On Tue, Aug 05, 2025 at 01:10:09PM +0800, [email protected] wrote:
From: Henry Martin <[email protected]>

The `struct virtio_vsock_pkt_info` is declared on the stack but only
partially initialized (only `op`, `flags`, and `vsk` are set)

The uninitialized fields (including `pkt_len`, `remote_cid`,
`remote_port`, etc.) contain residual kernel stack data. This structure
is passed to `virtio_transport_send_pkt_info()`, which uses the
uninitialized fields.

Fixes: 06a8fc78367d ("VSOCK: Introduce virtio_vsock_common.ko")
Reported-by: TCS Robot <[email protected]>
Signed-off-by: Henry Martin <[email protected]>
---
net/vmw_vsock/virtio_transport_common.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/net/vmw_vsock/virtio_transport_common.c 
b/net/vmw_vsock/virtio_transport_common.c
index fe92e5fa95b4..cb391a98d025 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -1073,14 +1073,14 @@ EXPORT_SYMBOL_GPL(virtio_transport_connect);

int virtio_transport_shutdown(struct vsock_sock *vsk, int mode)
{
-       struct virtio_vsock_pkt_info info = {
-               .op = VIRTIO_VSOCK_OP_SHUTDOWN,
-               .flags = (mode & RCV_SHUTDOWN ?
-                         VIRTIO_VSOCK_SHUTDOWN_RCV : 0) |
-                        (mode & SEND_SHUTDOWN ?
-                         VIRTIO_VSOCK_SHUTDOWN_SEND : 0),
-               .vsk = vsk,
-       };

The compiler sets all other fields to 0, so I don't understand what this patch solves.
Can you give an example of the problem you found?

Furthermore, even if this fix were valid, why do it for just one function?

Stefano

+       struct virtio_vsock_pkt_info info = {0};
+
+       info.op = VIRTIO_VSOCK_OP_SHUTDOWN;
+       info.flags = (mode & RCV_SHUTDOWN ?
+                       VIRTIO_VSOCK_SHUTDOWN_RCV : 0) |
+                       (mode & SEND_SHUTDOWN ?
+                       VIRTIO_VSOCK_SHUTDOWN_SEND : 0);
+       info.vsk = vsk;

        return virtio_transport_send_pkt_info(vsk, &info);
}
--
2.41.3



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