[bug #26598] UDF file system support does not work well

[Giuseppe Caizzone]

URL:
  <http://savannah.gnu.org/bugs/?26598>

                 Summary: UDF file system support does not work well
                 Project: GNU GRUB
            Submitted by: peppepz
            Submitted on: dom 17 mag 2009 08:15:39 GMT
                Category: Filesystem
                Severity: Major
                Priority: 5 - Normal
              Item Group: None
                  Status: None
                 Privacy: Public
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: svn trunk (about 2009-05-10)
         Reproducibility: Every Time
         Planned Release: 

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Details:

Hello,
I tried to use grub2 (from svn trunk) to boot from a UDF-formatted partition
on a usb key, and it didn't work. grub displayed "invalid part ref".

The partition was 2 GB large, formatted by mkudffs 1.0.0b2 with the default
2048 bytes block size, and it only contained the files copied there by
grub-install, plus grub.cfg and device.map.

Since I did not know anything about the UDF file system I added some
grub_printf()s here and there, and it looked like grub was trying to read
directory entries from the body of an ELF file.
I think the problem was that grub_udf_read_block() makes a mixed comparison
between a byte count and a block count:

|    if (fileblock < U32 (ad->length))

but ad->length is in bytes not blocks (see the attached patch for context).

I made the quick patch I am attaching and now grub appears to work for me. I
do not know if the patch is effectively correct, but since it happened to work
for me, I thought it wouldn't harm to post it here.



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File Attachments:


-------------------------------------------------------
Date: dom 17 mag 2009 08:15:39 GMT  Name: udf-fix.diff  Size: 2kB   By:
peppepz

<http://savannah.gnu.org/bugs/download.php?file_id=18153>

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