panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x28 pc=0x7b07f9]

goroutine 23 [running]:
github.com/google/syzkaller/sys/openbsd.(*arch).SanitizeCall(0xc00000d640, 0xc001aefac0)
	/syzkaller/gopath/src/github.com/google/syzkaller/sys/openbsd/init.go:75 +0x29
github.com/google/syzkaller/prog.(*Prog).Mutate(0xc001aef180, 0x9a1f20, 0xc0029a86c0, 0x1e, 0xc002977300, 0xc002cfc000, 0x1e5c, 0x2400)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:50 +0x331
main.(*Proc).loop(0xc002977340)
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/proc.go:99 +0x434
created by main.main
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/fuzzer.go:259 +0x114c