Limit most file mmaps to the range of an int64.

In the general case, files may have offsets between MaxInt64 and MaxUint64; in
Linux pgoff is consistently represented by an unsigned long, and in gVisor the
offset types in memmap.MappableRange are uint64. However, regular file mmap is
constrained to int64 offsets (on 64-bit systems) by
mm/mmap.c:file_mmap_size_max() => MAX_LFS_FILESIZE == LLONG_MAX.

As a related fix, check for chunkStart overflow in fsutil.HostFileMapper; chunk
offsets are uint64s, but as noted above some file types may use uint64 offsets
beyond MaxInt64.

Reported-by: syzbot+71342a1585aed97ed9f7@syzkaller.appspotmail.com
PiperOrigin-RevId: 397136751

0 files changed, 0 insertions, 0 deletions