[Libguestfs] [nbdkit PATCH 2/5] protocol: Validate request flags
Reject rather than silently ignoring unknown client request flags.
Signed-off-by: Eric Blake <eblake(a)redhat.com>
---
src/connections.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/src/connections.c b/src/connections.c
index 16c6584..44b7530 100644
--- a/src/connections.c
+++ b/src/connections.c
@@ -546,6 +546,13 @@ validate_request (struct connection *conn,
return 0;
}
+ /* Validate flags */
+ if (flags & ~NBD_CMD_FLAG_FUA) {
+ nbdkit_error ("invalid request: unknown flag (0x%x)", flags);
+ *error = EINVAL;
+ return 0;
+ }
+
/* Refuse over-large read and write requests. */
if ((cmd == NBD_CMD_WRITE || cmd == NBD_CMD_READ) &&
count > MAX_REQUEST_SIZE) {
@@ -741,7 +748,7 @@ recv_request_send_reply (struct connection *conn)
}
cmd = be32toh (request.type);
- flags = cmd;
+ flags = cmd & ~NBD_CMD_MASK_COMMAND;
cmd &= NBD_CMD_MASK_COMMAND;
offset = be64toh (request.offset);
--
2.9.3