On Mon, Dec 24, 2018 at 1:14 PM OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> wrote: > > Matteo Croce <mcroce@xxxxxxxxxx> writes: > > > The FAT32 File System Specification[1] states that: > > > > If DIR_Name[0] == 0x00, then the directory entry is free, and there > > are no allocated directory entries after this one. > > > > The special 0 value, indicates to FAT file system driver code that > > the rest of the entries in this directory do not need to be examined > > because they are all free. > > > > This is not enforced by Linux, and is possible to read garbage if not > > all dirents after the last one are filled with zeroes. > > > > [1] http://download.microsoft.com/download/1/6/1/161ba512-40e2-4cc9-843a-923143f3456c/fatgen103.doc > > > > Reported-by: Timothy Redaelli <tredaelli@xxxxxxxxxx> > > Signed-off-by: Matteo Croce <mcroce@xxxxxxxxxx> > > We have to handle all paths that is using fat_get_entry(), to make > consistent behavior. > > With quick check, there are still several issues remaining. Please check > more. For example, looks like fat_parse_long()/fat_search_long() path is > missing, and fat_get_dotdot_entry(), fat_subdirs() too. > If I put the check in fat_get_short_entry(), then fat_get_dotdot_entry() and fat_subdirs() are covered too. Is there any drawback in doing this? > (while adding new entry, if we found zeroed entry, we would be better to > warn about fsck.) > Ok > Thanks. > -- > OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> Thanks, -- Matteo Croce per aspera ad upstream
