[PATCH] rsync without --perms may set bogus permissions

[Christian Franke]

Rsync may set bogus permissions if --perms is not specified and ACLs are 
enabled. This happens if the destination directory was not created by 
Cygwin itself. Testcase:


$ cygcheck -f /bin/cygwin1.dll
cygwin-1.7.7-1

$ cygcheck -f /bin/rsync.exe
rsync-3.0.7-1

$ umask
0022

$ cmd /c 'mkdir C:\test'

$ cd /cygdrive/c/test

$ echo test >source

$ rsync -vvv source dest
...
got ACL-based default perms 5070 for directory . <<---rwx---
...

$ ls -l
-rw-r--r--+ 1 someone none 5 2010-11-25 19:50 source
----r-----+ 1 someone none 5 2010-11-25 19:50 dest

$ cat dest
cat: dest: Permission denied


For some (security?) reason rsync (without --perms) does not rely on 
permissions set by open(., O_CREAT, .). The permissions are set later 
based on the default ACL of the parent dir.

The problem is that the rsync function acls.c:rsync_acl_get_perms() 
expects that the default ACL has an "other" entry and that the "mask" 
entry has only 3 rwx-bits.

The default ACL returned by Cygwin does not contain an "other" entry in 
this case. The default "mask" is 0777 (OK or Cygwin bug?):

$ getfacl .
# file: .
# owner: someone
# group: none
user::rwx
group::---
group:root:rwx
group:SYSTEM:rwx
group:users:rwx
mask:rwx
other:---
default:user::rwx
default:group:root:rwx
default:group:SYSTEM:rwx
default:group:users:rwx
#default:other:... <<--- missing, expected by rsync
default:mask:rwx <<--- Cygwin returns 0777, rsync expects <= 07

With the above default ACL the function rsync_acl_get_perms() returns:
   (07 << 6) + ((uchar)0777 << 3) + 0200/*NO_ENTRY*/ = 05070
This is interpreted as ---rwx--- which results in a file not readable by 
the user.

The attached patch should fix this.

-- 
Christian Franke

-------------- next part --------------
A non-text attachment was scrubbed...
Name: rsync-3.0.7-perms.patch
Type: text/x-diff
Size: 827 bytes
Desc: not available
URL: <http://cygwin.com/pipermail/cygwin/attachments/20101125/d27c9beb/attachment.bin>
-------------- next part --------------
--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple