Messages in this thread | | | Subject | Re: 2.6.10-rc2-mm4 | From | Stephen Smalley <> | Date | Thu, 02 Dec 2004 08:15:02 -0500 |
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On Wed, 2004-12-01 at 18:32, Jeffrey Mahoney wrote: > I took some more time to find a more optimal solution. Since ReiserFS is > currently the only filesystem that cares about this, it's far easier to keep > the whole mess internal to ReiserFS. The issue isn't about the treating of > "private" files in reiserfs, but rather just to avoid the looping of xattr > calls that selinux would create.
No. It is also about avoiding applying permission checks to these "private" inodes when reiserfs performs operations on them, e.g. when __get_xa_root() does a lookup_one_len(), there is ultimately a call to permission(inode, MAY_EXEC, nd), which triggers a security hook call, and SELinux will view this as an attempt by the current process to access the private directory. Simply disabling getxattr/setxattr for the private inodes won't change this, and you can't assume that most processes have permission to access the default file context (in fact, in a strict policy, that won't be the case).
Chris' suggestion of exporting this private flag via i_flags and having the VFS and/or security framework skip the security hook calls for such inodes is more reasonable, and should yield the same behavior as that current patchset (just without the extra security hook and the filesystem and SELinux-specific private flags).
-- Stephen Smalley <sds@epoch.ncsc.mil> National Security Agency
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