vquic: do_sendmsg full init

When passing a `msg_ctrl` to sendmsg() as part of GSO handling, zero the
complete array. This fixes any false positives by valgrind that complain
about uninitialised memory, even though the kernel only ever accesses
the first two bytes.

Reported-by: Aleksei Bavshin
Fixes #19714
Closes #19715

diff --git a/lib/vquic/vquic.c b/lib/vquic/vquic.c
index 562a99e4fee03de941547dcfc014a1d360c71eb7..aa0011c577c4ce149213d1f64bbdc8dc28bdba9e 100644 (file)
--- a/lib/vquic/vquic.c
+++ b/lib/vquic/vquic.c
@@ -145,6 +145,7 @@ static CURLcode do_sendmsg(struct Curl_cfilter *cf,
   if(pktlen > gsolen) {
     /* Only set this, when we need it. macOS, for example,
      * does not seem to like a msg_control of length 0. */
+    memset(msg_ctrl, 0, sizeof(msg_ctrl));
     msg.msg_control = msg_ctrl;
     assert(sizeof(msg_ctrl) >= CMSG_SPACE(sizeof(int)));
     msg.msg_controllen = CMSG_SPACE(sizeof(int));