ioctl$sock_ipv4_tunnel_SIOCADDTUNNEL(r0, 0x89f1, &(0x7f00000001c0)={'gretap0\x00', &(0x7f0000000140)=ANY=[@ANYBLOB="65720270656e3000000000001b00", @ANYRES32=r2, @ANYBLOB="7800004000000008000000204426005000680000052f9078ac1e01010a010102072b1eac141437ac141439ac1414bbac1414aaac1414bbac141411ffffffffac1e01017f000001e0000002070f4aac1414bbe00000010a0101000000"]})
getsockopt$IPT_SO_GET_INFO(r1, 0x0, 0x40, &(0x7f0000000000)={'raw\x00'}, &(0x7f00000003c0)=0x54)
panic: replaceArg: group fields don't match: 1/0

goroutine 9 [running]:
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc01e6859c0?}, {0xe56770?, 0xc01e685b20?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:377 +0x425
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc01e6859a0?}, {0xe56770?, 0xc01e685b00?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc01e685980?}, {0xe56770?, 0xc01e685ae0?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc01e685960?}, {0xe56770?, 0xc01e685ac0?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc01e685940?}, {0xe56770?, 0xc01e685aa0?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.(*StructType).mutate(0x16d44a0, 0xc01e685a60, 0xc01e669ae0, {0xe56770, 0xc01e685920?}, {0xc01e669a98, {0x1db72e0, 0x4, 0x4}, 0xc01e8129c0, ...})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:490 +0x185
github.com/google/syzkaller/prog.(*Target).mutateArg(0x418408?, 0xc0238032c0?, 0xc0189cbdc8?, {0xe56770, 0xc01e685920}, {0xc01e669a98, {0x1db72e0, 0x4, 0x4}, 0xc01e8129c0, ...}, ...)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:245 +0xe2
github.com/google/syzkaller/prog.(*mutator).mutateArg(0xc0189cbe48)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:196 +0x245
github.com/google/syzkaller/prog.(*Prog).Mutate(0xc025882580, {0xe52aa8?, 0xc02432c7b0}, 0x1e, 0xc022be8000, 0xc000480ea0, {0xc020400000, 0x1002e, 0x11000})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:51 +0x2ba
main.(*Proc).loop(0xc022be8140)
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/proc.go:95 +0x365
created by main.main in goroutine 1
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/fuzzer.go:336 +0x1665