[PATCH v2 8/8] io/channel-socket: qio_channel_socket_flush(): improve msg validation

[Vladimir Sementsov-Ogievskiy]

For SO_EE_ORIGIN_ZEROCOPY the 32-bit notification range is encoded
as [ee_info, ee_data] inclusively, so ee_info should be less or
equal to ee_data.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@yandex-team.ru>
---
 io/channel-socket.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/io/channel-socket.c b/io/channel-socket.c
index 02ffb51e99..3a899b0608 100644
--- a/io/channel-socket.c
+++ b/io/channel-socket.c
@@ -782,6 +782,11 @@ static int qio_channel_socket_flush(QIOChannel *ioc,
                              "Error not from zero copy");
             return -1;
         }
+        if (serr->ee_data < serr->ee_info) {
+            error_setg_errno(errp, serr->ee_origin,
+                             "Wrong notification bounds");
+            return -1;
+        }
 
         /* No errors, count successfully finished sendmsg()*/
         sioc->zero_copy_sent += serr->ee_data - serr->ee_info + 1;
-- 
2.34.1