panic: sandbox escaping file name "../file0"

goroutine 16 [running]:
github.com/google/syzkaller/prog.(*randGen).filename(0xc0006dc220, 0xc000852a00, 0xbf7440, 0xc0006c5460, 0x4f0c53)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:161 +0x2ac
github.com/google/syzkaller/prog.(*BufferType).generate(0xbf7440, 0xc0006dc220, 0xc000852a00, 0x8fa9a0, 0xc0006dd3a0, 0x0, 0x0, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:646 +0x4fc
github.com/google/syzkaller/prog.(*randGen).generateArgImpl(0xc0006dc220, 0xc000852a00, 0x8fd600, 0xbf7440, 0xc0006c5600, 0x0, 0x0, 0x0, 0x0, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:581 +0x1b6
github.com/google/syzkaller/prog.(*randGen).generateArg(0xc0006dc220, 0xc000852a00, 0x8fd600, 0xbf7440, 0x0, 0x0, 0x0, 0x0, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:530 +0x52
github.com/google/syzkaller/prog.(*randGen).generateArgs(0xc0006dc220, 0xc000852a00, 0xbc72e0, 0x2, 0x2, 0x101, 0xc00086d8c0, 0xc0006c5830, 0x742bb6, 0x885e27, ...)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:518 +0x11d
github.com/google/syzkaller/prog.(*StructType).generate(0xbca4e0, 0xc0006dc220, 0xc000852a00, 0x10, 0xc7e300, 0xe2, 0xc0006c5880, 0x4f0c53)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:713 +0x76
github.com/google/syzkaller/prog.(*randGen).generateArgImpl(0xc0006dc220, 0xc000852a00, 0x8fdba0, 0xbca4e0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:581 +0x1b6
github.com/google/syzkaller/prog.(*randGen).generateArg(0xc0006dc220, 0xc000852a00, 0x8fdba0, 0xbca4e0, 0x203000, 0x7432d6, 0x882599, 0xb, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:530 +0x52
github.com/google/syzkaller/prog.(*UnionType).generate(0xbc9520, 0xc0006dc220, 0xc000852a00, 0xb, 0xc7e300, 0xc0006c59e8, 0x4f0c53, 0xc000746e70)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:720 +0xa3
github.com/google/syzkaller/prog.(*randGen).generateArgImpl(0xc0006dc220, 0xc000852a00, 0x8fdc40, 0xbc9520, 0xc000000000, 0x0, 0x0, 0x0, 0x0, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:581 +0x1b6
github.com/google/syzkaller/prog.(*randGen).generateArg(0xc0006dc220, 0xc000852a00, 0x8fdc40, 0xbc9520, 0x834da0, 0xc000065d40, 0x7437b2, 0x87a299, 0x3)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:530 +0x52
github.com/google/syzkaller/prog.(*PtrType).generate(0xbd4ae0, 0xc0006dc220, 0xc000852a00, 0xb, 0xc000065dc8, 0x0, 0x0, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:729 +0x84
github.com/google/syzkaller/prog.(*randGen).generateArgImpl(0xc0006dc220, 0xc000852a00, 0x8fda60, 0xbd4ae0, 0xc0006c5b00, 0x0, 0x0, 0x0, 0x0, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:581 +0x1b6
github.com/google/syzkaller/prog.(*randGen).generateArg(0xc0006dc220, 0xc000852a00, 0x8fda60, 0xbd4ae0, 0x0, 0x0, 0x0, 0x0, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:530 +0x52
github.com/google/syzkaller/prog.(*randGen).generateArgs(0xc0006dc220, 0xc000852a00, 0xbe3a20, 0x6, 0x6, 0x41b9a8c0c37f0118, 0xc0006c5db0, 0x72beae, 0x7f3580, 0xc000718db0, ...)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:518 +0x11d
github.com/google/syzkaller/prog.(*randGen).generateParticularCall(0xc0006dc220, 0xc000852a00, 0xbdee60, 0xad, 0xc000852a00, 0xc00086d590)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:462 +0xd1
github.com/google/syzkaller/prog.(*randGen).generateCall(0xc0006dc220, 0xc000852a00, 0xc0008522c0, 0xc000852a00, 0xc0006c5e48, 0x7311e7)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:454 +0xa4
github.com/google/syzkaller/prog.(*mutator).insertCall(0xc0006c5ed0, 0x14)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:118 +0xcb
github.com/google/syzkaller/prog.(*Prog).Mutate(0xc0008522c0, 0x8f8660, 0xc000746e70, 0x1e, 0xc000796d40, 0xc0002fa000, 0x974, 0xc00)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:32 +0x299
main.(*Proc).loop(0xc000796d80)
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/proc.go:99 +0x446created by main.main
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/fuzzer.go:236 +0xfe2
C›Ô×