panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x5f155b]

goroutine 15 [running]:
github.com/google/syzkaller/prog.(*GroupArg).Type(0x0, 0x0, 0x0)
	<autogenerated>:1 +0x2b
github.com/google/syzkaller/prog.calcChecksumsCall.func1(0xd13d00, 0x0, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/checksum.go:34 +0x47
github.com/google/syzkaller/prog.foreachArgImpl(0xd13d00, 0xc0000843a0, 0xc009eb1340, 0xc000331848)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/analysis.go:129 +0x119
github.com/google/syzkaller/prog.foreachArgImpl(0xd13d40, 0xc0003272f0, 0xc009eb1340, 0xc002ff2848)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/analysis.go:156 +0x656
github.com/google/syzkaller/prog.ForeachArg(0xc000152380, 0xc000331848)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/analysis.go:122 +0xdd
github.com/google/syzkaller/prog.calcChecksumsCall(0xc000152380, 0xc000152340, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/checksum.go:33 +0xbe
github.com/google/syzkaller/prog.(*Prog).SerializeForExec(0xc000152200, 0x82ae00000, 0x400000, 0x400000, 0xc009a08140, 0x0, 0xc009dfae58)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/encodingexec.go:75 +0x14c
github.com/google/syzkaller/pkg/ipc.(*Env).Exec(0xc000292990, 0xc0000226b0, 0xc000152200, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/pkg/ipc/ipc.go:255 +0x62
main.(*Proc).executeRaw(0xc009ce20c0, 0xc0000226b0, 0xc000152200, 0x2, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/proc.go:290 +0x214
main.(*Proc).execute(0xc009ce20c0, 0xc0000226b0, 0xc000152200, 0x7, 0x2, 0x0)
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/proc.go:249 +0x6a
main.(*Proc).loop(0xc009ce20c0)
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/proc.go:76 +0x143
created by main.main
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/fuzzer.go:289 +0x1481


FreeBSD/amd64 (ci-freebsd-main-2.c.syzkaller.internal) (ttyu0)

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