• Phillip Lougher's avatar
    Squashfs: fix i_blocks calculation with extended regular files · 3d4a1c80
    Phillip Lougher authored
    The le64_to_cpu() forces the calculation to be unsigned, with
    the effect that it can underflow leading to an incorrect large
    value.
    
    This bug only triggers in rare(ish) circumstances, an empty file
    encoded as an extended regular file or a completely sparse file.
    Normally empty files are encoded as a regular file rather than as
    an extended regular file (and the regular file i_blocks calculation
    doesn't have this bug).  To save space regular file inodes are
    optimised to encode the most commonly occurring files.  Less
    common regular files are encoded using extended regular file inodes
    which contain extra information.
    
    Empty files with nlinks greater than 1, and or empty files
    with extended attributes are encoded using extended regular file
    inodes and they will hit this bug.
    Signed-off-by: default avatarPhillip Lougher <phillip@squashfs.org.uk>
    3d4a1c80
inode.c 12.4 KB