evm: Don't update hmacs in user ns mounts

The kernel should not calculate new hmacs for mounts done by
non-root users. Update evm_calc_hmac_or_hash() to refuse to
calculate new hmacs for mounts for non-init user namespaces.

Cc: linux-integrity@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: James Morris <james.l.morris@oracle.com>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Dongsu Park <dongsu@kinvolk.io>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
This commit is contained in:
Seth Forshee 2017-12-22 15:32:35 +01:00 committed by Eric W. Biederman
parent 6da6c0db53
commit a3a5c966a6
1 changed files with 2 additions and 1 deletions

View File

@ -200,7 +200,8 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry,
int size;
bool ima_present = false;
if (!(inode->i_opflags & IOP_XATTR))
if (!(inode->i_opflags & IOP_XATTR) ||
inode->i_sb->s_user_ns != &init_user_ns)
return -EOPNOTSUPP;
desc = init_desc(type);