6.6-stable review patch. If anyone has any objections, please let me know.
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From: Michael S. Tsirkin mst@redhat.com
[ 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 aha310510@gmail.com Fixes: ced7b713711f ("vhost/vsock: support SEQPACKET for transport"). Tested-by: Arseny Krasnov arseny.krasnov@kaspersky.com Cc: David S. Miller davem@davemloft.net Cc: Stefan Hajnoczi stefanha@redhat.com Message-ID: 20240422100010-mutt-send-email-mst@kernel.org Signed-off-by: Michael S. Tsirkin mst@redhat.com Acked-by: Jason Wang jasowang@redhat.com Reviewed-by: Stefano Garzarella sgarzare@redhat.com Reviewed-by: Eugenio Pérez eperezma@redhat.com Acked-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 61255855d4906..d94a06008ff64 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -656,6 +656,7 @@ 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);
@@ -799,8 +800,7 @@ 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];