Lighttpd

Hello.

Valgrind has discovered a problem:

==14321== Memcheck, a memory error detector
==14321== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==14321== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info
==14321== Command: ./lighttpd -D -f ./running.conf -m ./.libs
==14321== 
==14321== Syscall param socketcall.connect(serv_addr.sun_path) points to unaddressable byte(s)
==14321==    at 0x584C8B4: connect (connect.c:26)
==14321==    by 0x12BB3D: gw_spawn_connection (gw_backend.c:478)
==14321==    by 0x12F6F7: gw_set_defaults_backend (gw_backend.c:1516)
==14321==    by 0x6744830: mod_fastcgi_set_defaults (mod_fastcgi.c:80)
==14321==    by 0x132DE5: plugins_call_set_defaults (plugin.c:384)
==14321==    by 0x113A3F: server_main (server.c:1471)
==14321==    by 0x1124D1: main (server.c:2098)
==14321==  Address 0x5d72f3e is 0 bytes after a block of size 30 alloc'd
==14321==    at 0x4C2FB0F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14321==    by 0x12CCEC: gw_proc_sockaddr_init.isra.22 (gw_backend.c:412)
==14321==    by 0x12F6D2: gw_set_defaults_backend (gw_backend.c:1510)
==14321==    by 0x6744830: mod_fastcgi_set_defaults (mod_fastcgi.c:80)
==14321==    by 0x132DE5: plugins_call_set_defaults (plugin.c:384)
==14321==    by 0x113A3F: server_main (server.c:1471)
==14321==    by 0x1124D1: main (server.c:2098)
==14321== 
==14321== Syscall param socketcall.bind(my_addr.sun_path) points to unaddressable byte(s)
==14321==    at 0x584C877: bind (syscall-template.S:78)
==14321==    by 0x12BC4D: gw_spawn_connection (gw_backend.c:513)
==14321==    by 0x12F6F7: gw_set_defaults_backend (gw_backend.c:1516)
==14321==    by 0x6744830: mod_fastcgi_set_defaults (mod_fastcgi.c:80)
==14321==    by 0x132DE5: plugins_call_set_defaults (plugin.c:384)
==14321==    by 0x113A3F: server_main (server.c:1471)
==14321==    by 0x1124D1: main (server.c:2098)
==14321==  Address 0x5d72f3e is 0 bytes after a block of size 30 alloc'd
==14321==    at 0x4C2FB0F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14321==    by 0x12CCEC: gw_proc_sockaddr_init.isra.22 (gw_backend.c:412)
==14321==    by 0x12F6D2: gw_set_defaults_backend (gw_backend.c:1510)
==14321==    by 0x6744830: mod_fastcgi_set_defaults (mod_fastcgi.c:80)
==14321==    by 0x132DE5: plugins_call_set_defaults (plugin.c:384)
==14321==    by 0x113A3F: server_main (server.c:1471)
==14321==    by 0x1124D1: main (server.c:2098)
==14321== 
^C==14321== 
==14321== HEAP SUMMARY:
==14321==     in use at exit: 1,918 bytes in 7 blocks
==14321==   total heap usage: 1,974 allocs, 1,967 frees, 138,582 bytes allocated
==14321== 
==14321== LEAK SUMMARY:
==14321==    definitely lost: 0 bytes in 0 blocks
==14321==    indirectly lost: 0 bytes in 0 blocks
==14321==      possibly lost: 0 bytes in 0 blocks
==14321==    still reachable: 1,918 bytes in 7 blocks
==14321==         suppressed: 0 bytes in 0 blocks
==14321== Rerun with --leak-check=full to see details of leaked memory
==14321== 
==14321== For counts of detected and suppressed errors, rerun with: -v
==14321== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 0 from 0)

It looks as the reason in calculating the length of the sockaddr_un (sock_addr.c - 1.4.54):

            memcpy(saddr->un.sun_path, str, hostlen);
          #if defined(SUN_LEN)
            *len = SUN_LEN(&saddr->un);
          #else
            /* stevens says: */
            *len = hostlen + sizeof(saddr->un.sun_family);
          #endif

When the sockets library provides a sockaddr_un structure to the application, the sun_len field is set to SUN_LEN(&sa)+1, where sa is the name of the sockaddr_un variable. This length thus includes the null byte which terminates the file name. https://www.ibm.com/support/knowledgecenter/en/SSB27U_7.1.0/com.ibm.zvm.v710.kiml0/sktunix.htm

config file:

server.modules              = (
                "mod_rewrite",
                                "mod_access",
                                "mod_indexfile",
                                "mod_fastcgi",
                                "mod_cgi",
                                "mod_alias",
                                "mod_openssl",
                                "mod_accesslog" 
)

server.document-root        = "/tmp" 

index-file.names            = ( "index.ws" )

mimetype.assign             = (
  ".pdf"          =>      "application/pdf",
  ".sig"          =>      "application/pgp-signature",
  ".spl"          =>      "application/futuresplash",
  ".class"        =>      "application/octet-stream",
  ".ps"           =>      "application/postscript",
  ".torrent"      =>      "application/x-bittorrent",
  ".dvi"          =>      "application/x-dvi",
  ".gz"           =>      "application/x-gzip",
  ".pac"          =>      "application/x-ns-proxy-autoconfig",
  ".swf"          =>      "application/x-shockwave-flash",
  ".tar.gz"       =>      "application/x-tgz",
  ".tgz"          =>      "application/x-tgz",
  ".tar"          =>      "application/x-tar",
  ".zip"          =>      "application/zip",
  ".mp3"          =>      "audio/mpeg",
  ".m3u"          =>      "audio/x-mpegurl",
  ".wma"          =>      "audio/x-ms-wma",
  ".wax"          =>      "audio/x-ms-wax",
  ".ogg"          =>      "application/ogg",
  ".wav"          =>      "audio/x-wav",
  ".gif"          =>      "image/gif",
  ".jar"          =>      "application/x-java-archive",
  ".jpg"          =>      "image/jpeg",
  ".jpeg"         =>      "image/jpeg",
  ".png"          =>      "image/png",
  ".xbm"          =>      "image/x-xbitmap",
  ".xpm"          =>      "image/x-xpixmap",
  ".xwd"          =>      "image/x-xwindowdump",
  ".css"          =>      "text/css",
  ".html"         =>      "text/html",
  ".htm"          =>      "text/html",
  ".js"           =>      "text/javascript",
  ".asc"          =>      "text/plain",
  ".c"            =>      "text/plain",
  ".cpp"          =>      "text/plain",
  ".log"          =>      "text/plain",
  ".conf"         =>      "text/plain",
  ".text"         =>      "text/plain",
  ".txt"          =>      "text/plain",
  ".dtd"          =>      "text/xml",
  ".xml"          =>      "text/xml",
  ".mpeg"         =>      "video/mpeg",
  ".mpg"          =>      "video/mpeg",
  ".mov"          =>      "video/quicktime",
  ".qt"           =>      "video/quicktime",
  ".avi"          =>      "video/x-msvideo",
  ".asf"          =>      "video/x-ms-asf",
  ".asx"          =>      "video/x-ms-asf",
  ".wmv"          =>      "video/x-ms-wmv",
  ".bz2"          =>      "application/x-bzip",
  ".tbz"          =>      "application/x-bzip-compressed-tar",
  ".tar.bz2"      =>      "application/x-bzip-compressed-tar",
  # default mime type
  ""              =>      "application/octet-stream",
 )

accesslog.filename          = "/tmp/access.log" 
server.errorlog             = "/tmp/error.log" 

url.access-deny             = ( "~", ".inc" )

static-file.exclude-extensions = ( ".lua" )

server.pid-file            = "/tmp/lighttpd.pid" 

fastcgi.server = ( ".ws" =>
                    ( "localhost" =>
                        ( "socket" => "/tmp/kepler-fastcgi.socket",
                        "bin-path" => "/usr/bin/wsapi.fcgi",
                            "max-procs" => 1
                        )
                    )
                )

fastcgi.debug = 0