Received-SPF: softfail (google.com: domain of transitioning linux-crypto-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
From:   Jason Wang <jasowang@redhat.com>
To:     mst@redhat.com, mpm@selenic.com, herbert@gondor.apana.org.au
Cc:     linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
        lvivier@redhat.com, Jason Wang <jasowang@redhat.com>,
        syzbot+5b59d6d459306a556f54@syzkaller.appspotmail.com
Subject: [PATCH] virtio-rng: make device ready before making request
Date:   Wed,  8 Jun 2022 14:14:22 +0800
Message-Id: <20220608061422.38437-1-jasowang@redhat.com>
MIME-Version: 1.0
Content-type: text/plain
Content-Transfer-Encoding: 8bit
Precedence: bulk

Current virtio-rng does a entropy request before DRIVER_OK, this
violates the spec and kernel will ignore the interrupt after commit
8b4ec69d7e09 ("virtio: harden vring IRQ").

Fixing this by making device ready before the request.

Fixes: 8b4ec69d7e09 ("virtio: harden vring IRQ")
Reported-and-tested-by: syzbot+5b59d6d459306a556f54@syzkaller.appspotmail.com
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/char/hw_random/virtio-rng.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index e856df7e285c..a6f3a8a2aca6 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -159,6 +159,8 @@ static int probe_common(struct virtio_device *vdev)
 		goto err_find;
 	}
 
+	virtio_device_ready(vdev);
+
 	/* we always have a pending entropy request */
 	request_entropy(vi);
 
-- 
2.25.1