Golang maps: segmentation violation in maps.Clone

Go version

go version go1.22.5 darwin/arm64

Output of `go env` in your module/workspace:

GO111MODULE='on'
GOARCH='arm64'
GOBIN=''
GOCACHE='/Users/radu/Library/Caches/go-build'
GOENV='/Users/radu/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMODCACHE='/Users/radu/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='darwin'
GOPATH='/Users/radu/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/Users/radu/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.22.5.darwin-arm64'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/Users/radu/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.22.5.darwin-arm64/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.22.5'
GCCGO='gccgo'
AR='ar'
CC='clang'
CXX='clang++'
CGO_ENABLED='1'
GOMOD='/Users/radu/go/src/github.com/cockroachdb/pebble/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/x0/5yrxw_4s271g705vjscld23c0000gq/T/go-build2422055407=/tmp/go-build -gno-record-gcc-switches -fno-common'

What did you do?

This is a test that adds, removes, and clones a map:

func TestMapClone(t *testing.T) {
    seed := time.Now().UnixNano()
    t.Logf("seed: %d", seed)
    rng := rand.New(rand.NewSource(seed))
    for i := 0; i < 100; i++ {
        keyRange := 1 + rng.Intn(100)
        clone := make(map[string]int)
        m := make(map[string]int)
        for j := 0; j < 10000; j++ {
            switch rng.Intn(10) {
            case 0, 1, 2, 3, 4:
                m[fmt.Sprint(rng.Intn(keyRange))] = j
            case 5, 6, 7, 8:
                delete(m, fmt.Sprint(rng.Intn(keyRange)))
            case 9:
                clone = maps.Clone(m)
            }
            if rng.Intn(100) == 0 {
                // Revert to the last clone.
                m = clone
            }
        }
    }
}

What did you see happen?

Ran it under stress (-exec 'stress -p 10') and got this (after a few thousand runs):

=== RUN   TestMapClone
    mem_fs_test.go:210: seed: 1724860257984210000
unexpected fault address 0x3731373330313337
fatal error: fault
[signal SIGSEGV: segmentation violation code=0x2 addr=0x3731373330313337 pc=0x1005a5108]

goroutine 19 gp=0x14000104fc0 m=0 mp=0x100b594c0 [running]:
runtime.throw({0x10081e604?, 0x1009018c0?})
        /Users/radu/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.22.5.darwin-arm64/src/runtime/panic.go:1023 +0x40 fp=0x14000066cf0 sp=0x14000066cc0 pc=0x1005cd780
runtime.sigpanic()
        /Users/radu/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.22.5.darwin-arm64/src/runtime/signal_unix.go:895 +0x22c fp=0x14000066d50 sp=0x14000066cf0 pc=0x1005e786c
runtime.moveToBmap(0x1008d7900, 0x14000516ff0, 0x14000066e28?, 0x1005a7d40?, 0x3731373330313337)
        /Users/radu/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.22.5.darwin-arm64/src/runtime/map.go:1456 +0x38 fp=0x14000066de0 sp=0x14000066d60 pc=0x1005a5108
runtime.mapclone2(0x1008d7900, 0x14000516d80)
        /Users/radu/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.22.5.darwin-arm64/src/runtime/map.go:1538 +0x428 fp=0x14000066e80 sp=0x14000066de0 pc=0x1005a57e8
maps.clone({0x1008d7900, 0x14000516d80})
        /Users/radu/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.22.5.darwin-arm64/src/runtime/map.go:1448 +0x2c fp=0x14000066ea0 sp=0x14000066e80 pc=0x10060272c
maps.Clone[...](...)
        /Users/radu/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.22.5.darwin-arm64/src/maps/maps.go:46
github.com/cockroachdb/pebble/vfs.TestMapClone(0x14000135040)

What did you expect to see?

No crash.

Comment From: RaduBerinde

Note: this is similar to #62203 but it's a different code path, and this version includes that fix.

Comment From: ianlancetaylor

CC @randall77 @cuiweixie

Comment From: cuiweixie

it seems that it is hard to reproduce this bug.

➜  issue69110 git:(go1.22.5) ✗ go test . -exec 'stress -p 10'
5s: 6139 runs so far, 0 failures, 10 active
10s: 12220 runs so far, 0 failures, 10 active
15s: 17879 runs so far, 0 failures, 10 active
20s: 23313 runs so far, 0 failures, 10 active
25s: 28194 runs so far, 0 failures, 10 active
30s: 32985 runs so far, 0 failures, 10 active
35s: 37649 runs so far, 0 failures, 10 active
40s: 41962 runs so far, 0 failures, 10 active
45s: 46762 runs so far, 0 failures, 10 active
50s: 51536 runs so far, 0 failures, 10 active
55s: 55238 runs so far, 0 failures, 10 active
1m0s: 59627 runs so far, 0 failures, 10 active
1m5s: 64098 runs so far, 0 failures, 10 active
1m10s: 68611 runs so far, 0 failures, 10 active
1m15s: 72942 runs so far, 0 failures, 10 active
1m20s: 77221 runs so far, 0 failures, 10 active
1m25s: 81015 runs so far, 0 failures, 10 active
1m30s: 84453 runs so far, 0 failures, 10 active
1m35s: 87739 runs so far, 0 failures, 10 active
1m40s: 91737 runs so far, 0 failures, 10 active
1m45s: 95797 runs so far, 0 failures, 10 active
1m50s: 99831 runs so far, 0 failures, 10 active
1m55s: 103550 runs so far, 0 failures, 10 active
2m0s: 107480 runs so far, 0 failures, 10 active
2m5s: 110964 runs so far, 0 failures, 10 active
2m10s: 114569 runs so far, 0 failures, 10 active
2m15s: 118407 runs so far, 0 failures, 10 active
2m20s: 122205 runs so far, 0 failures, 10 active
2m25s: 125963 runs so far, 0 failures, 10 active
2m30s: 129655 runs so far, 0 failures, 10 active
2m35s: 133272 runs so far, 0 failures, 10 active
2m40s: 136882 runs so far, 0 failures, 10 active
2m45s: 140471 runs so far, 0 failures, 10 active
2m50s: 143684 runs so far, 0 failures, 10 active
2m55s: 147028 runs so far, 0 failures, 10 active
3m0s: 150530 runs so far, 0 failures, 10 active
3m5s: 153960 runs so far, 0 failures, 9 active
3m10s: 157431 runs so far, 0 failures, 10 active
3m15s: 160817 runs so far, 0 failures, 10 active
3m20s: 164217 runs so far, 0 failures, 10 active
3m25s: 167710 runs so far, 0 failures, 10 active
3m30s: 171181 runs so far, 0 failures, 10 active
3m35s: 174031 runs so far, 0 failures, 10 active
3m40s: 177329 runs so far, 0 failures, 10 active
3m45s: 180505 runs so far, 0 failures, 10 active
3m50s: 183907 runs so far, 0 failures, 10 active
3m55s: 187184 runs so far, 0 failures, 10 active
4m0s: 190556 runs so far, 0 failures, 10 active
4m5s: 193806 runs so far, 0 failures, 10 active
4m10s: 197141 runs so far, 0 failures, 10 active
4m15s: 200501 runs so far, 0 failures, 10 active
4m20s: 203863 runs so far, 0 failures, 9 active
4m25s: 207117 runs so far, 0 failures, 10 active
4m30s: 210477 runs so far, 0 failures, 10 active
4m35s: 213701 runs so far, 0 failures, 10 active
4m40s: 216769 runs so far, 0 failures, 10 active
4m45s: 220049 runs so far, 0 failures, 10 active
4m50s: 223113 runs so far, 0 failures, 10 active
4m55s: 225959 runs so far, 0 failures, 10 active
5m0s: 229179 runs so far, 0 failures, 10 active
5m5s: 232161 runs so far, 0 failures, 10 active
5m10s: 235190 runs so far, 0 failures, 10 active
5m15s: 238283 runs so far, 0 failures, 10 active
5m20s: 241345 runs so far, 0 failures, 10 active
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5m35s: 249858 runs so far, 0 failures, 10 active
5m40s: 252901 runs so far, 0 failures, 10 active
5m45s: 255867 runs so far, 0 failures, 10 active
5m50s: 258893 runs so far, 0 failures, 10 active
5m55s: 261765 runs so far, 0 failures, 10 active
6m0s: 264876 runs so far, 0 failures, 10 active
6m5s: 267895 runs so far, 0 failures, 10 active
6m10s: 270915 runs so far, 0 failures, 10 active
6m15s: 273848 runs so far, 0 failures, 10 active
6m20s: 277000 runs so far, 0 failures, 10 active
6m25s: 279933 runs so far, 0 failures, 10 active
6m30s: 282925 runs so far, 0 failures, 10 active
6m35s: 285627 runs so far, 0 failures, 10 active
6m40s: 288550 runs so far, 0 failures, 10 active
6m45s: 291669 runs so far, 0 failures, 10 active
6m50s: 294740 runs so far, 0 failures, 10 active
6m55s: 297614 runs so far, 0 failures, 10 active
7m0s: 300528 runs so far, 0 failures, 10 active
7m5s: 303461 runs so far, 0 failures, 10 active
7m10s: 306369 runs so far, 0 failures, 10 active
7m15s: 309361 runs so far, 0 failures, 10 active
7m20s: 312464 runs so far, 0 failures, 10 active
7m25s: 315372 runs so far, 0 failures, 10 active
7m30s: 318256 runs so far, 0 failures, 10 active
7m35s: 321166 runs so far, 0 failures, 10 active
7m40s: 323931 runs so far, 0 failures, 10 active
7m45s: 326720 runs so far, 0 failures, 10 active
7m50s: 329500 runs so far, 0 failures, 10 active
7m55s: 331507 runs so far, 0 failures, 10 active
8m0s: 334102 runs so far, 0 failures, 10 active
8m5s: 337109 runs so far, 0 failures, 10 active
8m10s: 339943 runs so far, 0 failures, 10 active
8m15s: 342885 runs so far, 0 failures, 10 active
8m20s: 346065 runs so far, 0 failures, 10 active
8m25s: 348754 runs so far, 0 failures, 6 active
8m30s: 351610 runs so far, 0 failures, 10 active
8m35s: 354357 runs so far, 0 failures, 10 active
8m40s: 357630 runs so far, 0 failures, 10 active
8m45s: 360389 runs so far, 0 failures, 10 active
8m50s: 363106 runs so far, 0 failures, 10 active
8m55s: 365694 runs so far, 0 failures, 10 active
9m0s: 368866 runs so far, 0 failures, 10 active
9m5s: 371351 runs so far, 0 failures, 10 active
9m10s: 374514 runs so far, 0 failures, 10 active
9m15s: 377226 runs so far, 0 failures, 10 active
9m20s: 380173 runs so far, 0 failures, 10 active
9m25s: 382838 runs so far, 0 failures, 10 active
9m30s: 385835 runs so far, 0 failures, 10 active
9m35s: 388291 runs so far, 0 failures, 10 active
9m40s: 391274 runs so far, 0 failures, 10 active
9m45s: 393967 runs so far, 0 failures, 10 active
9m50s: 396820 runs so far, 0 failures, 10 active
9m55s: 399527 runs so far, 0 failures, 10 active
10m0s: 402584 runs so far, 0 failures, 10 active
10m5s: 405278 runs so far, 0 failures, 10 active
10m10s: 407812 runs so far, 0 failures, 10 active
10m15s: 410144 runs so far, 0 failures, 10 active
10m20s: 412101 runs so far, 0 failures, 10 active
10m25s: 414690 runs so far, 0 failures, 10 active
10m30s: 417384 runs so far, 0 failures, 10 active
10m35s: 420005 runs so far, 0 failures, 10 active
10m40s: 422668 runs so far, 0 failures, 10 active
10m45s: 425176 runs so far, 0 failures, 10 active
10m50s: 427715 runs so far, 0 failures, 10 active
10m55s: 430322 runs so far, 0 failures, 10 active
11m0s: 433534 runs so far, 0 failures, 10 active

Comment From: RaduBerinde

@cuiweixie: are you sure it is actually running the test? On my machine (Apple M1), it can only do a couple hundred runs per 5s:

# go test ./vfs -run TestMapClone -exec 'stress -p 10' -v
194 runs so far, 0 failures, over 5s
405 runs so far, 0 failures, over 10s
^C559 runs completed, 0 failures, over 14s

P.S. A friendly request - please don't post long irrelevant backtraces, it makes the issue hard to navigate. E.g. it would have been sufficient to post just 11m0s: 433534 runs so far, 0 failures, 10 active.

Comment From: cuiweixie

Sorry, I changed the number of iterations!
Run Again!

Comment From: RaduBerinde

It took ~7 minutes for it to crash. But I tried again now and it didn't crash in 11 minutes. It might take a long time.

Note that in https://github.com/cockroachdb/pebble/issues/3894 we saw the fault on address 0 (signal SIGSEGV: segmentation violation code=0x80 addr=0x0 pc=0x417278]). Looking at the code, I don't see how that would happen unless the src pointer is corrupted and is near the end range of uint64, leading to overflow when we access.

Comment From: cuiweixie

I run with you code now!
Do not reproduce! Sad!

➜  issue69110 git:(go1.22.5) ✗ go test -v . -run="TestMapClone" -exec "stress -p 10"
5s: 218 runs so far, 0 failures, 10 active
10s: 464 runs so far, 0 failures, 10 active
15s: 688 runs so far, 0 failures, 10 active
20s: 893 runs so far, 0 failures, 10 active
25s: 1113 runs so far, 0 failures, 10 active
30s: 1344 runs so far, 0 failures, 10 active
35s: 1585 runs so far, 0 failures, 10 active
40s: 1829 runs so far, 0 failures, 10 active
45s: 2067 runs so far, 0 failures, 10 active
50s: 2309 runs so far, 0 failures, 10 active
55s: 2551 runs so far, 0 failures, 10 active
1m0s: 2769 runs so far, 0 failures, 10 active
1m5s: 2968 runs so far, 0 failures, 10 active
1m10s: 3176 runs so far, 0 failures, 10 active
1m15s: 3415 runs so far, 0 failures, 10 active
1m20s: 3653 runs so far, 0 failures, 10 active
1m25s: 3892 runs so far, 0 failures, 10 active
1m30s: 4122 runs so far, 0 failures, 10 active
1m35s: 4338 runs so far, 0 failures, 10 active
1m40s: 4555 runs so far, 0 failures, 10 active
1m45s: 4779 runs so far, 0 failures, 10 active
1m50s: 5006 runs so far, 0 failures, 10 active
1m55s: 5216 runs so far, 0 failures, 10 active
2m0s: 5435 runs so far, 0 failures, 10 active
2m5s: 5668 runs so far, 0 failures, 10 active
2m10s: 5899 runs so far, 0 failures, 10 active
2m15s: 6092 runs so far, 0 failures, 10 active
2m20s: 6317 runs so far, 0 failures, 10 active
2m25s: 6553 runs so far, 0 failures, 10 active
2m30s: 6793 runs so far, 0 failures, 10 active
2m35s: 7036 runs so far, 0 failures, 10 active
2m40s: 7253 runs so far, 0 failures, 10 active
2m45s: 7481 runs so far, 0 failures, 10 active
2m50s: 7727 runs so far, 0 failures, 10 active
2m55s: 7972 runs so far, 0 failures, 10 active
3m0s: 8217 runs so far, 0 failures, 10 active
3m5s: 8467 runs so far, 0 failures, 10 active
3m10s: 8711 runs so far, 0 failures, 10 active
3m15s: 8955 runs so far, 0 failures, 10 active
3m20s: 9203 runs so far, 0 failures, 10 active
3m25s: 9448 runs so far, 0 failures, 10 active
3m30s: 9695 runs so far, 0 failures, 10 active
3m35s: 9938 runs so far, 0 failures, 10 active
3m40s: 10184 runs so far, 0 failures, 10 active
3m45s: 10430 runs so far, 0 failures, 10 active
3m50s: 10674 runs so far, 0 failures, 10 active
3m55s: 10923 runs so far, 0 failures, 10 active
4m0s: 11170 runs so far, 0 failures, 10 active
4m5s: 11413 runs so far, 0 failures, 10 active
4m10s: 11616 runs so far, 0 failures, 10 active
4m15s: 11833 runs so far, 0 failures, 10 active
4m20s: 12047 runs so far, 0 failures, 10 active
4m25s: 12243 runs so far, 0 failures, 10 active
4m30s: 12418 runs so far, 0 failures, 10 active
4m35s: 12547 runs so far, 0 failures, 10 active
4m40s: 12712 runs so far, 0 failures, 10 active
4m45s: 12917 runs so far, 0 failures, 10 active
4m50s: 13143 runs so far, 0 failures, 10 active
4m55s: 13388 runs so far, 0 failures, 10 active
5m0s: 13635 runs so far, 0 failures, 10 active
5m5s: 13877 runs so far, 0 failures, 10 active
5m10s: 14091 runs so far, 0 failures, 10 active
5m15s: 14335 runs so far, 0 failures, 10 active
5m20s: 14582 runs so far, 0 failures, 10 active
5m25s: 14829 runs so far, 0 failures, 10 active
5m30s: 15078 runs so far, 0 failures, 10 active
5m35s: 15321 runs so far, 0 failures, 10 active
5m40s: 15566 runs so far, 0 failures, 10 active
5m45s: 15808 runs so far, 0 failures, 10 active
5m50s: 16051 runs so far, 0 failures, 10 active
5m55s: 16296 runs so far, 0 failures, 10 active
6m0s: 16544 runs so far, 0 failures, 10 active
6m5s: 16784 runs so far, 0 failures, 10 active
6m10s: 17029 runs so far, 0 failures, 10 active
6m15s: 17269 runs so far, 0 failures, 10 active
6m20s: 17499 runs so far, 0 failures, 10 active
6m25s: 17744 runs so far, 0 failures, 10 active
6m30s: 17992 runs so far, 0 failures, 10 active
6m35s: 18235 runs so far, 0 failures, 10 active
6m40s: 18482 runs so far, 0 failures, 10 active
6m45s: 18722 runs so far, 0 failures, 10 active
6m50s: 18970 runs so far, 0 failures, 10 active
6m55s: 19217 runs so far, 0 failures, 10 active
7m0s: 19462 runs so far, 0 failures, 10 active
7m5s: 19705 runs so far, 0 failures, 10 active
7m10s: 19930 runs so far, 0 failures, 10 active
7m15s: 20170 runs so far, 0 failures, 10 active
7m20s: 20419 runs so far, 0 failures, 10 active
7m25s: 20664 runs so far, 0 failures, 10 active
7m30s: 20899 runs so far, 0 failures, 10 active
7m35s: 21138 runs so far, 0 failures, 10 active
7m40s: 21382 runs so far, 0 failures, 10 active
7m45s: 21627 runs so far, 0 failures, 10 active
7m50s: 21871 runs so far, 0 failures, 10 active
7m55s: 22116 runs so far, 0 failures, 10 active
8m0s: 22363 runs so far, 0 failures, 10 active
8m5s: 22609 runs so far, 0 failures, 10 active
8m10s: 22857 runs so far, 0 failures, 10 active
8m15s: 23101 runs so far, 0 failures, 10 active
8m20s: 23312 runs so far, 0 failures, 10 active
8m25s: 23560 runs so far, 0 failures, 10 active
8m30s: 23802 runs so far, 0 failures, 10 active
8m35s: 24048 runs so far, 0 failures, 10 active
8m40s: 24290 runs so far, 0 failures, 10 active
8m45s: 24507 runs so far, 0 failures, 10 active
8m50s: 24741 runs so far, 0 failures, 10 active
8m55s: 24988 runs so far, 0 failures, 10 active
9m0s: 25233 runs so far, 0 failures, 10 active
9m5s: 25477 runs so far, 0 failures, 10 active
9m10s: 25722 runs so far, 0 failures, 10 active
9m15s: 25960 runs so far, 0 failures, 10 active
9m20s: 26202 runs so far, 0 failures, 10 active
9m25s: 26430 runs so far, 0 failures, 10 active
9m30s: 26647 runs so far, 0 failures, 10 active
9m35s: 26838 runs so far, 0 failures, 10 active
9m40s: 27073 runs so far, 0 failures, 10 active
9m45s: 27287 runs so far, 0 failures, 10 active
9m50s: 27536 runs so far, 0 failures, 10 active
9m55s: 27777 runs so far, 0 failures, 10 active
10m0s: 28025 runs so far, 0 failures, 10 active
10m5s: 28267 runs so far, 0 failures, 10 active
10m10s: 28479 runs so far, 0 failures, 10 active
10m15s: 28709 runs so far, 0 failures, 10 active
10m20s: 28950 runs so far, 0 failures, 10 active
10m25s: 29193 runs so far, 0 failures, 10 active
10m30s: 29438 runs so far, 0 failures, 10 active
10m35s: 29678 runs so far, 0 failures, 10 active
10m40s: 29921 runs so far, 0 failures, 10 active
10m45s: 30158 runs so far, 0 failures, 10 active
10m50s: 30401 runs so far, 0 failures, 10 active
10m55s: 30645 runs so far, 0 failures, 10 active

Comment From: RaduBerinde

It might take a while, I'd increase the timeout to e.g. 1 hour. I ran it on many different versions on the test until I saw a crash, so it could have been a particularly lucky run.

Comment From: prattmic

cc @golang/runtime

Comment From: gabyhelp

Related Issues and Documentation

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

Comment From: randall77

I can reproduce, albeit rarely (~1 in 100000 runs).

1.22.5: 7h46m40s: 1850954 runs so far, 13 failures (0.00%)

tip: 1h33m35s: 377150 runs so far, 5 failures (0.00%)

I suspect something about same-sized grow. I'll keep looking.

Comment From: randall77

Yes, looks like it is an odd interaction between same-sized growth, regular growth, and cloning. This causes clone to be in a state where the number of source buckets is less than the number of destination buckets. That causes the clone to walk off the end of the source bucket array.

Here's a reproducer:

package main

import (
    "maps"
    "unsafe"
)

func main() {
    for i := 0; i < 100; i++ {
        f()
    }
}

const NB = 4

func f() {
    // Make a map with NB buckets, at max capacity.
    // 6.5 entries/bucket.
    ne := NB * 13 / 2
    m := map[int]int{}
    for i := 0; i < ne; i++ {
        m[i] = i
    }

    // delete/insert a lot, to hopefully get lots of overflow buckets
    // and trigger a same-size grow.
    ssg := false
    for i := ne; i < ne+1000; i++ {
        delete(m, i-ne)
        m[i] = i
        p := *(**hmap)(unsafe.Pointer(&m))
        if p.flags&8 != 0 { // same-sized grow flag
            ssg = true
            break
        }
    }
    if !ssg {
        return
    }

    // Insert 1 more entry, which would ordinarily trigger a growth.
    // We can't grow while growing, so we instead go over our
    // target capacity.
    m[-1] = -1

    // Cloning in this state will make a map with a destination bucket
    // array twice the size of the source.
    _ = maps.Clone(m)
}

type hmap struct {
    count int
    flags uint8
}

Comment From: gopherbot

Change https://go.dev/cl/609757 mentions this issue: runtime: size maps.Clone destination bucket array safely

Comment From: randall77

@gopherbot Please open backport issues. This is a rare memory corruption bug in maps.Clone.

Comment From: gopherbot

Backport issue(s) opened: #69155 (for 1.22), #69156 (for 1.23).

Remember to create the cherry-pick CL(s) as soon as the patch is submitted to master, according to https://go.dev/wiki/MinorReleases.

Golang maps: segmentation violation in maps.Clone

Go version

Output of go env in your module/workspace:

What did you do?

What did you see happen?

What did you expect to see?

Output of `go env` in your module/workspace: