From 3062cb100787a9ddf45de30004b962035cd497fb Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 22 Apr 2024 10:03:13 -0400 Subject: [PATCH] vhost/vsock: always initialize seqpacket_allow MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit 1e1fdcbdde3b7663e5d8faeb2245b9b151417d22 ] There are two issues around seqpacket_allow: 1. seqpacket_allow is not initialized when socket is created. Thus if features are never set, it will be read uninitialized. 2. if VIRTIO_VSOCK_F_SEQPACKET is set and then cleared, then seqpacket_allow will not be cleared appropriately (existing apps I know about don't usually do this but it's legal and there's no way to be sure no one relies on this). To fix: - initialize seqpacket_allow after allocation - set it unconditionally in set_features Reported-by: syzbot+6c21aeb59d0e82eb2782@syzkaller.appspotmail.com Reported-by: Jeongjun Park Fixes: ced7b713711f ("vhost/vsock: support SEQPACKET for transport"). Tested-by: Arseny Krasnov Cc: David S. Miller Cc: Stefan Hajnoczi Message-ID: <20240422100010-mutt-send-email-mst@kernel.org> Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Reviewed-by: Stefano Garzarella Reviewed-by: Eugenio Pérez Acked-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/vhost/vsock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 1f3b89c885cc..c00f5821d6ec 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -654,6 +654,7 @@ static int vhost_vsock_dev_open(struct inode *inode, struct file *file) } vsock->guest_cid = 0; /* no CID assigned yet */ + vsock->seqpacket_allow = false; atomic_set(&vsock->queued_replies, 0); @@ -797,8 +798,7 @@ static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features) goto err; } - if (features & (1ULL << VIRTIO_VSOCK_F_SEQPACKET)) - vsock->seqpacket_allow = true; + vsock->seqpacket_allow = features & (1ULL << VIRTIO_VSOCK_F_SEQPACKET); for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { vq = &vsock->vqs[i];