1 files changed, 12 insertions, 0 deletions
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index b0e445d6bd..c63f549f39 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -1363,8 +1363,20 @@ static void coroutine_fn v9fs_version(void *opaque)
         s->proto_version = V9FS_PROTO_2000L;
     } else {
         v9fs_string_sprintf(&version, "unknown");
+        /* skip min. msize check, reporting invalid version has priority */
+        goto marshal;
     }
 
+    if (s->msize < P9_MIN_MSIZE) {
+        err = -EMSGSIZE;
+        error_report(
+            "9pfs: Client requested msize < minimum msize ("
+            stringify(P9_MIN_MSIZE) ") supported by this server."
+        );
+        goto out;
+    }
+
+marshal:
     err = pdu_marshal(pdu, offset, "ds", s->msize, &version);
     if (err < 0) {
         goto out;