recvmsg(r6, &(0x7f00000033c0)={&(0x7f00000003c0)=@ethernet={0x0, @dev}, 0x80, &(0x7f0000002040)=[{&(0x7f0000000080)=""/49, 0x31}, {&(0x7f0000004200)=""/4112, 0x1010}, {0x0}, {&(0x7f0000000100)=""/102, 0x66}, {&(0x7f00000021c0)=""/4096, 0x1000}], 0x5, &(0x7f0000001f80)=""/178, 0xb2}, 0x120)
panic: replaceArg: group fields don't match: 14/0

goroutine 31 [running]:
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc02c393040?}, {0xe56770?, 0xc02c4a7bc0?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:377 +0x425
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc02c393060?}, {0xe56770?, 0xc02c4a7ae0?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc02c393080?}, {0xe56770?, 0xc02c4a7ac0?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc02c3936e0?}, {0xe56770?, 0xc02c4a7a80?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc02c393700?}, {0xe56770?, 0xc02c4a7a60?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc02c393720?}, {0xe56770?, 0xc02c4a7a40?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc02c393740?}, {0xe56770?, 0xc02c4a7a20?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc02c393760?}, {0xe56770?, 0xc02c4a7a00?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.(*StructType).mutate(0x16d44a0, 0xc02c392660, 0xc02c065f40, {0xe56770, 0xc02c393780?}, {0xc02c065c28, {0x1db72e0, 0x4, 0x4}, 0xc02c3b4810, ...})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:490 +0x185
github.com/google/syzkaller/prog.(*Target).mutateArg(0x0?, 0x15f1400?, 0xc006d2a130?, {0xe56770, 0xc02c393780}, {0xc02c065c28, {0x1db72e0, 0x4, 0x4}, 0xc02c3b4810, ...}, ...)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:245 +0xe2
github.com/google/syzkaller/prog.(*mutator).mutateArg(0xc001601d60)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:196 +0x245
github.com/google/syzkaller/prog.(*Prog).Mutate(0xc02c3a8ec0, {0xe52aa8?, 0xc022f14060}, 0x1e, 0xc0268ec140, 0xc0000a1f80, {0xc01d080000, 0xf649, 0x11000})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:51 +0x2ba
main.(*Proc).smashInput(0xc0268ec240, 0xc02953eda0)
	/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/proc.go:221 +0x165
main.(*Proc).loop(0xc0268ec240)
	/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