GNU bug report logs - #30534
cp - Possible bugs when not preserving mode (explicit) and when copying special files

Previous Next

Full log

Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Declercq Laurent <l.declercq <at> nuxwin.com>
To: bug-coreutils <at> gnu.org
Subject: cp - Possible bugs when not preserving mode (explicit) and when
 copying special files
Date: Mon, 19 Feb 2018 11:22:48 +0100

I think that I did found at least two bugs in cp(1) command when the 
--no-preserve=mode option is involved and when copying special file. I 
describe each of them below.

1. Mode set on special files seem to be wrong:

Original file to copy: prw-rw-rw- 1 root staff 0 févr. 18 18:59 spfile
cp(1) command (run as root user): cp -r --no-preserve=mode spfile 
spfile_copy

Current result:

prwxr-xr-x 1 root staff 0 févr. 18 22:01 spfile_copy

Expected result (considering UMASK 0022):

prw-r--r-- 1 root staff 0 févr. 18 22:01 spfile_copy

The current behavior is due to the fact that mode used is 0777 while 
0666 should be used for files.

Possible fix: Differentiate directories from files in the copy_internal 
function.

2. Non-permission bits are preserved, even when the --no-preserve=mode 
option is involved.

Original file to copy: prwSrw-rw- 1 root staff 0 févr. 18 18:59 spfile
cp(1) command (run as root user): cp -r --no-preserve=mode spfile 
spfile_copy

Current result:

prwsr-xr-x 1 root staff 0 févr. 18 22:05 spfile_copy

Expected result (considering UMASK 0022 and without the first bug above):

prw-r--r-- 1 root staff 0 févr. 18 22:05 spfile_copy

Possible solution: Clear-out non-permission bits before calling mknod() 
and similar

Environment:
Linux jessie64 3.16.0-5-amd64 #1 SMP Debian 3.16.51-3+deb8u1 
(2018-01-08) x86_64 GNU/Linux
Checked against latest coreutils version.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.