Skip to content

cl: guard zero-sized interface deref #1912

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
cpunion wants to merge 2 commits into
base: main
Choose a base branch
from
Draft

cl: guard zero-sized interface deref #1912

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
04edb4a
cl: guard zero-sized interface deref
cpunion May 24, 2026
ed11fca
ci: rerun PR checks
cpunion May 24, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 5 additions & 1 deletion cl/compile.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -95,6 +95,10 @@ func (p *context) isLargeNonPointerValue(t llssa.Type) bool {
return sizes.Sizeof(raw) > maxDirectDerefSize
}

func (p *context) isZeroSizedValue(t llssa.Type) bool {
return p.prog.SizeOf(t) == 0
}

func dbgGoSSADump(f interface {
WriteTo(io.Writer) (int64, error)
}) {
Expand Down Expand Up @@ -988,7 +992,7 @@ func (p *context) compileInstrOrValue(b llssa.Builder, iv instrOrValue, asValue
t := p.type_(v.Type(), llssa.InGo)
if unop, ok := v.X.(*ssa.UnOp); ok && unop.Op == token.MUL {
if vt := p.type_(unop.Type(), llssa.InGo); vt.RawType() != nil {
if p.isLargeNonPointerValue(vt) {
if p.isLargeNonPointerValue(vt) || p.isZeroSizedValue(vt) {
if ptr := p.compileValue(b, unop.X); ptr.Type != nil {
p.assertNilDerefBase(b, unop.X)
ret = b.MakeInterfaceFromPtr(t, ptr)
Expand Down
9 changes: 9 additions & 0 deletions test/go/nil_pointer_interface_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,8 @@ import "testing"

type nilPointerInterfaceLarge [1 << 21]byte

type nilPointerInterfaceZero struct{}

type nilPointerInterfaceLargeStruct struct {
data [1 << 21]byte
}
Expand Down Expand Up @@ -32,6 +34,13 @@ func TestNilPointerLargeArrayToInterfacePanics(t *testing.T) {
})
}

func TestNilPointerZeroSizedValueToInterfacePanics(t *testing.T) {
expectNilPointerInterfacePanic(t, func() {
var p *nilPointerInterfaceZero
nilPointerInterfaceSink = *p
})
}

func TestNilPointerLargeStructToInterfacePanics(t *testing.T) {
expectNilPointerInterfacePanic(t, func() {
var p *nilPointerInterfaceLargeStruct
Expand Down
8 changes: 0 additions & 8 deletions test/goroot/xfail.yaml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3614,10 +3614,6 @@ xfails:
directive: run
case: fixedbugs/issue15175.go
reason: current main goroot run failure on darwin/arm64
- platform: darwin/arm64
directive: run
case: fixedbugs/issue19246.go
reason: current main goroot run failure on darwin/arm64
- platform: darwin/arm64
directive: run
case: fixedbugs/issue23017.go
Expand Down Expand Up @@ -3812,10 +3808,6 @@ xfails:
directive: run
case: fixedbugs/issue15175.go
reason: current main goroot run failure on linux/amd64
- platform: linux/amd64
directive: run
case: fixedbugs/issue19246.go
reason: current main goroot run failure on linux/amd64
- platform: linux/amd64
directive: run
case: fixedbugs/issue23017.go
Expand Down
Loading