panic: invalid allocation length: 0x0

goroutine 20309 [running]:
gvisor.googlesource.com/gvisor/pkg/sentry/platform/filemem.(*FileMem).Allocate(0xc4202c6000, 0x0, 0x3, 0x0, 0x0, 0x0, 0x0)
	pkg/sentry/platform/filemem/filemem.go:232 +0x765
gvisor.googlesource.com/gvisor/pkg/sentry/fs/tmpfs.(*fileReadWriter).WriteFromBlocks(0xc420732000, 0x7ff953001500, 0xffffffffffffffff, 0x0, 0xd3, 0x0, 0x0, 0x0)
	pkg/sentry/fs/tmpfs/inode_file.go:411 +0x461
gvisor.googlesource.com/gvisor/pkg/sentry/safemem.(Writer).WriteFromBlocks-fm(0x7ff953001500, 0xffffffffffffffff, 0x0, 0xd3, 0x200025d3, 0x7ff953001500, 0xffffffffffffffff)
	pkg/sentry/mm/io.go:309 +0x76
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).withInternalMappings(0xc420f50000, 0x10d3f40, 0xc4206ea000, 0x20002500, 0x200025d3, 0x1, 0xc4209cbb68, 0xc4209cb968, 0x47b965, 0x47ed19)
	pkg/sentry/mm/io.go:464 +0x88f
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).withVecInternalMappings(0xc420f50000, 0x10d3f40, 0xc4206ea000, 0x0, 0x1, 0x20002500, 0xd3, 0x1, 0xc4209cbb68, 0x0, ...)
	pkg/sentry/mm/io.go:533 +0x974
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).CopyInTo(0xc420f50000, 0x10d3f40, 0xc4206ea000, 0x0, 0x1, 0x20002500, 0xd3, 0x10c4a60, 0xc420732000, 0x153ca02e79f10000, ...)
	pkg/sentry/mm/io.go:309 +0x211
gvisor.googlesource.com/gvisor/pkg/sentry/usermem.IOSequence.CopyInTo(0x10d2620, 0xc420f50000, 0x0, 0x1, 0x20002500, 0xd3, 0x0, 0x10d3f40, 0xc4206ea000, 0x10c4a60, ...)
	pkg/sentry/usermem/usermem.go:528 +0xcf
gvisor.googlesource.com/gvisor/pkg/sentry/fs/tmpfs.(*fileInodeOperations).write(0xc4202f4d80, 0x10d3f40, 0xc4206ea000, 0x10d2620, 0xc420f50000, 0x0, 0x1, 0x20002500, 0xd3, 0x0, ...)
	pkg/sentry/fs/tmpfs/inode_file.go:289 +0x1cb
gvisor.googlesource.com/gvisor/pkg/sentry/fs/tmpfs.(*regularFileOperations).Write(0xc420ff8008, 0x10d3f40, 0xc4206ea000, 0xc420e98000, 0x10d2620, 0xc420f50000, 0x0, 0x1, 0x20002500, 0xd3, ...)
	pkg/sentry/fs/tmpfs/file_regular.go:50 +0xb9
gvisor.googlesource.com/gvisor/pkg/sentry/fs.(*File).Pwritev(0xc420e98000, 0x10d3f40, 0xc4206ea000, 0x10d2620, 0xc420f50000, 0x0, 0x1, 0x20002500, 0xd3, 0x0, ...)
	pkg/sentry/fs/file.go:294 +0x200
gvisor.googlesource.com/gvisor/pkg/sentry/syscalls/linux.performCallback(0xc420fc6000, 0xc420e98000, 0x20002640, 0xc42102c040, 0x10d2620, 0xc420f50000, 0x0, 0x1, 0x20002500, 0xd3, ...)
	pkg/sentry/syscalls/linux/sys_aio.go:264 +0x457
gvisor.googlesource.com/gvisor/pkg/sentry/syscalls/linux.submitCallback.func1()
	pkg/sentry/syscalls/linux/sys_aio.go:342 +0x11b
gvisor.googlesource.com/gvisor/pkg/sentry/fs.Async.func1(0xc420a762a0)
	pkg/sentry/fs/fs.go:82 +0x5d
created by gvisor.googlesource.com/gvisor/pkg/sentry/fs.Async
	pkg/sentry/fs/fs.go:80 +0x66