From 08ed4882aaa50c9629a3e8636b699ceff6592ad6 Mon Sep 17 00:00:00 2001 From: "alex.schade" <39062967+aschade92@users.noreply.github.com> Date: Tue, 15 Feb 2022 15:35:03 +0000 Subject: [PATCH] cmd/go/internal/modfetch: avoid leaking a lockedfile.File in case of write errors The go modules download command has a method called hashZip which checks the hash of a zipped directory versus an expected value, and then writes it out to a file. In the event that the write operation is not successful, we do not close the file, leading to it being leaked. This could happen if the user runs out of disk space, causing the underlying OS write command to return an error. Ultimately, this led to a panic in lockfile.OpenFile which was invoked from a finalizer garbage collecting the leaked file. The result was a stack trace that didn't show the call stack from where the write operation actually failed. Fixes #50858 Change-Id: I4a24d2ab13dc903d623bbf8252b37bb9d724b8de GitHub-Last-Rev: 354ef1d29ed9d9bb2d9bfe4b73306c550aab07fd GitHub-Pull-Request: golang/go#51058 Reviewed-on: https://go-review.googlesource.com/c/go/+/383915 Trust: Cherry Mui Reviewed-by: Bryan Mills Run-TryBot: Bryan Mills TryBot-Result: Gopher Robot --- src/cmd/go/internal/modfetch/fetch.go | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/src/cmd/go/internal/modfetch/fetch.go b/src/cmd/go/internal/modfetch/fetch.go index f5423b48ad..21d5f54688 100644 --- a/src/cmd/go/internal/modfetch/fetch.go +++ b/src/cmd/go/internal/modfetch/fetch.go @@ -319,7 +319,7 @@ func downloadZip(ctx context.Context, mod module.Version, zipfile string) (err e // // If the hash does not match go.sum (or the sumdb if enabled), hashZip returns // an error and does not write ziphashfile. -func hashZip(mod module.Version, zipfile, ziphashfile string) error { +func hashZip(mod module.Version, zipfile, ziphashfile string) (err error) { hash, err := dirhash.HashZip(zipfile, dirhash.DefaultHash) if err != nil { return err @@ -331,16 +331,17 @@ func hashZip(mod module.Version, zipfile, ziphashfile string) error { if err != nil { return err } + defer func() { + if closeErr := hf.Close(); err == nil && closeErr != nil { + err = closeErr + } + }() if err := hf.Truncate(int64(len(hash))); err != nil { return err } if _, err := hf.WriteAt([]byte(hash), 0); err != nil { return err } - if err := hf.Close(); err != nil { - return err - } - return nil } -- 2.48.1