write$char_usb(r1, &(0x7f00000001c0)="e89e4c95e5ef5b28d88716920afe5f5192ba64d93cdaf4a4901bda3d9e40a7d95e3a75cbcc7040a2517f5230f4a79056ebaab563d95d727707fe200b0c0b0b6e5e057aae016d9a52a3d43feaca2f863a48745d0686655345e4ff0a0494ad880098aee8c89ccd3aa238d59c3b7c6f8e10c91cd234819c983beaa333bec3d8b838e8542479b1bf852515b874720c5753d894226e115a8fcaa90c509cfdfe273b78929594567113a7a29020f1c0ae299d12e4c4f9afed67da76633855f4c0cf7f2558480243ba", 0xc5)
panic: replaceArg: group fields don't match: 0/1

goroutine 14 [running]:
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc000a518a0?}, {0xe56770?, 0xc000a51c60?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:377 +0x425
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc000a51880?}, {0xe56770?, 0xc000a51c40?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc000a51860?}, {0xe56770?, 0xc000a51be0?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc000a51840?}, {0xe56770?, 0xc000a51bc0?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc000a51800?}, {0xe56770?, 0xc000a51ba0?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc000a517e0?}, {0xe56770?, 0xc000a51b80?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc000a517c0?}, {0xe56770?, 0xc000a51b60?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.replaceArg({0xe56770?, 0xc000a51780?}, {0xe56770?, 0xc000a51b20?})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:382 +0x345
github.com/google/syzkaller/prog.(*StructType).mutate(0x16d44a0, 0xc000a518e0, 0xc00c6d7a90, {0xe56770, 0xc000a51760?}, {0xc00c6d79f8, {0x1db72e0, 0x4, 0x4}, 0xc00c861380, ...})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:490 +0x185
github.com/google/syzkaller/prog.(*Target).mutateArg(0x418408?, 0xc000ba9dc8?, 0xc000d95e30?, {0xe56770, 0xc000a51760}, {0xc00c6d79f8, {0x1db72e0, 0x4, 0x4}, 0xc00c861380, ...}, ...)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:245 +0xe2
github.com/google/syzkaller/prog.(*mutator).mutateArg(0xc000ba9e48)
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:196 +0x245
github.com/google/syzkaller/prog.(*Prog).Mutate(0xc00c934200, {0xe52aa8?, 0xc0011860c0}, 0x1e, 0xc0012e0000, 0xc00007af00, {0xc0013c8000, 0x420, 0x500})
	/syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:51 +0x2ba
main.(*Proc).loop(0xc0012e0140)
	/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