panic: runtime error: index out of range

goroutine 2059238 [running]:
unicode/utf8.EncodeRune(0xc00067560f, 0x1, 0x1, 0xc0000000e8, 0x1)
	GOROOT/src/unicode/utf8/utf8.go:346 +0x29f
gvisor.googlesource.com/gvisor/pkg/sentry/fs/tty.(*outputQueueTransformer).transform(0x23e9c70, 0xc0003ce160, 0xc0003ce1c8, 0xc000e75f90, 0x43, 0x43, 0xc00078c280)
	pkg/sentry/fs/tty/line_discipline.go:325 +0x38a
gvisor.googlesource.com/gvisor/pkg/sentry/fs/tty.(*queue).pushWaitBufLocked(0xc0003ce1c8, 0xc0003ce160, 0xc001446a80)
	pkg/sentry/fs/tty/queue.go:227 +0x193
gvisor.googlesource.com/gvisor/pkg/sentry/fs/tty.(*queue).write(0xc0003ce1c8, 0x12d1200, 0xc001446a80, 0x12d0300, 0xc001b42d80, 0x0, 0x1, 0x20000080, 0x53, 0x100, ...)
	pkg/sentry/fs/tty/queue.go:187 +0x1d3
gvisor.googlesource.com/gvisor/pkg/sentry/fs/tty.(*lineDiscipline).outputQueueWrite(0xc0003ce160, 0x12d1200, 0xc001446a80, 0x12d0300, 0xc001b42d80, 0x0, 0x1, 0x20000080, 0x53, 0x100, ...)
	pkg/sentry/fs/tty/line_discipline.go:240 +0x148
gvisor.googlesource.com/gvisor/pkg/sentry/fs/tty.(*slaveFileOperations).Write(0xc000a54210, 0x12d1200, 0xc001446a80, 0xc001504360, 0x12d0300, 0xc001b42d80, 0x0, 0x1, 0x20000080, 0x53, ...)
	pkg/sentry/fs/tty/slave.go:125 +0x13b
gvisor.googlesource.com/gvisor/pkg/sentry/fs.(*File).Writev(0xc001504360, 0x12d1200, 0xc001446a80, 0x12d0300, 0xc001b42d80, 0x0, 0x1, 0x20000080, 0x53, 0x100, ...)
	pkg/sentry/fs/file.go:314 +0x1fd
gvisor.googlesource.com/gvisor/pkg/sentry/syscalls/linux.writev(0xc001446a80, 0xc001504360, 0x12d0300, 0xc001b42d80, 0x0, 0x1, 0x20000080, 0x53, 0x100, 0x53, ...)
	pkg/sentry/syscalls/linux/sys_write.go:261 +0xe1
DIAGNOSIS:
I0403 11:37:54.016767   56828 x:0] ***************************
I0403 11:37:54.017448   56828 x:0] Args: [/syzkaller/managers/kvm-direct-overlay-host-race/current/image -root /syzkaller/managers/kvm-direct-overlay-host-race/workdir/gvisor_root -watchdog-action=panic -network=none -debug -platform=ptrace -file-access=exclusive -overlay -network=host debug -stacks ci-gvisor-kvm-direct-overlay-host-race-2]
I0403 11:37:54.017526   56828 x:0] Version release-20190304.1-78-gc4caccd54042
I0403 11:37:54.017558   56828 x:0] PID: 56828
I0403 11:37:54.017583   56828 x:0] UID: 0, GID: 0
I0403 11:37:54.017604   56828 x:0] Configuration:
I0403 11:37:54.017615   56828 x:0] 		RootDir: /syzkaller/managers/kvm-direct-overlay-host-race/workdir/gvisor_root
I0403 11:37:54.017635   56828 x:0] 		Platform: ptrace
I0403 11:37:54.017673   56828 x:0] 		FileAccess: exclusive, overlay: true
I0403 11:37:54.017700   56828 x:0] 		Network: host, logging: false
I0403 11:37:54.017728   56828 x:0] 		Strace: false, max size: 1024, syscalls: []
I0403 11:37:54.017754   56828 x:0] ***************************
D0403 11:37:54.017854   56828 x:0] Load container "/syzkaller/managers/kvm-direct-overlay-host-race/workdir/gvisor_root" "ci-gvisor-kvm-direct-overlay-host-race-2"
D0403 11:37:54.036428   56828 x:0] Signal container "ci-gvisor-kvm-direct-overlay-host-race-2": signal 0
D0403 11:37:54.037882   56828 x:0] Signal sandbox "ci-gvisor-kvm-direct-overlay-host-race-2"
D0403 11:37:54.037927   56828 x:0] Connecting to sandbox "ci-gvisor-kvm-direct-overlay-host-race-2"
D0403 11:37:54.039130   56828 x:0] urpc: successfully marshalled 120 bytes.
I0403 11:37:54.609282   56828 x:0] Found sandbox "ci-gvisor-kvm-direct-overlay-host-race-2", PID: 63822
I0403 11:37:54.609344   56828 x:0] Retrieving sandbox stacks
D0403 11:37:54.609370   56828 x:0] Stacks sandbox "ci-gvisor-kvm-direct-overlay-host-race-2"
D0403 11:37:54.609429   56828 x:0] Connecting to sandbox "ci-gvisor-kvm-direct-overlay-host-race-2"
D0403 11:37:54.609581   56828 x:0] urpc: successfully marshalled 36 bytes.
W0403 11:37:54.660766   56828 x:0] FATAL ERROR: retrieving stacks: getting sandbox "ci-gvisor-kvm-direct-overlay-host-race-2" stacks: urpc method "debug.Stacks" failed: connection reset by peer
retrieving stacks: getting sandbox "ci-gvisor-kvm-direct-overlay-host-race-2" stacks: urpc method "debug.Stacks" failed: connection reset by peer