panic: broken type ref

goroutine 25 [running]:
github.com/google/syzkaller/prog.ArgCommon.Type(...)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:39
github.com/google/syzkaller/prog.(*ConstArg).Size(0xc0020afe60, 0xc0020afe60)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:59 +0xed
github.com/google/syzkaller/prog.foreachArgImpl(0x9b2c80, 0xc001f758a0, 0xc0020e27c0, 0xc0012a9320)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/analysis.go:142 +0x2ba
github.com/google/syzkaller/prog.foreachArgImpl(0x9b2d40, 0xc001f757c0, 0xc0020e27c0, 0xc0012a9320)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/analysis.go:159 +0x62d
github.com/google/syzkaller/prog.foreachArgImpl(0x9b2cc0, 0xc0020d9b30, 0xc0020e27c0, 0xc0012a9320)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/analysis.go:156 +0x5e5
github.com/google/syzkaller/prog.ForeachArg(0xc0020e2300, 0xc0012a9320)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/analysis.go:122 +0xdd
github.com/google/syzkaller/prog.getCompatibleResources(0xc0020e2200, 0x900149, 0xb, 0xc002a26ae0, 0x0, 0x0, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:892 +0xb9
github.com/google/syzkaller/prog.(*randGen).resourceCentric(0xc002a26ae0, 0xc0028addb0, 0xcac6a0, 0x0, 0x0, 0x0, 0xc002a83570, 0xc00015d528, 0x792d89)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:840 +0xfe
github.com/google/syzkaller/prog.(*ResourceType).generate(0xcac6a0, 0xc002a26ae0, 0xc0028addb0, 0x0, 0x9b2c00, 0xc002a83570, 0x0, 0x0, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:669 +0x27c
github.com/google/syzkaller/prog.(*randGen).generateArgImpl(0xc002a26ae0, 0xc0028addb0, 0x9b8fa0, 0xcac6a0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:658 +0x450
github.com/google/syzkaller/prog.(*randGen).generateArg(...)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:608
github.com/google/syzkaller/prog.(*randGen).generateArgs(0xc002a26ae0, 0xc0028addb0, 0xd402e0, 0xc, 0xc, 0xaaaaaaaaaaaaaa00, 0x38, 0x8, 0x2, 0x2, ...)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:596 +0x116
github.com/google/syzkaller/prog.(*StructType).generate(0xcb6c60, 0xc002a26ae0, 0xc0028addb0, 0x0, 0xd79600, 0xc002a26a28, 0x9b9060, 0x20, 0x20)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:780 +0x7c
github.com/google/syzkaller/prog.(*randGen).generateArgImpl(0xc002a26ae0, 0xc0028addb0, 0x9b9060, 0xcb6c60, 0x420000, 0x0, 0x0, 0x0, 0x0, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:658 +0x450
github.com/google/syzkaller/prog.(*randGen).generateArg(...)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:608
github.com/google/syzkaller/prog.(*randGen).generateArgs(0xc002a26ae0, 0xc0028addb0, 0xcb6e20, 0x2, 0x2, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:596 +0x116
github.com/google/syzkaller/prog.(*StructType).generate(0xcb6de0, 0xc002a26ae0, 0xc0028addb0, 0x0, 0xd79600, 0x0, 0x0, 0x0, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:780 +0x7c
github.com/google/syzkaller/prog.(*randGen).generateArgImpl(0xc002a26ae0, 0xc0028addb0, 0x9b9060, 0xcb6de0, 0xd70000, 0x0, 0x0, 0x0, 0x0, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:658 +0x450
github.com/google/syzkaller/prog.(*randGen).generateArg(...)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:608
github.com/google/syzkaller/prog.(*UnionType).mutate(0xcafaa0, 0xc002a26ae0, 0xc0028addb0, 0x9b2d40, 0xc002a269c0, 0xc002a26908, 0xcb5fa0, 0x2, 0x2, 0xc002bc1e60, ...)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:457 +0x178
github.com/google/syzkaller/prog.(*Target).mutateArg(0xc0000d36c0, 0xc002a26ae0, 0xc0028addb0, 0x9b2d40, 0xc002a269c0, 0xc002a26908, 0xcb5fa0, 0x2, 0x2, 0xc002bc1e60, ...)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:229 +0xe3
github.com/google/syzkaller/prog.(*mutator).mutateArg(0xc0012a9ec0, 0xa)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:182 +0x288
github.com/google/syzkaller/prog.(*Prog).Mutate(0xc00129d700, 0x9ac300, 0xc0027f95f0, 0x14, 0xc002781dc0, 0xc002abe000, 0x274e, 0x3000)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:47 +0x32c
main.(*Proc).loop(0xc002781e00)
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/proc.go:95 +0x434
created by main.main
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/fuzzer.go:260 +0x1188