panic: invalid allocation length: 0x0

goroutine 58273 [running]:
gvisor.googlesource.com/gvisor/pkg/sentry/platform/filemem.(*FileMem).Allocate(0xc42029a000, 0x0, 0x3, 0x0, 0x0, 0x0, 0x0)
	pkg/sentry/platform/filemem/filemem.go:232 +0x765
gvisor.googlesource.com/gvisor/pkg/sentry/fs/tmpfs.(*fileReadWriter).WriteFromBlocks(0xc4200f02a0, 0x7fea071ff080, 0xffffffffffffffff, 0x0, 0xa1, 0x0, 0x0, 0x0)
	pkg/sentry/fs/tmpfs/inode_file.go:411 +0x461
gvisor.googlesource.com/gvisor/pkg/sentry/safemem.(Writer).WriteFromBlocks-fm(0x7fea071ff080, 0xffffffffffffffff, 0x0, 0xa1, 0x20000121, 0x7fea071ff080, 0xffffffffffffffff)
	pkg/sentry/mm/io.go:309 +0x76
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).withInternalMappings(0xc421812000, 0x10d3c20, 0xc4205a8080, 0x20000080, 0x20000121, 0x1, 0xc420a0ab68, 0xc420a0a968, 0x47b965, 0x47ed19)
	pkg/sentry/mm/io.go:464 +0x88f
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).withVecInternalMappings(0xc421812000, 0x10d3c20, 0xc4205a8080, 0x0, 0x1, 0x20000080, 0xa1, 0x1, 0xc420a0ab68, 0x0, ...)
	pkg/sentry/mm/io.go:533 +0x974
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).CopyInTo(0xc421812000, 0x10d3c20, 0xc4205a8080, 0x0, 0x1, 0x20000080, 0xa1, 0x10c4740, 0xc4200f02a0, 0x153c0aa63f8d0000, ...)
	pkg/sentry/mm/io.go:309 +0x211
gvisor.googlesource.com/gvisor/pkg/sentry/usermem.IOSequence.CopyInTo(0x10d2300, 0xc421812000, 0x0, 0x1, 0x20000080, 0xa1, 0x0, 0x10d3c20, 0xc4205a8080, 0x10c4740, ...)
	pkg/sentry/usermem/usermem.go:528 +0xcf
gvisor.googlesource.com/gvisor/pkg/sentry/fs/tmpfs.(*fileInodeOperations).write(0xc42086ad80, 0x10d3c20, 0xc4205a8080, 0x10d2300, 0xc421812000, 0x0, 0x1, 0x20000080, 0xa1, 0x0, ...)
	pkg/sentry/fs/tmpfs/inode_file.go:289 +0x1cb
gvisor.googlesource.com/gvisor/pkg/sentry/fs/tmpfs.(*regularFileOperations).Write(0xc420a50010, 0x10d3c20, 0xc4205a8080, 0xc420e6a870, 0x10d2300, 0xc421812000, 0x0, 0x1, 0x20000080, 0xa1, ...)
	pkg/sentry/fs/tmpfs/file_regular.go:50 +0xb9
gvisor.googlesource.com/gvisor/pkg/sentry/fs.(*File).Pwritev(0xc420e6a870, 0x10d3c20, 0xc4205a8080, 0x10d2300, 0xc421812000, 0x0, 0x1, 0x20000080, 0xa1, 0x0, ...)
	pkg/sentry/fs/file.go:294 +0x200
gvisor.googlesource.com/gvisor/pkg/sentry/syscalls/linux.performCallback(0xc420779600, 0xc420e6a870, 0x20000180, 0xc42070e100, 0x10d2300, 0xc421812000, 0x0, 0x1, 0x20000080, 0xa1, ...)
	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(0xc420930150)
	pkg/sentry/fs/fs.go:82 +0x5d
created by gvisor.googlesource.com/gvisor/pkg/sentry/fs.Async
	pkg/sentry/fs/fs.go:80 +0x66