krb5 commit [krb5-1.10]: Check for negative poll timeout in k5_sendto_kdc

[Tom Yu]

https://github.com/krb5/krb5/commit/4fcd8cea7ee1594c25b9e7eec42ae3ce6775d93a
commit 4fcd8cea7ee1594c25b9e7eec42ae3ce6775d93a
Author: Greg Hudson <ghudson at mit.edu>
Date:   Fri Jan 25 13:11:27 2013 -0500

    Check for negative poll timeout in k5_sendto_kdc
    
    (cherry picked from commit 74bee54227deb64a41c2e79f57dd2a2c5ea010a3)
    
    ticket: 7578 (new)
    version_fixed: 1.10.4
    status: resolved

 src/lib/krb5/os/sendto_kdc.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/src/lib/krb5/os/sendto_kdc.c b/src/lib/krb5/os/sendto_kdc.c
index 63dbcd8..7ee5951 100644
--- a/src/lib/krb5/os/sendto_kdc.c
+++ b/src/lib/krb5/os/sendto_kdc.c
@@ -523,6 +523,10 @@ cm_select_or_poll(const struct select_state *in, struct select_state *out,
             return e;
         timeout = (in->end_time.tv_sec - now.tv_sec) * 1000 +
             (in->end_time.tv_usec - now.tv_usec) / 1000;
+        if (timeout < 0) {
+            *sret = 0;
+            return 0;
+        }
     }
     /* We don't need a separate copy of the selstate for poll, but use one
      * anyone for consistency with the select wrapper. */