[Bug-cpio] cpio: checksum error on 64-bit machines

[Jim Castleberry]

Package: cpio
Version: 2.6-7

[ The above pseudo-headers are for the Debian email bug reporting system. ]

Vanilla cpio 2.6 sometimes writes bad crcs in the cpio header on 64-bit 
machines.  It seems to
show up only on some large files.  The symptom is that the crc stored in the 
file appears to
be shifted by one nibble, and fails the crc check on copy-out.

For example using the Openoffice 2.0 release from openoffice.org mirrors, eg
     
http://mirrors.ibiblio.org/pub/mirrors/openoffice/stable/2.0.0/OOo_2.0.0_LinuxIntel_install.tar.gz

   $ uname -a Linux centos 2.6.9-11.ELsmp #1 SMP Wed Jun 8 16:59:12 CDT 2005 
x86_64 x86_64 x86_64 GNU/Linux
   $ cpio --version cpio (GNU cpio) 2.6
   $ echo OOo_2.0.0_LinuxIntel_install.tar.gz |cpio -o --format=crc >test.cpio
   207906 blocks
   $ cpio -i --only-verify-crc <test.cpio
   cpio: OOo_2.0.0_LinuxIntel_install.tar.gz: checksum error (0x32bf3b47, 
should be 0x332bf3b4)
   207906 blocks
   $

Doing the same thing on a 32-bit i386 machine running the same software works 
properly.
The only differences in the output file are in the c_maj, m_min, and c_chksum 
fields of
the cpio header.  All the other fields and the file data are the same and 
correct.

The cpio-2.5 that comes with the current Redhat EL (cpio-2.5-8.RHEL4) exhibits 
the
identical problem.

The bug was reported to Redhat by Michael J. Donahue in 1998 in cpio 2.4.2 on 
Redhat 4.1
for alpha:
     http://www.redhat.com/archives/axp-list/1998-March/msg00494.html
but apparently never addressed.

It was rediscovered by Tom Vier in 2001 2.4.2 on Debian and fixed by the debian 
folks:
     http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=100456
Looking at their patches for 2.4.2 at
     http://ftp.debian.org/pool/main/c/cpio/cpio_2.4.2-39woody1.diff.gz
the fix was in function write_out_header():
   @@ -60,7 +61,7 @@
               file_hdr->c_gid, file_hdr->c_nlink, file_hdr->c_mtime,
             file_hdr->c_filesize, file_hdr->c_dev_maj, file_hdr->c_dev_min,
           file_hdr->c_rdev_maj, file_hdr->c_rdev_min, file_hdr->c_namesize,
   -           file_hdr->c_chksum);
   +           file_hdr->c_chksum & 0xffffffff);
          tape_buffered_write (ascii_header, out_des, 110L);

          /* Write file name to output.  */

I applied that same change to the vanilla 2.6 copyout.c and it fixes the 
problem.
Patch is attached.

Note 1: The current Redhat ships cpio 2.5 with this defect.  I've reported it 
as bug 171649.
Note 2: Debian carried the patch over to their patches for cpio 2.5 but seems 
to have
         dropped it from their patches for 2.6.  So I'd guess that their 2.6 
has the same problem
         too, though I haven't tried it.  I'm Cc:'ing this email to the Debian 
bug reporting
         system.


--- cpio-2.6/src/copyout.c.orig 2004-10-14 03:14:03.000000000 -0600
+++ cpio-2.6/src/copyout.c      2005-10-24 12:28:43.832281758 -0600
@@ -311,7 +311,7 @@
               file_hdr->c_gid, file_hdr->c_nlink, file_hdr->c_mtime,
             file_hdr->c_filesize, file_hdr->c_dev_maj, file_hdr->c_dev_min,
           file_hdr->c_rdev_maj, file_hdr->c_rdev_min, file_hdr->c_namesize,
-              file_hdr->c_chksum);
+              file_hdr->c_chksum & 0xffffffff);
       tape_buffered_write (ascii_header, out_des, 110L);
 
       /* Write file name to output.  */