fix: race in wait value

See #46

The issue was that `.TryGet()` can return `ok == true` and
`value == nil` which would crash the whole process.

From `relay.go`, `runToPeer` function:

```go
stream, ok := wv.TryGet()
if !ok {
  // some handling
}

// here we assume that `stream != nil`, but due to the bug
// in waitValue, it's not true

stream.Send(...) // <<<< panic
```

Signed-off-by: Andrey Smirnov <[email protected]>
Co-authored-by: Utku Ozdemir <[email protected]>

Author: smira

.github/workflows/ci.yaml

@@ -1,6 +1,6 @@
 # THIS FILE WAS AUTOMATICALLY GENERATED, PLEASE DO NOT EDIT.
 #
-# Generated on 2025-01-22T18:43:52Z by kres 3075de9.
+# Generated on 2025-06-05T10:30:41Z by kres fc6afbe.
 
 name: default
 concurrency:
@@ -32,7 +32,7 @@ jobs:
     steps:
       - name: gather-system-info
         id: system-info
-        uses: kenchan0130/[email protected].0
+        uses: kenchan0130/[email protected].1
         continue-on-error: true
       - name: print-system-info
         run: |

.golangci.yml

@@ -1,116 +1,32 @@
 # THIS FILE WAS AUTOMATICALLY GENERATED, PLEASE DO NOT EDIT.
 #
-# Generated on 2025-03-07T16:55:05Z by kres ef4356e.
+# Generated on 2025-06-05T10:30:41Z by kres fc6afbe.
+
+version: "2"
 
 # options for analysis running
 run:
-  timeout: 10m
+  modules-download-mode: readonly
   issues-exit-code: 1
   tests: true
-  build-tags: [ ]
-  modules-download-mode: readonly
 
 # output configuration options
 output:
   formats:
-    - format: colored-line-number
+    text:
       path: stdout
-  print-issued-lines: true
-  print-linter-name: true
+      print-issued-lines: true
+      print-linter-name: true
   path-prefix: ""
 
-# all available settings of specific linters
-linters-settings:
-  dogsled:
-    max-blank-identifiers: 2
-  dupl:
-    threshold: 150
-  errcheck:
-    check-type-assertions: true
-    check-blank: true
-  exhaustive:
-    default-signifies-exhaustive: false
-  gci:
-    sections:
-      - standard # Standard section: captures all standard packages.
-      - default # Default section: contains all imports that could not be matched to another section type.
-      - localmodule # Imports from the same module.
-  gocognit:
-    min-complexity: 30
-  nestif:
-    min-complexity: 5
-  goconst:
-    min-len: 3
-    min-occurrences: 3
-  gocritic:
-    disabled-checks: [ ]
-  gocyclo:
-    min-complexity: 20
-  godot:
-    scope: declarations
-  gofmt:
-    simplify: true
-  gomodguard: { }
-  govet:
-    enable-all: true
-  lll:
-    line-length: 200
-    tab-width: 4
-  misspell:
-    locale: US
-    ignore-words: [ ]
-  nakedret:
-    max-func-lines: 30
-  prealloc:
-    simple: true
-    range-loops: true # Report preallocation suggestions on range loops, true by default
-    for-loops: false # Report preallocation suggestions on for loops, false by default
-  nolintlint:
-    allow-unused: false
-    allow-no-explanation: [ ]
-    require-explanation: false
-    require-specific: true
-  rowserrcheck: { }
-  testpackage: { }
-  unparam:
-    check-exported: false
-  unused:
-    local-variables-are-used: false
-  whitespace:
-    multi-if: false   # Enforces newlines (or comments) after every multi-line if statement
-    multi-func: false # Enforces newlines (or comments) after every multi-line function signature
-  wsl:
-    strict-append: true
-    allow-assign-and-call: true
-    allow-multiline-assign: true
-    allow-cuddle-declarations: false
-    allow-trailing-comment: false
-    force-case-trailing-whitespace: 0
-    force-err-cuddling: false
-    allow-separated-leading-comment: false
-  gofumpt:
-    extra-rules: false
-  cyclop:
-    # the maximal code complexity to report
-    max-complexity: 20
-  depguard:
-    rules:
-      prevent_unmaintained_packages:
-        list-mode: lax # allow unless explicitly denied
-        files:
-          - $all
-        deny:
-          - pkg: io/ioutil
-            desc: "replaced by io and os packages since Go 1.16: https://tip.golang.org/doc/go1.16#ioutil"
 
 linters:
-  enable-all: true
-  disable-all: false
-  fast: false
+  default: all
   disable:
     - exhaustruct
     - err113
     - forbidigo
+    - funcorder
     - funlen
     - gochecknoglobals
     - gochecknoinits
@@ -131,19 +47,109 @@ linters:
     - testifylint # complains about our assert recorder and has a number of false positives for assert.Greater(t, thing, 1)
     - protogetter # complains about us using Value field on typed spec, instead of GetValue which has a different signature
     - perfsprint # complains about us using fmt.Sprintf in non-performance critical code, updating just kres took too long
-    - goimports # same as gci
     - musttag # seems to be broken - goes into imported libraries and reports issues there
+    - nolintlint # gives false positives - disable until https://github.com/golangci/golangci-lint/issues/3228 is resolved
+  # all available settings of specific linters
+  settings:
+    cyclop:
+      # the maximal code complexity to report
+      max-complexity: 20
+    dogsled:
+      max-blank-identifiers: 2
+    dupl:
+      threshold: 150
+    errcheck:
+      check-type-assertions: true
+      check-blank: true
+    exhaustive:
+      default-signifies-exhaustive: false
+    gocognit:
+      min-complexity: 30
+    nestif:
+      min-complexity: 5
+    goconst:
+      min-len: 3
+      min-occurrences: 3
+    gocritic:
+      disabled-checks: [ ]
+    gocyclo:
+      min-complexity: 20
+    godot:
+      scope: declarations
+    gomodguard: { }
+    govet:
+      enable-all: true
+    lll:
+      line-length: 200
+      tab-width: 4
+    misspell:
+      locale: US
+    nakedret:
+      max-func-lines: 30
+    prealloc:
+      simple: true
+      range-loops: true # Report preallocation suggestions on range loops, true by default
+      for-loops: false # Report preallocation suggestions on for loops, false by default
+    rowserrcheck: { }
+    testpackage: { }
+    unparam:
+      check-exported: false
+    unused:
+      local-variables-are-used: false
+    whitespace:
+      multi-if: false   # Enforces newlines (or comments) after every multi-line if statement
+      multi-func: false # Enforces newlines (or comments) after every multi-line function signature
+    wsl:
+      strict-append: true
+      allow-assign-and-call: true
+      allow-multiline-assign: true
+      allow-trailing-comment: false
+      force-case-trailing-whitespace: 0
+      allow-separated-leading-comment: false
+      allow-cuddle-declarations: false
+      force-err-cuddling: false
+    depguard:
+      rules:
+        prevent_unmaintained_packages:
+          list-mode: lax # allow unless explicitly denied
+          files:
+            - $all
+          deny:
+            - pkg: io/ioutil
+              desc: "replaced by io and os packages since Go 1.16: https://tip.golang.org/doc/go1.16#ioutil"
 
+  exclusions:
+    generated: lax
+    paths:
+      - third_party$
+      - builtin$
+      - examples$
 issues:
-  exclude: [ ]
-  exclude-rules: [ ]
-  exclude-use-default: false
-  exclude-case-sensitive: false
   max-issues-per-linter: 10
   max-same-issues: 3
-  new: false
   uniq-by-line: true
+  new: false
 
 severity:
-  default-severity: error
-  case-sensitive: false
+  default: error
+formatters:
+  enable:
+    - gci
+    - gofmt
+    - gofumpt
+  settings:
+    gci:
+      sections:
+        - standard
+        - default
+        - localmodule
+    gofmt:
+      simplify: true
+    gofumpt:
+      extra-rules: false
+  exclusions:
+    generated: lax
+    paths:
+      - third_party$
+      - builtin$
+      - examples$

Dockerfile

@@ -1,15 +1,15 @@
-# syntax = docker/dockerfile-upstream:1.14.0-labs
+# syntax = docker/dockerfile-upstream:1.16.0-labs
 
 # THIS FILE WAS AUTOMATICALLY GENERATED, PLEASE DO NOT EDIT.
 #
-# Generated on 2025-03-07T16:55:05Z by kres ef4356e.
+# Generated on 2025-06-05T10:30:41Z by kres fc6afbe.
 
 ARG TOOLCHAIN
 
 # runs markdownlint
-FROM docker.io/oven/bun:1.2.4-alpine AS lint-markdown
+FROM docker.io/oven/bun:1.2.15-alpine AS lint-markdown
 WORKDIR /src
-RUN bun i markdownlint-cli@0.44.0 [email protected]
+RUN bun i markdownlint-cli@0.45.0 [email protected]
 COPY .markdownlint.json .
 COPY ./README.md ./README.md
 RUN bunx markdownlint --ignore "CHANGELOG.md" --ignore "**/node_modules/**" --ignore '**/hack/chglog/**' --rules sentences-per-line .
@@ -37,6 +37,9 @@ ENV GOPATH=/go
 ARG GOIMPORTS_VERSION
 RUN --mount=type=cache,target=/root/.cache/go-build,id=siderolink/root/.cache/go-build --mount=type=cache,target=/go/pkg,id=siderolink/go/pkg go install golang.org/x/tools/cmd/goimports@v${GOIMPORTS_VERSION}
 RUN mv /go/bin/goimports /bin
+ARG GOMOCK_VERSION
+RUN --mount=type=cache,target=/root/.cache/go-build,id=siderolink/root/.cache/go-build --mount=type=cache,target=/go/pkg,id=siderolink/go/pkg go install go.uber.org/mock/mockgen@v${GOMOCK_VERSION}
+RUN mv /go/bin/mockgen /bin
 ARG PROTOBUF_GO_VERSION
 RUN --mount=type=cache,target=/root/.cache/go-build,id=siderolink/root/.cache/go-build --mount=type=cache,target=/go/pkg,id=siderolink/go/pkg go install google.golang.org/protobuf/cmd/protoc-gen-go@v${PROTOBUF_GO_VERSION}
 RUN mv /go/bin/protoc-gen-go /bin
@@ -53,7 +56,7 @@ ARG DEEPCOPY_VERSION
 RUN --mount=type=cache,target=/root/.cache/go-build,id=siderolink/root/.cache/go-build --mount=type=cache,target=/go/pkg,id=siderolink/go/pkg go install github.com/siderolabs/deep-copy@${DEEPCOPY_VERSION} \
 	&& mv /go/bin/deep-copy /bin/deep-copy
 ARG GOLANGCILINT_VERSION
-RUN --mount=type=cache,target=/root/.cache/go-build,id=siderolink/root/.cache/go-build --mount=type=cache,target=/go/pkg,id=siderolink/go/pkg go install github.com/golangci/golangci-lint/cmd/golangci-lint@${GOLANGCILINT_VERSION} \
+RUN --mount=type=cache,target=/root/.cache/go-build,id=siderolink/root/.cache/go-build --mount=type=cache,target=/go/pkg,id=siderolink/go/pkg go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@${GOLANGCILINT_VERSION} \
 	&& mv /go/bin/golangci-lint /bin/golangci-lint
 RUN --mount=type=cache,target=/root/.cache/go-build,id=siderolink/root/.cache/go-build --mount=type=cache,target=/go/pkg,id=siderolink/go/pkg go install golang.org/x/vuln/cmd/govulncheck@latest \
 	&& mv /go/bin/govulncheck /bin/govulncheck
@@ -94,7 +97,6 @@ FROM base AS lint-golangci-lint
 WORKDIR /src
 COPY .golangci.yml .
 ENV GOGC=50
-RUN golangci-lint config verify --config .golangci.yml
 RUN --mount=type=cache,target=/root/.cache/go-build,id=siderolink/root/.cache/go-build --mount=type=cache,target=/root/.cache/golangci-lint,id=siderolink/root/.cache/golangci-lint,sharing=locked --mount=type=cache,target=/go/pkg,id=siderolink/go/pkg golangci-lint run --config .golangci.yml
 
 # runs govulncheck

Makefile

@@ -1,6 +1,6 @@
 # THIS FILE WAS AUTOMATICALLY GENERATED, PLEASE DO NOT EDIT.
 #
-# Generated on 2025-03-07T16:55:05Z by kres ef4356e.
+# Generated on 2025-06-05T10:30:41Z by kres fc6afbe.
 
 # common variables
 
@@ -17,19 +17,21 @@ WITH_RACE ?= false
 REGISTRY ?= ghcr.io
 USERNAME ?= siderolabs
 REGISTRY_AND_USERNAME ?= $(REGISTRY)/$(USERNAME)
-PROTOBUF_GO_VERSION ?= 1.36.5
+PROTOBUF_GO_VERSION ?= 1.36.6
 GRPC_GO_VERSION ?= 1.5.1
 GRPC_GATEWAY_VERSION ?= 2.26.3
 VTPROTOBUF_VERSION ?= 0.6.0
-GOIMPORTS_VERSION ?= 0.30.0
+GOIMPORTS_VERSION ?= 0.33.0
+GOMOCK_VERSION ?= 0.5.2
 DEEPCOPY_VERSION ?= v0.5.6
-GOLANGCILINT_VERSION ?= v1.64.6
-GOFUMPT_VERSION ?= v0.7.0
-GO_VERSION ?= 1.24.1
+GOLANGCILINT_VERSION ?= v2.1.6
+GOFUMPT_VERSION ?= v0.8.0
+GO_VERSION ?= 1.24.3
 GO_BUILDFLAGS ?=
 GO_LDFLAGS ?=
 CGO_ENABLED ?= 0
 GOTOOLCHAIN ?= local
+GOEXPERIMENT ?= synctest
 TESTPKGS ?= ./...
 KRES_IMAGE ?= ghcr.io/siderolabs/kres:latest
 CONFORMANCE_IMAGE ?= ghcr.io/siderolabs/conform:latest
@@ -65,6 +67,7 @@ COMMON_ARGS += --build-arg=GRPC_GO_VERSION="$(GRPC_GO_VERSION)"
 COMMON_ARGS += --build-arg=GRPC_GATEWAY_VERSION="$(GRPC_GATEWAY_VERSION)"
 COMMON_ARGS += --build-arg=VTPROTOBUF_VERSION="$(VTPROTOBUF_VERSION)"
 COMMON_ARGS += --build-arg=GOIMPORTS_VERSION="$(GOIMPORTS_VERSION)"
+COMMON_ARGS += --build-arg=GOMOCK_VERSION="$(GOMOCK_VERSION)"
 COMMON_ARGS += --build-arg=DEEPCOPY_VERSION="$(DEEPCOPY_VERSION)"
 COMMON_ARGS += --build-arg=GOLANGCILINT_VERSION="$(GOLANGCILINT_VERSION)"
 COMMON_ARGS += --build-arg=GOFUMPT_VERSION="$(GOFUMPT_VERSION)"

internal/wait/value.go

@@ -75,6 +75,13 @@ func (wv *Value[T]) TryGet() (T, bool) {
 	select {
 	case <-set:
 		wv.mx.Lock()
+
+		if wv.set == nil {
+			wv.mx.Unlock()
+
+			return *new(T), false
+		}
+
 		value := wv.value
 		wv.mx.Unlock()