From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754780AbdJPQNE (ORCPT ); Mon, 16 Oct 2017 12:13:04 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:33636 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754469AbdJPQNB (ORCPT ); Mon, 16 Oct 2017 12:13:01 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dmitry Vyukov , Takashi Iwai , Mark Salyzyn Subject: [PATCH 3.18 19/19] ALSA: seq: Fix missing NULL check at remove_events ioctl Date: Mon, 16 Oct 2017 18:12:10 +0200 Message-Id: <20171016160922.985884106@linuxfoundation.org> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20171016160922.020176454@linuxfoundation.org> References: <20171016160922.020176454@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Takashi Iwai commit 030e2c78d3a91dd0d27fef37e91950dde333eba1 upstream. snd_seq_ioctl_remove_events() calls snd_seq_fifo_clear() unconditionally even if there is no FIFO assigned, and this leads to an Oops due to NULL dereference. The fix is just to add a proper NULL check. Reported-by: Dmitry Vyukov Tested-by: Dmitry Vyukov Signed-off-by: Takashi Iwai Cc: Mark Salyzyn Cc: Dmitry Vyukov Signed-off-by: Greg Kroah-Hartman --- sound/core/seq/seq_clientmgr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/sound/core/seq/seq_clientmgr.c +++ b/sound/core/seq/seq_clientmgr.c @@ -1970,7 +1970,7 @@ static int snd_seq_ioctl_remove_events(s * No restrictions so for a user client we can clear * the whole fifo */ - if (client->type == USER_CLIENT) + if (client->type == USER_CLIENT && client->data.user.fifo) snd_seq_fifo_clear(client->data.user.fifo); }