panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x28 pc=0xa00d4a]

goroutine 1 [running]:
main.diffProgInfo(0x0, 0x7f5703143ef0?)
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/fuzzer.go:432 +0x2a
main.(*FuzzerTool).diffMaxSignal(0xb303a0?, 0xc000664b01?)
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/fuzzer.go:442 +0x97
main.(*FuzzerTool).convertExecutionResult(0x2c?, {{0x6de8, {0xc000ab2000, 0x19cdf, 0x19cdf}, 0x0, 0x0, 0x0, 0x1, 0x0}, ...})
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/fuzzer.go:386 +0x46
main.(*FuzzerTool).exchangeDataCall(0xc000542000, 0x1, {0xc000cefa70, 0x1, 0xae8300?})
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/fuzzer.go:345 +0x325
main.(*FuzzerTool).exchangeDataWorker(0xc000542000)
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/fuzzer.go:380 +0x79
main.main()
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/fuzzer.go:273 +0x1449
I0325 19:59:19.377197    4445 main.go:226] Exiting with status: 512