From: Xie Yongji
stable inclusion
from linux-4.19.198
commit b5fba782ccd3d12a14f884cd20f255fc9c0eec0c
category: bugfix
issue: #I49EFH
CVE: CVE-2021-38160
--------------------------------
[ Upstream commit d00d8da5869a2608e97cfede094dfc5e11462a46 ]
The buf->len might come from an untrusted device. This
ensures the value would not exceed the size of the buffer
to avoid data corruption or loss.
Signed-off-by: Xie Yongji
Acked-by: Jason Wang
Link: https://lore.kernel.org/r/20210525125622.1203-1-xieyongji@bytedance.com
Signed-off-by: Michael S. Tsirkin
Signed-off-by: Sasha Levin
Signed-off-by: Yang Yingliang
Signed-off-by: Yu Changchun
---
drivers/char/virtio_console.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index ca71ee939533..cdf441942bae 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -488,7 +488,7 @@ static struct port_buffer *get_inbuf(struct port *port)
buf = virtqueue_get_buf(port->in_vq, &len);
if (buf) {
- buf->len = len;
+ buf->len = min_t(size_t, len, buf->size);
buf->offset = 0;
port->stats.bytes_received += len;
}
@@ -1738,7 +1738,7 @@ static void control_work_handler(struct work_struct *work)
while ((buf = virtqueue_get_buf(vq, &len))) {
spin_unlock(&portdev->c_ivq_lock);
- buf->len = len;
+ buf->len = min_t(size_t, len, buf->size);
buf->offset = 0;
handle_control_message(vq->vdev, portdev, buf);
--
2.22.0
