Golang x/tools/gopls: growslice crashes while zeroing

#!stacks
"sigpanic" && "memclrNoHeapPointers" && "growslice" && "binary.AppendUvarint" && "typeindex.New-range1"

Issue created by stacks.

This stack kvhPfw was reported by telemetry:

• crash/crash
• runtime.throw:+9,+0x37
• runtime.sigpanic:+16,+0x16f
• runtime.memclrNoHeapPointers:+42,+0x58
• runtime.growslice:+92,+0x4df
• encoding/binary.AppendUvarint:=46,+0x3a3
• honnef.co/go/tools/internal/typesinternal/typeindex.New-range1:+30,+0x25c
• golang.org/x/tools/go/ast/inspector.Cursor.Preorder.func1:+6,+0xbf
• honnef.co/go/tools/internal/typesinternal/typeindex.New:+15,+0x1d3
• honnef.co/go/tools/internal/analysisinternal/typeindex.init.func1:+2,+0x5b
• golang.org/x/tools/gopls/internal/cache.(*action).exec.func6:+31,+0x8b
• golang.org/x/tools/gopls/internal/cache.(*action).exec:+199,+0x883
• golang.org/x/tools/gopls/internal/cache.execActions.func1.1:+2,+0x4f
• sync.(*Once).doSlow:+5,+0xef
• sync.(*Once).Do:=69,+0x7f
• golang.org/x/tools/gopls/internal/cache.execActions.func1:+2,+0x50
• runtime.goexit:+0,+0x3

golang.org/x/tools/gopls@v0.20.0 go1.24.5 darwin/arm64 vscode (1)

Comment From: adonovan

This crash occurs when zeroing memory returned by malloc. That means one of:

(a) gopls has trampled on malloc's data structures; (b) malloc has a bug; or (c) a hardware failure has changed the value of registers or memory.

I wonder whether we're just seeing the normal background radiation of hardware faults. @prattmic

Comment From: gabyhelp

Related Issues

• x/tools/gopls: analysisinternal.ZeroValue crash on (presumably) unsafe.Pointer #70585 (closed)
• x/tools/gopls: nil deref in x/telemetry/internal/counter.(*Counter).add #73890
• x/tools/gopls: "slice bounds out of range" crash in ExtractToNewFile #70553
• x/tools/gopls: automated issue report (crash) #40819 (closed)
• x/tools/gopls: SEGV in HasSuffix (corrupt string) #74348
• x/tools/gopls: CodeActions: "end \< start" panic #74394 (closed)
• x/tools/gopls: crash in append (invalid string data pointer) #73586
• x/tools/gopls: SEGV while clearing memory in newobject #71561
• x/tools/gopls: out of memory (crash) #42889 (closed)
• x/tools/gopls: Inline call: panic in reflect.Value.Set #74653

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