The NBD spec says that behavior is unspecified if the client
requests 0 length for block status; but since the structured
reply is documenting as returning a non-zero length, it's
easier to just diagnose this with an EINVAL error than to
figure out what to return.
CC: qemu-sta...@nongnu.org
Signed-off-by: Eric Blake <ebl...@redhat.com>
---
nbd/server.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/nbd/server.c b/nbd/server.c
index 9e1f2271784..493a926e063 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -2007,6 +2007,10 @@ static coroutine_fn int nbd_handle_request(NBDClient
*client,
"discard failed", errp);
case NBD_CMD_BLOCK_STATUS:
+ if (!request->len) {
+ return nbd_send_generic_reply(client, request->handle, -EINVAL,
+ "need non-zero length", errp);
+ }
if (client->export_meta.valid && client->export_meta.base_allocation) {
return nbd_co_send_block_status(client, request->handle,
blk_bs(exp->blk), request->from,
--
2.14.4
