From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 EADCC14A0A5 for ; Mon, 22 Apr 2024 13:00:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713790843; cv=none; b=l7fNKTgp7ha5DwXh/CK00SPvgmrsNKxezZXnnFTuZYC9etg0pvUh/xlaPLzm9FvrbV2yYKg65PdRaeGAAZDdx67iPv2ciJg2TzLjIUssatPKZt8c6swPpnoPfYZgp2raYrLOGEoiZS9HVGQKAQ8sZFh63R6vQaeOylUddexvWNk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713790843; c=relaxed/simple; bh=SDxNTBSTL9jCN8hAO973y/hKD0LsH3tdFBWk8ED5n6s=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=QNUmDwPXdiMcKMFuX10f3BKuT/XtkEvZs6sJPGk3cTYEW1yWc1+Q0gdRemT/J/9qnA4j5bl4nM+1A8dpv9iC+ZLqAc8XkoHaqFDI6lQteD143YNaG23eVIlHl2p3a8RjkjmRr6pW1eYviP3XiXQaf5NSTPWEWo8r86ljWN1GP50= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=cmg/OjHR; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="cmg/OjHR" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1713790840; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=G10E+2rDdWDG1Uk1Q5OYi9q5kLjqZHfV9ll1BpGSLpA=; b=cmg/OjHRD7feEmIlmGzduWXI5i1HLsB7ZQ+xc5pMV5zDcFU5TwF8Oe8bVZuyg7KyATwXnq R+X60K2/T9KOWclkoExRgpKIc4D7w+oKoZO9Cyzfg1HlL4fl9+urET2R6AkUq5Q4Eu40Y+ eguQBbMmmODx9mSTY14aXP5VP0UwZOI= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-529-4dxWiTLTNDOYGNZvn7IlWQ-1; Mon, 22 Apr 2024 09:00:34 -0400 X-MC-Unique: 4dxWiTLTNDOYGNZvn7IlWQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 151F68021A5; Mon, 22 Apr 2024 13:00:34 +0000 (UTC) Received: from localhost (unknown [10.39.195.50]) by smtp.corp.redhat.com (Postfix) with ESMTP id D4B93100A841; Mon, 22 Apr 2024 13:00:32 +0000 (UTC) Date: Mon, 22 Apr 2024 09:00:31 -0400 From: Stefan Hajnoczi To: Jeongjun Park Cc: mst@redhat.com, jasowang@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, sgarzare@redhat.com, syzbot+6c21aeb59d0e82eb2782@syzkaller.appspotmail.com, syzkaller-bugs@googlegroups.com, virtualization@lists.linux.dev, Arseny Krasnov Subject: Re: [PATCH virt] virt: fix uninit-value in vhost_vsock_dev_open Message-ID: <20240422130031.GA77895@fedora> References: <20240420060450-mutt-send-email-mst@kernel.org> <20240421030606.80385-1-aha310510@gmail.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="fbjDzR1gbQWxLtRv" Content-Disposition: inline In-Reply-To: <20240421030606.80385-1-aha310510@gmail.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 --fbjDzR1gbQWxLtRv Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Apr 21, 2024 at 12:06:06PM +0900, Jeongjun Park wrote: > static bool vhost_transport_seqpacket_allow(u32 remote_cid) > { > .... > vsock =3D vhost_vsock_get(remote_cid); >=20 > if (vsock) > seqpacket_allow =3D vsock->seqpacket_allow; > .... > } >=20 > I think this is due to reading a previously created uninitialized=20 > vsock->seqpacket_allow inside vhost_transport_seqpacket_allow(),=20 > which is executed by the function pointer present in the if statement. CCing Arseny, author of commit ced7b713711f ("vhost/vsock: support SEQPACKET for transport"). Looks like a genuine bug in the commit. vhost_vsock_set_features() sets seqpacket_allow to true when the feature is negotiated. The assumption is that the field defaults to false. The rest of the vhost_vsock.ko code is written to initialize the vhost_vsock fields, so you could argue seqpacket_allow should just be explicitly initialized to false. However, eliminating this class of errors by zeroing seems reasonable in this code path. vhost_vsock_dev_open() is not performance-critical. Acked-by: Stefan Hajnoczi --fbjDzR1gbQWxLtRv Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmYmX24ACgkQnKSrs4Gr c8g0xgf9GAsOG1fK6cXKiusz/7vFucJOezY6SjiRsy4zMiPpUTRRsDAiaA6akyQ6 5Bnmnr1HjGGwXOeROMJfGWohjhlMCsKKCSiWT8rnPOOIQsw5yc6tgd2aqmtmbD3q APFtGlvHmQwlRE/6/aAvkoUoTMQuS3pL3pKQqKNDgboo+lJAdKp97SiOypeLxiZ1 dYYtujTVn46aivjD/Sdm731fGFRadB/1cBPLlDioac/22TmBckx2cpOhxC3Ggoo3 tYXRtVSMb0ICOBe2Krf2sE+TqAr96/JF8DFWlag5040Bp1VfoO54OfbnvPDtu3bG gQF5MIPjdLy7jk1A50VuhR7p7ILV6A== =pV2Q -----END PGP SIGNATURE----- --fbjDzR1gbQWxLtRv--