x/crypto/acme/autocert/internal/acmetest: data race in `(*CAServer).handle`

[bcmills]

==================
WARNING: DATA RACE
Read at 0x00c000106ee3 by goroutine 440:
  testing.(*common).logDepth()
      /workdir/go/src/testing/testing.go:882 +0x4e7
  testing.(*common).log()
      /workdir/go/src/testing/testing.go:869 +0xa4
  testing.(*common).Logf()
      /workdir/go/src/testing/testing.go:920 +0x6a
  golang.org/x/crypto/acme/autocert/internal/acmetest.(*CAServer).validateChallenge()
      /workdir/gopath/src/golang.org/x/crypto/acme/autocert/internal/acmetest/ca.go:572 +0x3dc
  golang.org/x/crypto/acme/autocert/internal/acmetest.(*CAServer).handle.func4()
      /workdir/gopath/src/golang.org/x/crypto/acme/autocert/internal/acmetest/ca.go:349 +0x64

Previous write at 0x00c000106ee3 by goroutine 7:
  testing.tRunner.func1()
      /workdir/go/src/testing/testing.go:1426 +0x7e4
  runtime.deferreturn()
      /workdir/go/src/runtime/panic.go:436 +0x32
  testing.(*T).Run.func1()
      /workdir/go/src/testing/testing.go:1486 +0x47

Goroutine 440 (running) created at:
  golang.org/x/crypto/acme/autocert/internal/acmetest.(*CAServer).handle()
      /workdir/gopath/src/golang.org/x/crypto/acme/autocert/internal/acmetest/ca.go:349 +0x40bb
  golang.org/x/crypto/acme/autocert/internal/acmetest.(*CAServer).handle-fm()
      <autogenerated>:1 +0x57
  net/http.HandlerFunc.ServeHTTP()
      /workdir/go/src/net/http/server.go:2084 +0x4d
  net/http.serverHandler.ServeHTTP()
      /workdir/go/src/net/http/server.go:2916 +0x8b6
  net/http.(*conn).serve()
      /workdir/go/src/net/http/server.go:1966 +0xbe4
  net/http.(*Server).Serve.func3()
      /workdir/go/src/net/http/server.go:3071 +0x58

Goroutine 7 (finished) created at:
  testing.(*T).Run()
      /workdir/go/src/testing/testing.go:1486 +0x75d
  testing.runTests.func1()
      /workdir/go/src/testing/testing.go:1839 +0x99
  testing.tRunner()
      /workdir/go/src/testing/testing.go:1439 +0x216
  testing.runTests()
      /workdir/go/src/testing/testing.go:1837 +0x7ec
  testing.(*M).Run()
      /workdir/go/src/testing/testing.go:1719 +0xa84
  main.main()
      _testmain.go:81 +0x2e9
==================
FAIL
FAIL	golang.org/x/crypto/acme/autocert	2.821s

greplogs --dashboard -md -l -e 'WARNING: DATA RACE(\n.*)+\(\*CAServer\)\.handle'

2022-04-05T03:54:36-ae2d966-eec47d0/linux-amd64-race

(attn @golang/security)

[bcmills]

This could be relevant to #51080; however, this race was detected on a linux/amd64 builder, which is a first class port. As such, it is a release-blocker via #11811.

[heschi]

ping: this is a release blocker that hasn't been updated in a while.

[rolandshoemaker]

Appears to be due to calling Logf in a goroutine after the test has finished(/failed). I am unable to trigger the race locally, and the log doesn't show the test name, so unsure where exactly this is happening. Probably should be shutting the server down more cleanly at the end of tests regardless, will look into a fix.

[gopherbot]

Change https://go.dev/cl/405548 mentions this issue: acme/autocert/internal/acmetest: don't validate in goroutine