Signed-off-by: Paul Gofman <pgofman(a)codeweavers.com> --- dlls/ws2_32/socket.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/dlls/ws2_32/socket.c b/dlls/ws2_32/socket.c index 816ca828b90..ed2889b3eb0 100644 --- a/dlls/ws2_32/socket.c +++ b/dlls/ws2_32/socket.c @@ -2989,6 +2989,11 @@ int WINAPI setsockopt( SOCKET s, int level, int optname, const char *optval, int return server_setsockopt( s, IOCTL_AFD_WINE_SET_IP_MULTICAST_LOOP, optval, optlen ); case IP_MULTICAST_TTL: + if (!optlen) + { + SetLastError( WSAEFAULT ); + return -1; + } return server_setsockopt( s, IOCTL_AFD_WINE_SET_IP_MULTICAST_TTL, optval, optlen ); case IP_OPTIONS: -- 2.35.1