r0 = socket$nl_route(0x10, 0x3, 0x0)
r1 = fcntl$dupfd(r0, 0x0, r0)
sendmsg$nl_route_sched(r0, &(0x7f0000000300)={0x0, 0x0, &(0x7f00000002c0)={&(0x7f0000000240)=@getchain={0x24, 0x66, 0x1}, 0x24}}, 0x0)
recvfrom$unix(r1, 0x0, 0x0, 0x0, &(0x7f0000000480)=@abs, 0x6e)
panic: replaceArg: group fields don't match: 1/0

goroutine 30 [running]:
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc008dab5e0?}, {0xe56770?, 0xc008dab740?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:377 +0x425
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc008dab5c0?}, {0xe56770?, 0xc008dab720?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc008dab5a0?}, {0xe56770?, 0xc008dab700?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc008dab580?}, {0xe56770?, 0xc008dab6e0?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc008dab560?}, {0xe56770?, 0xc008dab6c0?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.(*StructType).mutate(0x16d44a0, 0xc008dab680, 0xc007215090, {0xe56770, 0xc008dab540?}, {0xc007215048, {0x1db72e0, 0x4, 0x4}, 0xc008162a50, ...})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:490 +0x185
github.com/google/syzkaller/prog.(*Target).mutateArg(0x418408?, 0xc004b47160?, 0x1389760?, {0xe56770, 0xc008dab540}, {0xc007215048, {0x1db72e0, 0x4, 0x4}, 0xc008162a50, ...}, ...)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:245 +0xe2
github.com/google/syzkaller/prog.(*mutator).mutateArg(0xc001657d60)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:196 +0x245
github.com/google/syzkaller/prog.(*Prog).Mutate(0xc0081089c0, {0xe52aa8?, 0xc0059e6a50}, 0x1e, 0xc005ac6340, 0xc00007e7b0, {0xc005164000, 0x2763, 0x3000})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:51 +0x2ba
main.(*Proc).smashInput(0xc005ac6580, 0xc004f27620)
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/proc.go:221 +0x165
main.(*Proc).loop(0xc005ac6580)
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/proc.go:78 +0xf2
created by main.main in goroutine 1
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/fuzzer.go:336 +0x1665