@@ -476,6 +476,12 @@ func (a *agent) init(ctx context.Context) {
476476},
477477SubsystemHandlers :map [string ]ssh.SubsystemHandler {
478478"sftp" :func (session ssh.Session ) {
479+ ctx := session .Context ()
480+
481+ // Typically sftp sessions don't request a TTY, but if they do,
482+ // we must ensure the gliderlabs/ssh CRLF emulation is disabled.
483+ // Otherwise sftp will be broken. This can happen if a user sets
484+ // `RequestTTY force` in their SSH config.
479485session .DisablePTYEmulation ()
480486
481487var opts []sftp.ServerOption
@@ -484,22 +490,33 @@ func (a *agent) init(ctx context.Context) {
484490// https://github.com/coder/coder/issues/3620
485491u ,err := user .Current ()
486492if err != nil {
487- a . logger .Warn (ctx ,"get sftp working directory failed, unable to get current user" ,slog .Error (err ))
493+ sshLogger .Warn (ctx ,"get sftp working directory failed, unable to get current user" ,slog .Error (err ))
488494}else {
489495opts = append (opts ,sftp .WithServerWorkingDirectory (u .HomeDir ))
490496}
491497
492498server ,err := sftp .NewServer (session ,opts ... )
493499if err != nil {
494- a . logger . Debug (session . Context () ,"initialize sftp server" ,slog .Error (err ))
500+ sshLogger . Debug (ctx ,"initialize sftp server" ,slog .Error (err ))
495501return
496502}
497503defer server .Close ()
504+
498505err = server .Serve ()
499506if errors .Is (err ,io .EOF ) {
507+ // Unless we call `session.Exit(0)` here, the client won't
508+ // receive `exit-status` because `(*sftp.Server).Close()`
509+ // calls `Close()` on the underlying connection (session),
510+ // which actually calls `channel.Close()` because it isn't
511+ // wrapped. This causes sftp clients to receive a non-zero
512+ // exit code. Typically sftp clients don't echo this exit
513+ // code but `scp` on macOS does (when using the default
514+ // SFTP backend).
515+ _ = session .Exit (0 )
500516return
501517}
502- a .logger .Debug (session .Context (),"sftp server exited with error" ,slog .Error (err ))
518+ sshLogger .Warn (ctx ,"sftp server closed with error" ,slog .Error (err ))
519+ _ = session .Exit (1 )
503520},
504521},
505522}