panic: invalid allocation length: 0x0

goroutine 298 [running]:
gvisor.dev/gvisor/pkg/sentry/pgalloc.(*MemoryFile).Allocate(0xc00030c000, 0x0, 0x3, 0x0, 0x0, 0x0, 0x0)
	pkg/sentry/pgalloc/pgalloc.go:389 +0x6a3
gvisor.dev/gvisor/pkg/sentry/fs/tmpfs.(*fileReadWriter).WriteFromBlocks(0xc000562620, 0xc0006da000, 0xffffffffffffffff, 0x0, 0x7, 0x0, 0x0, 0x0)
	pkg/sentry/fs/tmpfs/inode_file.go:522 +0x2d0
gvisor.dev/gvisor/pkg/sentry/usermem.(*BytesIO).CopyInTo(0xc0003d6120, 0xecc0e0, 0xc000637500, 0x0, 0x1, 0x0, 0x7, 0xeae840, 0xc000562620, 0x7e0000, ...)
	pkg/sentry/usermem/bytes_io.go:79 +0xba
gvisor.dev/gvisor/pkg/sentry/usermem.IOSequence.CopyInTo(...)
	pkg/sentry/usermem/usermem.go:553
gvisor.dev/gvisor/pkg/sentry/fs/tmpfs.(*fileInodeOperations).write(0xc000128000, 0xecc0e0, 0xc000637500, 0xec7ca0, 0xc0003d6120, 0x0, 0x1, 0x0, 0x7, 0x0, ...)
	pkg/sentry/fs/tmpfs/inode_file.go:372 +0x222
gvisor.dev/gvisor/pkg/sentry/fs/tmpfs.(*regularFileOperations).Write(0xc000208080, 0xecc0e0, 0xc000637500, 0xc0006b69a0, 0xec7ca0, 0xc0003d6120, 0x0, 0x1, 0x0, 0x7, ...)
	pkg/sentry/fs/tmpfs/file_regular.go:54 +0x90
gvisor.dev/gvisor/pkg/sentry/fs.(*lockedWriter).WriteAt(0xc0006a6ba0, 0xc0006da000, 0x7, 0x1fd0, 0xfffffffffffffffe, 0xc000692000, 0xecc0e0, 0xc000637500)
	pkg/sentry/fs/file.go:589 +0x1eb
gvisor.dev/gvisor/pkg/sentry/fs.(*lockedWriter).Write(0xc0006a6ba0, 0xc0006da000, 0x7, 0x1fd0, 0x30, 0x0, 0x0)
	pkg/sentry/fs/file.go:569 +0xa1
gvisor.dev/gvisor/pkg/sentry/kernel/pipe.(*buffer).ReadToWriter(0xc0006da000, 0xeae680, 0xc0006a6ba0, 0x7, 0x0, 0x7f98d515fcc8, 0x42df5a, 0x7e4d50)
	pkg/sentry/kernel/pipe/buffer.go:96 +0x99
gvisor.dev/gvisor/pkg/sentry/kernel/pipe.(*Pipe).WriteTo.func3(0xc0006da000, 0xffffffffffffffff, 0x0, 0x8)
	pkg/sentry/kernel/pipe/pipe_util.go:74 +0x56
DIAGNOSIS:
I0128 07:15:27.053731   30651 x:0] ***************************
I0128 07:15:27.053745   30651 x:0] Args: [/syzkaller/managers/ptrace-direct-overlay-host/current/image -root /syzkaller/managers/ptrace-direct-overlay-host/workdir/gvisor_root -watchdog-action=panic -network=none -debug -alsologtostderr -platform=ptrace -file-access=shared -network=host debug -stacks --ps ci-gvisor-ptrace-direct-overlay-host-0]
I0128 07:15:27.053772   30651 x:0] Version release-20200115.0-104-g6b14be4246e8
I0128 07:15:27.053777   30651 x:0] PID: 30651
I0128 07:15:27.053791   30651 x:0] UID: 0, GID: 0
I0128 07:15:27.053795   30651 x:0] Configuration:
I0128 07:15:27.053798   30651 x:0] 		RootDir: /syzkaller/managers/ptrace-direct-overlay-host/workdir/gvisor_root
I0128 07:15:27.053806   30651 x:0] 		Platform: ptrace
I0128 07:15:27.053809   30651 x:0] 		FileAccess: shared, overlay: false
I0128 07:15:27.053817   30651 x:0] 		Network: host, logging: false
I0128 07:15:27.053823   30651 x:0] 		Strace: false, max size: 1024, syscalls: []
I0128 07:15:27.053827   30651 x:0] ***************************
D0128 07:15:27.053854   30651 x:0] Load container "/syzkaller/managers/ptrace-direct-overlay-host/workdir/gvisor_root" "ci-gvisor-ptrace-direct-overlay-host-0"
D0128 07:15:27.055684   30651 x:0] Signal container "ci-gvisor-ptrace-direct-overlay-host-0": signal 0
D0128 07:15:27.055705   30651 x:0] Signal sandbox "ci-gvisor-ptrace-direct-overlay-host-0"
D0128 07:15:27.055711   30651 x:0] Connecting to sandbox "ci-gvisor-ptrace-direct-overlay-host-0"
D0128 07:15:27.055826   30651 x:0] urpc: successfully marshalled 118 bytes.
W0128 07:15:27.172694   30651 x:0] FATAL ERROR: container sandbox is not running
container sandbox is not running
W0128 07:15:27.172814   30651 x:0] Failure to execute command, err: 1