + struct snd_virmidi_dev *rdev = substream->rmidi->private_data; struct snd_virmidi *vmidi = substream->runtime->private_data; - snd_midi_event_free(vmidi->parser); + + write_lock_irq(&rdev->filelist_lock); list_del(&vmidi->list); + write_unlock_irq(&rdev->filelist_lock); + snd_midi_event_free(vmidi->parser); substream->runtime->private_data = NULL; kfree(vmidi); return 0;