evm: labeling pseudo filesystems exception

To prevent offline stripping of existing file xattrs and relabeling of
them at runtime, EVM allows only newly created files to be labeled.  As
pseudo filesystems are not persistent, stripping of xattrs is not a
concern.

Some LSMs defer file labeling on pseudo filesystems.  This patch
permits the labeling of existing files on pseudo files systems.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This commit is contained in:
Mimi Zohar 2015-04-21 13:59:31 -04:00
parent a18d0cbfab
commit 5101a1850b

View File

@ -296,6 +296,17 @@ static int evm_protect_xattr(struct dentry *dentry, const char *xattr_name,
iint = integrity_iint_find(d_backing_inode(dentry));
if (iint && (iint->flags & IMA_NEW_FILE))
return 0;
/* exception for pseudo filesystems */
if (dentry->d_inode->i_sb->s_magic == TMPFS_MAGIC
|| dentry->d_inode->i_sb->s_magic == SYSFS_MAGIC)
return 0;
integrity_audit_msg(AUDIT_INTEGRITY_METADATA,
dentry->d_inode, dentry->d_name.name,
"update_metadata",
integrity_status_msg[evm_status],
-EPERM, 0);
}
out:
if (evm_status != INTEGRITY_PASS)