@ -115,6 +115,7 @@ func (ss *sshSession) newIncubatorCommand(logf logger.Logf) (cmd *exec.Cmd, err
"--gid=" + lu . Gid ,
"--groups=" + groups ,
"--local-user=" + lu . Username ,
"--home-dir=" + lu . HomeDir ,
"--remote-user=" + remoteUser ,
"--remote-ip=" + ci . src . Addr ( ) . String ( ) ,
"--has-tty=false" , // updated in-place by startWithPTY
@ -179,6 +180,7 @@ type incubatorArgs struct {
gid int
gids [ ] int
localUser string
homeDir string
remoteUser string
remoteIP string
ttyName string
@ -201,6 +203,7 @@ func parseIncubatorArgs(args []string) (incubatorArgs, error) {
flags . IntVar ( & ia . gid , "gid" , 0 , "the gid of local-user" )
flags . StringVar ( & groups , "groups" , "" , "comma-separated list of gids of local-user" )
flags . StringVar ( & ia . localUser , "local-user" , "" , "the user to run as" )
flags . StringVar ( & ia . homeDir , "home-dir" , "/" , "the user's home directory" )
flags . StringVar ( & ia . remoteUser , "remote-user" , "" , "the remote user/tags" )
flags . StringVar ( & ia . remoteIP , "remote-ip" , "" , "the remote Tailscale IP" )
flags . StringVar ( & ia . ttyName , "tty-name" , "" , "the tty name (pts/3)" )
@ -565,7 +568,7 @@ const (
// dropPrivileges calls doDropPrivileges with uid, gid, and gids from the given
// incubatorArgs.
func dropPrivileges ( dlogf logger . Logf , ia incubatorArgs ) error {
return doDropPrivileges ( dlogf , ia . uid , ia . gid , ia . gids )
return doDropPrivileges ( dlogf , ia . uid , ia . gid , ia . gids , ia . homeDir )
}
// doDropPrivileges contains all the logic for dropping privileges to a different
@ -578,7 +581,7 @@ func dropPrivileges(dlogf logger.Logf, ia incubatorArgs) error {
// be done by running:
//
// go test -c ./ssh/tailssh/ && sudo ./tailssh.test -test.v -test.run TestDoDropPrivileges
func doDropPrivileges ( dlogf logger . Logf , wantUid , wantGid int , supplementaryGroups [ ] int ) error {
func doDropPrivileges ( dlogf logger . Logf , wantUid , wantGid int , supplementaryGroups [ ] int , homeDir string ) error {
dlogf ( "dropping privileges" )
fatalf := func ( format string , args ... any ) {
dlogf ( "[unexpected] error dropping privileges: " + format , args ... )
@ -664,6 +667,13 @@ func doDropPrivileges(dlogf logger.Logf, wantUid, wantGid int, supplementaryGrou
// TODO(andrew-d): assert that our supplementary groups are correct
}
// Prefer to run in user's homedir if possible. We ignore a failure to Chdir,
// which just leaves us at "/" where we launched in the first place.
dlogf ( "attempting to chdir to user's home directory %q" , homeDir )
if err := os . Chdir ( homeDir ) ; err != nil {
dlogf ( "failed to chdir to user's home directory %q, continuing in current directory" , homeDir )
}
return nil
}
@ -680,16 +690,7 @@ func (ss *sshSession) launchProcess() error {
}
cmd := ss . cmd
homeDir := ss . conn . localUser . HomeDir
if _ , err := os . Stat ( homeDir ) ; err == nil {
cmd . Dir = homeDir
} else if os . IsNotExist ( err ) {
// If the home directory doesn't exist, we can't chdir to it.
// Instead, we'll chdir to the root directory.
cmd . Dir = "/"
} else {
return err
}
cmd . Dir = "/"
cmd . Env = envForUser ( ss . conn . localUser )
for _ , kv := range ss . Environ ( ) {
if acceptEnvPair ( kv ) {