slirp: Check qemu_socket() return value in udp_listen()

Check the return value from qemu_socket() rather than trying to
pass it to bind() as an fd argument even if it's negative.
This wouldn't have caused any negative consequences, because
it won't be a valid fd number and the bind call will fail;
but Coverity complains (CID 1005723).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/udp.c b/udp.c
index fde0585..e46b1c8 100644
--- a/udp.c
+++ b/udp.c
@@ -326,6 +326,10 @@ struct socket *udp_listen(Slirp *slirp, uint32_t haddr, u_int hport,
         return NULL;
     }
     so->s = qemu_socket(AF_INET, SOCK_DGRAM, 0);
+    if (so->s < 0) {
+        sofree(so);
+        return NULL;
+    }
     so->so_expire = curtime + SO_EXPIRE;
     insque(so, &slirp->udb);