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 5767C42EEDD; Mon, 17 Aug 2026 14:57:45 +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=1786978666; cv=none; b=ofGr5Oxp5R8J5vtSO8G8CmSxHqHpNeUovLEKd4oKNE/eEd707tfacye3MSl6n2n/JziHwk2uFEoEV8lAi+LeBNmEZhQWg2sW4jNCQtrJXjrSbFk6LvZQfnNSOQdLr6lqk82l/23Zd2d2YG2Hy/JehUakkJG3BIZCO5SH+Ceg/SQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786978666; c=relaxed/simple; bh=EQfQqqJteCZ/J6kdzn8Bhfz/43BJkcGCJOgfcC0OT6A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ANbsvRqzmoLq0iQ4MWVrp5uhyUN4OeGB8Dby+mWS0NMYkx1bPoTo1HRRvr/Zxd5VAw4Oknc8qmZDcKx7QJnuKUsscixDAGXiTQHaVuNfRqVHqNKq5eOL9INAj9RxDbtxh74e66vuz2Mds84T1H+3SVOXBxOY8a12Cj2HfjnznLA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mZgOwlcV; 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="mZgOwlcV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF3551F000E9; Mon, 17 Aug 2026 14:57:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786978665; bh=Upakjp+85oAsiY897aPBc2ixrOrJBqtT0bVTzIZAWzk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=mZgOwlcVEOeVXOJZNUQreQ9Y2D9IcKao5Y3F+nmbiOAJkkqpVhBPmxNC/zy6MZTwe 4X+3pI+6mSIXpgou4tQV/Kkfieo0K3+ZQo+w19gkt0Kkt2r6ze0M1z1k19nbko4/ED k1Ny63IQsSh/lx9+0vHGO0J8ofYQBe/42c/8FNF4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+565b1138cfbe549d4422@syzkaller.appspotmail.com, Takashi Iwai Subject: [PATCH 6.6 114/156] ALSA: usb: Fix UAF at delayed release of MIDI2 EPs Date: Mon, 17 Aug 2026 15:34:08 +0200 Message-ID: <20260817132539.091426803@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817132534.666299318@linuxfoundation.org> References: <20260817132534.666299318@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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Takashi Iwai commit f8a80cfb68613fb7e6452b66447dbc63f435d140 upstream. The recent fix for UAF in ump_to_endpoint() caused another UAF because it tries to dereference the UMP endpoint object, but this might be executed at a delayed context where the endpoint has been already released. Add private_free to clear the associated data for avoiding the further dereference for delayed releases. Fixes: 4a05b2d1b464 ("ALSA: usb-audio: fix use-after-free in ump_to_endpoint()") Reported-by: syzbot+565b1138cfbe549d4422@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=565b1138cfbe549d4422 Cc: Link: https://patch.msgid.link/20260808152009.1947835-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/usb/midi2.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/sound/usb/midi2.c +++ b/sound/usb/midi2.c @@ -695,6 +695,14 @@ static int parse_midi_2_0_endpoints(stru return 0; } +static void free_ump_private_data(struct snd_ump_endpoint *ump) +{ + struct snd_usb_midi2_ump *rmidi = ump->private_data; + + if (rmidi) + rmidi->ump = NULL; +} + static void free_all_midi2_umps(struct snd_usb_midi2_interface *umidi) { struct snd_usb_midi2_ump *rmidi; @@ -745,6 +753,7 @@ static int create_midi2_ump(struct snd_u ump->private_data = rmidi; ump->ops = &snd_usb_midi_v2_ump_ops; + ump->private_free = free_ump_private_data; rmidi->eps[STR_IN] = ep_in; rmidi->eps[STR_OUT] = ep_out;