cmd/go2go: fuzzing triggers various crashes in type checker #39634

thepudds · 2020-06-17T04:13:16Z

What version of Go are you using (`go version`)?

My local go version used for the fuzzing:

$ go version
go version devel +4ba19b0188 Wed Jun 17 00:44:16 2020 +0000 linux/amd64

Does this issue reproduce with the latest release?

Yes with a recent git checkout dev.go2go

What operating system and processor architecture are you using (`go env`)?

linux/amd64

What did you do?

I tried fuzzing the type checker from the dev.go2go branch for a short period of time (roughly around 45 minutes) and was able to generate a variety of crashes. Here are six samples.

I realize this is still early days, and I suspect it is much more useful to have crashes or panics from code that actual humans wrote, but posting these examples of crashes in case there is interest in hardending against more corner cases, or perhaps using some as test cases in the future.

I was running fzgo, which is a prototype of making fuzzing a first class citizen in the go command (#19109).

The engine underneath fzgo is @dvyukov's go-fuzz. I can post the fuzz function later if interested, but it was a cut down and slightly tweaked fuzz function adapted from https://github.com/dvyukov/go-fuzz-corpus/tree/master/gotypes.

These all crash on the current go2goplay.golang.org:

Crash 1: invalid memory address or nil pointer dereference

go/types.(*Checker).instantiate

package main
type nt(type )interface{g}
type ph(type e nt,g(d))s
func(*ph(e,e))h(d)

http://go2goplay.golang.org/p/7Jk4PT9GX3k

Crash 2: invalid memory address or nil pointer dereference

go/types.optype

package main
type Numeric interface{t}
func t(type T Numeric)(s[]T){0(){s[0][0]}}

https://go2goplay.golang.org/p/46EZOUKBLLu

Crash 3: invalid memory address or nil pointer dereference

go/types.IsInterface

package main
type d*interface{d.p}

https://go2goplay.golang.org/p/HChlkK2A_Di

Crash 4: invalid memory address or nil pointer dereference

go/types.(*Interface).Complete

package main
type Numeric interface{t}
func t(type T Numeric)(s[]T){if(0){*s[0]}}

https://go2goplay.golang.org/p/TwoY4k9kR1w

Crash 5: panic: multiplication of zero with infinity

math/big.(*Float).Mul

package main
func X(){7E700000000*0}

https://go2goplay.golang.org/p/avwOXp4HJrC

Crash 6: panic: assertion failed

go/types.(*Checker).shift

package main
func X(){0<<7E6000000000}

https://go2goplay.golang.org/p/pv_BlSJ9v5W

(Side note: it would be nice to be able to issue commands like go test -fuzz=. ./... (#19109) on the stdlib and elsewhere ;-)

The text was updated successfully, but these errors were encountered:

griesemer · 2020-06-17T04:34:23Z

These are all non-urgent, but I agree the tools shouldn't crash. Will get to these eventually. If you find more similar crashes, please add to this issue, rather than creating many more.

Thanks for reporting!

thepudds · 2020-06-17T04:35:40Z

Hi Robert, that makes sense, and will do.

Thanks for your work here!

zeebo · 2020-06-17T18:28:54Z

I've got some more examples of some crashes that I found manually messing around with things, and this issue seemed like an appropriate place to put them.

Crash 7: panic: assertion failed

package main
type foo interface { bar() }
type x(type A) struct{ foo }
func main() { var _ foo = x(int){} }

https://go2goplay.golang.org/p/1VztHp6nDlp

Crash 8: fatal error: stack overflow

package main
type foo(type A) interface { type A }
func bar(type A foo(A))(a A) {}
func main() {}

https://go2goplay.golang.org/p/fX5PYaFHB1Z

Crash 9: internal compiler error: typecheck DCLFIELD

package main
type foo(type A) interface { type foo(A) }
func main() { var _ = new(foo(int)) }

https://go2goplay.golang.org/p/8-gvXzWvuky

This last one isn't necessarily a crash, but I don't know how to categorize it because it seems like some sort of unknown error class.

Crash 10: looping while expanding type

package main
type w(type A) struct{}
func (_ w(A)) Wrap() w(w(A)) { return w(w(A)){} }
func main() { var _ w(struct{}) }

https://go2goplay.golang.org/p/Vfv72Q_yFoS

mdlayher · 2020-06-17T21:18:00Z

EDIT: it looks like this panic occurs when any function doesn't have a body, so for example: https://go2goplay.golang.org/p/Q4yf9FPaydk

package main

func main()

The usage of //go:linkname below triggers it. Apologies if this is a duplicate.

Here's another one discovered by @zeebo while we were discussing gaining access to the runtime's map hasher functions:

Works fine in normal playground: https://play.golang.org/p/WWVqIxtH7b1
Crashes go2go playground: https://go2goplay.golang.org/p/WWVqIxtH7b1

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x10 pc=0x61ad46]

goroutine 1 [running]:
go/go2go.(*translator).translateBlockStmt(0xc00015b9b0, 0x0)
	/usr/local/go-faketime/src/go/go2go/rewrite.go:454 +0x26
go/go2go.(*translator).translateFuncDecl(0xc00015b9b0, 0xc0000c2230)
	/usr/local/go-faketime/src/go/go2go/rewrite.go:448 +0xc5
go/go2go.(*translator).translate(0xc00015b9b0, 0xc0000c2280)
	/usr/local/go-faketime/src/go/go2go/rewrite.go:376 +0x391
go/go2go.rewriteAST(0xc0000b0240, 0xc0000813b0, 0x0, 0x0, 0xc000081d10, 0xc0000c2280, 0x1, 0xc000081360, 0xc000081d10)
	/usr/local/go-faketime/src/go/go2go/rewrite.go:188 +0x109
go/go2go.RewriteBuffer(0xc0000813b0, 0x7ffcd64eedd8, 0x1e, 0xc0000f8000, 0x477, 0x677, 0x0, 0xc000086a20, 0xc0000869f0, 0xc0000869c0, ...)
	/usr/local/go-faketime/src/go/go2go/go2go.go:132 +0x2c5
main.translateFile(0xc0000813b0, 0x7ffcd64eedd8, 0x1e)
	/usr/local/go-faketime/src/cmd/go2go/translate.go:26 +0xa9
main.main()
	/usr/local/go-faketime/src/cmd/go2go/main.go:64 +0x2ea

Go build failed.

thepudds · 2020-06-19T01:58:10Z

Here is another batch of crashes from fuzzing. (For numbering, I am treating the five from @zeebo and @mdlayher above as part of the numbering sequence, and hence am starting with 12 here).

This is still with:

go version devel +4ba19b0188 Wed Jun 17 00:44:16 2020 +0000 linux/amd64

Crash 12: panic: unreachable

go/types.(*Checker).assignment

package main
var u, i [func(u, c) {}(0, len)]c

https://go2goplay.golang.org/p/zZxlD1B7QpN

Crash 13: panic: internal error: final action list grew

go/types.(*Checker).processFinals

package main
type o(type T) func(*o([]T)) interface {
	T
	error
	error
}

https://go2goplay.golang.org/p/fUILIW9WD5E

Crash 14: fatal error: stack overflow

go/types.(*unifier).nify
(nify -> nify -> nify -> ...)

package main
func F(type *T)(func(T) T) { F(func(T) t {}) }

https://go2goplay.golang.org/p/BaXFnTQjzE4

Crash 15: panic: assertion failed

go/types.makeSubstMap

package main
func y() { var a interface{ p() } = G(string){} }
type G(type X) s
func (G) p()

https://go2goplay.golang.org/p/R9gtjp611eP

Crash 16: panic: assertion failed

go/types.(*subster).typ

package main
type Foo(type T) r
func r(type T)() Foo((Foo(T)))

https://go2goplay.golang.org/p/pXrh7-AoAZi

Crash 17: panic: duplicate method c

go/types.(*Interface).Complete

package main
type Y interface{ c() }
type Z interface {
	c() Y
	Y
}
func F(type T Z)(T)

https://go2goplay.golang.org/p/Q9iDpXeF3u-

Crash 18: panic: nil typ

go/types.(*subster).typ

package main
type o(type T) []func(_ o([]_))

https://go2goplay.golang.org/p/cTESh52u3h6

Crash 19: panic: assertion failed

go/types.(*Checker).rawExpr

package main
type Z [][[]Z{}[0][0]]c

https://go2goplay.golang.org/p/p9olLU-mRQG

thepudds · 2020-06-19T02:07:55Z

Sorry, Crash 15 is probably a duplicate of @zeebo's first crash in #39634 (comment), but I will leave it here regardless (including to avoid renumbering 😅)

griesemer · 2020-06-19T05:57:33Z

Of the first batch, crashes 3, 5, and 6 are real. The others (1, 2, 4) don't crash anymore on dev.go2go. 3, 5, and 6 are unrelated to generics and may also crash in the regular type checker (try go vet on them). If so, please file individual bugs against the regular go/types package.

griesemer · 2020-06-19T06:01:23Z

@zeebo Crashes 7, 8, 9, and 10 don't reproduce in dev.go2go with the type checker. I haven't tried the translator.

thepudds · 2020-06-19T12:42:21Z

Hi @griesemer thanks for taking a look at these.

In case it is more convenient for you or otherwise helps, I put the fuzz-induced crashes from this issue into a set of test cases that exercise go/types, and which you can see here in the standard playground:

https://play.golang.org/p/rtBwSht8Urf

4 of the 14 crash in go1.14.4, while the other 10 pass in go1.14.4. Here are the current results from the standard playground:

go1.14.4

--- PASS: TestGoTypesGo2Go (0.00s)
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-1 (0.00s)
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-2 (0.00s)
    --- SKIP: TestGoTypesGo2Go/issue-39634-crash-3 (0.00s)
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-4 (0.00s)
    --- SKIP: TestGoTypesGo2Go/issue-39634-crash-5 (0.00s)
    --- SKIP: TestGoTypesGo2Go/issue-39634-crash-6 (0.00s)
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-12 (0.00s)
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-13 (0.00s)
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-14 (0.00s)
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-15 (0.00s)
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-16 (0.00s)
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-17 (0.00s)
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-18 (0.00s)
    --- SKIP: TestGoTypesGo2Go/issue-39634-crash-19 (0.00s)
PASS

I haven't yet run them on the latest dev.go2go.

Also, running those in the standard Go Playground executes the tests. However, go2goplay.golang.org seems to have a bug or limitation such that it does not recognize and run those as tests (perhaps related to whatever the root cause might be for #39675).

thepudds · 2020-06-19T17:06:45Z

Hi @griesemer here is the state of crash/pass/skip in the latest commit on dev.go2go, using the fuzzing-originated unit tests I had placed in https://play.golang.org/p/rtBwSht8Urf (same playground link as immediately prior comment).

go version devel +6cf535a27b Fri Jun 19 04:37:09 2020 +0000 linux/amd64

dev.go2go (`6cf535a` Fri Jun 19 04:37:09 2020)

    --- PASS: TestGoTypesGo2Go/issue-39634-crash-1 (0.00s)
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-2 (0.00s)
    --- SKIP: TestGoTypesGo2Go/issue-39634-crash-3 (0.00s)
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-4 (0.00s)
    --- SKIP: TestGoTypesGo2Go/issue-39634-crash-5 (0.00s)
    --- SKIP: TestGoTypesGo2Go/issue-39634-crash-6 (0.00s)
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-12 (0.00s)
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-13 (0.00s)
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-14         # fatal error: stack overflow
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-15 (0.00s)
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-16 (0.00s)
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-17 (0.00s)
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-18 (0.00s)
    --- SKIP: TestGoTypesGo2Go/issue-39634-crash-19 (0.00s)

Progress!

Summary

The 5x FAIL tests are still crashing in latest dev.go2go
The 4x SKIP tests also crash in go1.14.4
The 5x that are now PASS in the latest commit might have been fixed by the changes for cmd/go2go: panic if using generic type with badly defined method as an interface #39664, cmd/go2go: segfault in go2go playground #39693, or cmd/go2go: panic if using a method on undefined type #39672.
- (Those issues cover manually created examples from other gophers, and were reported after this issue. From quick skim of commit one-liners, I don't immediately see which one would fix Crash 17, but presumably it was a different manifestation of one of the other fixes, and in any event it's passing now).

edit: sorry, this comment was initially missing crash-14, which still fails with a stack overflow.

tdakkota · 2020-06-20T10:08:37Z

Crash 14 is caused by

go/src/go/types/unify.go

Line 95 in 0a03088

y = expand(y)

y is *types.Basic which have types.Invalid kind, so expand just returns y

and

go/src/go/types/unify.go

Lines 150 to 157 in 0a03088

    
           if tx := u.x.at(i); tx != nil { 
        
           	// If we have inferred a type tx and it matches y, we 
        
           	// are done. u.nify won't do this check, so do it now 
        
           	// to avoid endless recursion. 
        
           	if tx == y { 
        
           		return true 
        
           	} 
        
           	return u.nify(tx, y, p)

recursive call.

Change

go/src/go/types/unify.go

Lines 94 to 95 in 0a03088

    
           x = expand(x) 
        
           y = expand(y)

to

	x = expand(x)
	if basicX, ok := x.(*Basic); ok && basicX.Kind() == Invalid {
		return false
	}

	y = expand(y)
	if basicY, ok := y.(*Basic); ok && basicY.Kind() == Invalid {
		return false
	}

prevents endless recursion

thepudds · 2020-06-20T12:13:44Z

That's great @tdakkota! Thanks for looking at that!

griesemer · 2020-06-20T18:42:52Z

@tdakkota Thanks for analyzing the problem. The correct fix (forthcoming) is a bit more subtle, though. Checking for the invalid type solves this specific case, but is insufficient in general. For instance, this test case will still recurse infinitely:

func F(type T)(func(T) T) { F(func(T) int {}) }

thepudds · 2020-06-21T13:31:51Z

Hi @griesemer, here is a third batch of fuzz-induced crashes (Crash 20 through Crash 27 for this issue).

For now, I am just posting the unit test form in this link to the standard playground:

https://play.golang.org/p/qXP94Ai_vQq

If you are looking at stack overflows, this new batch includes two new variations of stack overflows.

This new batch of Crashes 20-27 does not crash in Go 1.14.4. Here are the results from running these via 'go test' in the latest dev.go2go:

dev.go2go (`0a03088` Sat Jun 20 04:46:40 2020)

    --- PASS: TestGoTypesGo2Go/issue-39634-crash-1 (0.00s)
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-2 (0.00s)
    --- SKIP: TestGoTypesGo2Go/issue-39634-crash-3 (0.00s)
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-4 (0.00s)
    --- SKIP: TestGoTypesGo2Go/issue-39634-crash-5 (0.00s)
    --- SKIP: TestGoTypesGo2Go/issue-39634-crash-6 (0.00s)
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-12 (0.00s)
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-13 (0.00s)
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-14         # fatal error: stack overflow
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-15 (0.00s)
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-16 (0.00s)
    --- PASS: TestGoTypesGo2Go/issue-39634-crash-17 (0.00s)
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-18 (0.00s)
    --- SKIP: TestGoTypesGo2Go/issue-39634-crash-19 (0.00s)
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-20 (0.00s)
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-21 (0.00s)
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-22         # fatal error: stack overflow
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-23         # fatal error: stack overflow
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-24 (0.00s)
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-25 (0.00s)
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-26 (0.00s)
    --- FAIL: TestGoTypesGo2Go/issue-39634-crash-27 (0.00s)

edit: updated playground link with slightly cleaner version of unit tests. (Original link here).

thepudds · 2020-06-21T18:56:22Z

Hi @griesemer, here is the third batch of fuzz-induced crashes again, but now expanded out in markdown.

Crash 20 and Crash 21 might be duplicates at this point. (Previously, Crash 21 used to crash in go/types.(*Interface).Complete, but now it looks like both 20 and 21 crash in go/types.(*Checker).completeInterface). Also, Crash 24 and 25 might be duplicates of each other.

Finally, I am including go2go playground links here, but the reported behavior in this comment is for 0a03088 (and the go2go playground is older than that).

go version devel +0a030888da Sat Jun 20 04:46:40 2020 +0000 linux/amd64

Crash 20: invalid memory address or nil pointer dereference

go/types.(*Checker).completeInterface

package main
type Z interface{ Z }
func F(type t Z)() { F(t{}) }

https://go2goplay.golang.org/p/wAHpBNS7ZPn

Crash 21: invalid memory address or nil pointer dereference

go/types.(*Checker).completeInterface

package main
type Z interface{ Z }
func F(type *T Z)() { (F(Z)) }

https://go2goplay.golang.org/p/H64m4NteTx5

Crash 22: fatal error: stack overflow

go/types.(*instance).expand
(expand -> instantiate -> TypeParam -> Under -> Named -> expand -> ...)

package main
type T(type _ interface{ a() }) int
type A(type P) T(A(int))

https://go2goplay.golang.org/p/CoxvTTa5xP1

Crash 23: fatal error: stack overflow

go/types.Comparable
(Comparable -> Comparable -> Comparable -> ...)

package main
type T1(type P) struct{ f T2(P) }
type T2(type P) T1(int)
func _() {
	var x T1(int)
	x == x
}

https://go2goplay.golang.org/p/75sK6SAI2c6

Crash 24: panic: assertion failed

go/types.(*unifier).nify

package main
type C(type P) P
func (r C(P)) m() { y := C.m() }

https://go2goplay.golang.org/p/kWYVyRvSGDd

Crash 25: panic: assertion failed

go/types.(*unifier).nify

package main
type T1(type A) int
func (t T1(A)) m1() {}
var x T1.m1

https://go2goplay.golang.org/p/m5k0NKSMK26

Crash 26: panic: assertion failed

go/types.isParameterized

package main
type Y = interface{ F(type Z)() }
func F(type Z)() Y { F() }

https://go2goplay.golang.org/p/BWt_Xe6iwsE

Crash 27: panic: interface is incomplete

go/types.(*Interface).assertCompleteness

package main
func e(type T)() interface{ (x) }
func x() { e() }

https://go2goplay.golang.org/p/Uw5dQZz7Q7M

griesemer · 2020-06-21T21:41:00Z

@thepudds Thanks. I will look at these eventually, they are useful to test the corners of the implementation (keep in mind, this is still a prototype, and some pieces are pretty rough and known to be not correct for all cases).

gopherbot · 2020-07-03T22:21:34Z

Change https://golang.org/cl/240901 mentions this issue: [dev.go2go] go/types: don't modify Named.underlying when checking validity

…idity Addresses crash #20 of #39634. Added test, also for some of the other cases that don't crash anymore. Updates #39634. Change-Id: I999e376985a443ac435f64a7c249f891e7b7a6d7 Reviewed-on: https://go-review.googlesource.com/c/go/+/240901 Reviewed-by: Robert Griesemer <gri@golang.org>

gopherbot · 2020-07-03T22:35:30Z

Change https://golang.org/cl/240902 mentions this issue: [dev.go2go] go/types: don't rely on completed interfaces in isParameterized predicate

…erized predicate Also, take type lists into account when computing predicate. Addresses crash #27 of #39634. Updates #39634. Change-Id: Id6e1d0d86ac1cb9d79828a3b5fdfbeba0e6aace0 Reviewed-on: https://go-review.googlesource.com/c/go/+/240902 Reviewed-by: Robert Griesemer <gri@golang.org>

gopherbot · 2020-07-04T04:55:36Z

Change https://golang.org/cl/240903 mentions this issue: [dev.go2go] go/types: make sure arrays, slices always have an element type

… type Addresses crash #19 of #39634. Updates #39634. Change-Id: I42208511a3fc27432891243dcf4799e80432c2c1 Reviewed-on: https://go-review.googlesource.com/c/go/+/240903 Reviewed-by: Robert Griesemer <gri@golang.org>

gopherbot · 2020-07-04T05:12:05Z

Change https://golang.org/cl/240904 mentions this issue: [dev.go2go] go/types: don't crash instantiating arrays/slices that are not fully set up

…pe declarations. Updates golang#39634. Fixes golang#40037.

gopherbot · 2020-07-05T11:35:14Z

Change https://golang.org/cl/241037 mentions this issue: [dev.go2go] go/types: avoid endless recursion in self-recursive newty…

…e not fully set up Addresses crash #18 of #39634. Updates #39634. Change-Id: I4b1a3d81ce9dc2b59ae9af3146d26f79d8c05973 Reviewed-on: https://go-review.googlesource.com/c/go/+/240904 Reviewed-by: Robert Griesemer <gri@golang.org>

gopherbot · 2020-07-06T22:00:36Z

Change https://golang.org/cl/241122 mentions this issue: [dev.go2go] go/types: don't crash instantiating defined types that are not fully set up

…e not fully set up Addresses crash #16 of #39634. Updates #39634. Change-Id: I33063d6e2176586f097d2d1391f490f1775a2202 Reviewed-on: https://go-review.googlesource.com/c/go/+/241122 Reviewed-by: Robert Griesemer <gri@golang.org>

gopherbot · 2020-07-06T22:08:05Z

Change https://golang.org/cl/241123 mentions this issue: [dev.go2go] go/types: add test for crash 15 from issue 39634

This test case doesn't crash anymore. Updates #39634. Change-Id: I29b13762265ef1c16c0298d141fdb6cf2c01f4ee Reviewed-on: https://go-review.googlesource.com/c/go/+/241123 Reviewed-by: Robert Griesemer <gri@golang.org>

gopherbot · 2020-07-30T00:10:44Z

Change https://golang.org/cl/245737 mentions this issue: [dev.go2go] go/types: don't crash in lookup of incomplete interface

Also, update some comments. Updates #39634. Change-Id: I85c63e4b941e2bc04e8b5a59497fc47e5d578b8b Reviewed-on: https://go-review.googlesource.com/c/go/+/245737 Reviewed-by: Robert Griesemer <gri@golang.org>

gopherbot · 2020-07-30T00:27:39Z

Change https://golang.org/cl/245738 mentions this issue: [dev.go2go] go/types: don't crash in assignment due to prior errors

Addresses crash #12 of 39634. Updates #39634. Change-Id: Ie67545d21b6a1e80fcdec1b2eb101b69c25e2952 Reviewed-on: https://go-review.googlesource.com/c/go/+/245738 Reviewed-by: Robert Griesemer <gri@golang.org>

gopherbot · 2020-07-30T00:57:14Z

Change https://golang.org/cl/245739 mentions this issue: [dev.go2go] go/types: generic types in selector expressions must be instantiated

…nstantiated Addresses crash 24 of #39634. Updates #39634. Change-Id: If44e834834a07719e7f727d12cc24ac4af0997e6 Reviewed-on: https://go-review.googlesource.com/c/go/+/245739 Reviewed-by: Robert Griesemer <gri@golang.org>

gopherbot · 2020-07-30T04:00:12Z

Change https://golang.org/cl/245740 mentions this issue: [dev.go2go] go/types: remove incorrect assert and replace with explanatory comment

…atory comment Addresses crash 26 of #39634. Also, added test case for crash 25 which was fixed with https://golang.org/cl/245739. Updates #39634. Change-Id: I19793eb79fce63052ba055cde0b1dafdd9476895 Reviewed-on: https://go-review.googlesource.com/c/go/+/245740 Reviewed-by: Robert Griesemer <gri@golang.org>

gopherbot · 2020-07-30T04:48:22Z

Change https://golang.org/cl/245742 mentions this issue: [dev.go2go] go/types: add testcase for crash 9 of #39634

This test passes type-checking without problems but the generated code causes a cmd/compile error (filed #40486). Updates #39634. Change-Id: If3dd28605f6d8792c6bd5bb032624e9a6140b2c0 Reviewed-on: https://go-review.googlesource.com/c/go/+/245742 Reviewed-by: Robert Griesemer <gri@golang.org>

griesemer self-assigned this Jun 17, 2020

griesemer added this to the Unreleased milestone Jun 17, 2020

griesemer added the NeedsInvestigation Someone must examine and confirm this is a valid issue and not a duplicate of an existing one. label Jun 17, 2020

zeebo mentioned this issue Jun 18, 2020

cmd/go2go: panic if using a method on undefined type #39672

Closed

thepudds mentioned this issue Jun 19, 2020

cmd/go2go: go2goplay does not have feature parity with play.golang.org #39675

Closed

thepudds changed the title ~~cmd/go2go: fuzzing triggers various crashes~~ cmd/go2go: fuzzing triggers various crashes in type checker Jun 21, 2020

thepudds mentioned this issue Jul 4, 2020

cmd/go2go: newtype of constraint causes endless recursion #40037

Closed

This was referenced Jul 4, 2020

cmd/go2go: assertion failed in unifier.nify #40038

Closed

cmd/go2go: embedded generic type panic: receiver type parameter inference failed #39758

Closed

tdakkota added a commit to tdakkota/go that referenced this issue Jul 5, 2020

[dev.go2go] go/types: avoid endless recursion in self-recursive newty…

5b305e1

…pe declarations. Updates golang#39634. Fixes golang#40037.

tdakkota mentioned this issue Jul 5, 2020

[dev.go2go] go/types: avoid endless recursion in self-recursive newty… #40051

Closed

thepudds mentioned this issue Jul 5, 2020

cmd/go2go: unification panic when type switching on uninstantiated type #40057

Closed

griesemer mentioned this issue Jul 30, 2020

cmd/go2go: generated code leads to cmd/compile internal error #40486

Closed

This was referenced Mar 24, 2021

x/tools/gopls: automated issue report (crash) #45183

Closed

x/tools/gopls: crash in type checker with cgo #44397

Closed

thepudds mentioned this issue Oct 17, 2021

cmd/compile: fuzzing triggers various crashes or internal compiler errors on tip #49019

Open

rsc unassigned griesemer Jun 23, 2022

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cmd/go2go: fuzzing triggers various crashes in type checker #39634

cmd/go2go: fuzzing triggers various crashes in type checker #39634

thepudds commented Jun 17, 2020 •

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griesemer commented Jun 17, 2020

thepudds commented Jun 17, 2020

zeebo commented Jun 17, 2020 •

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mdlayher commented Jun 17, 2020 •

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thepudds commented Jun 19, 2020 •

edited

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griesemer commented Jun 19, 2020

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thepudds commented Jun 19, 2020 •

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thepudds commented Jun 19, 2020 •

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thepudds commented Jun 21, 2020 •

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thepudds commented Jun 21, 2020 •

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cmd/go2go: fuzzing triggers various crashes in type checker #39634

cmd/go2go: fuzzing triggers various crashes in type checker #39634

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thepudds commented Jun 17, 2020 • edited

What version of Go are you using (go version)?

Does this issue reproduce with the latest release?

What operating system and processor architecture are you using (go env)?

What did you do?

Crash 1: invalid memory address or nil pointer dereference

Crash 2: invalid memory address or nil pointer dereference

Crash 3: invalid memory address or nil pointer dereference

Crash 4: invalid memory address or nil pointer dereference

Crash 5: panic: multiplication of zero with infinity

Crash 6: panic: assertion failed

griesemer commented Jun 17, 2020

thepudds commented Jun 17, 2020

zeebo commented Jun 17, 2020 • edited

Crash 7: panic: assertion failed

Crash 8: fatal error: stack overflow

Crash 9: internal compiler error: typecheck DCLFIELD

Crash 10: looping while expanding type

mdlayher commented Jun 17, 2020 • edited

thepudds commented Jun 19, 2020 • edited

Crash 12: panic: unreachable

Crash 13: panic: internal error: final action list grew

Crash 14: fatal error: stack overflow

Crash 15: panic: assertion failed

Crash 16: panic: assertion failed

Crash 17: panic: duplicate method c

Crash 18: panic: nil typ

Crash 19: panic: assertion failed

thepudds commented Jun 19, 2020

griesemer commented Jun 19, 2020

griesemer commented Jun 19, 2020

thepudds commented Jun 19, 2020 • edited

go1.14.4

thepudds commented Jun 19, 2020 • edited

dev.go2go (6cf535a Fri Jun 19 04:37:09 2020)

Summary

tdakkota commented Jun 20, 2020

thepudds commented Jun 20, 2020

griesemer commented Jun 20, 2020

thepudds commented Jun 21, 2020 • edited

dev.go2go (0a03088 Sat Jun 20 04:46:40 2020)

thepudds commented Jun 21, 2020 • edited

Crash 20: invalid memory address or nil pointer dereference

Crash 21: invalid memory address or nil pointer dereference

Crash 22: fatal error: stack overflow

Crash 23: fatal error: stack overflow

Crash 24: panic: assertion failed

Crash 25: panic: assertion failed

Crash 26: panic: assertion failed

Crash 27: panic: interface is incomplete

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thepudds commented Jun 17, 2020 •

edited

What version of Go are you using (`go version`)?

What operating system and processor architecture are you using (`go env`)?

zeebo commented Jun 17, 2020 •

edited

mdlayher commented Jun 17, 2020 •

edited

thepudds commented Jun 19, 2020 •

edited

thepudds commented Jun 19, 2020 •

edited

thepudds commented Jun 19, 2020 •

edited

dev.go2go (`6cf535a` Fri Jun 19 04:37:09 2020)

thepudds commented Jun 21, 2020 •

edited

dev.go2go (`0a03088` Sat Jun 20 04:46:40 2020)

thepudds commented Jun 21, 2020 •

edited