| From | Dongsu Park <> | Subject | [PATCH 11/11] evm: Don't update hmacs in user ns mounts | Date | Fri, 22 Dec 2017 15:32:35 +0100 |
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From: Seth Forshee <seth.forshee@canonical.com>
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> --- security/integrity/evm/evm_crypto.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c index bcd64baf..729f4545 100644 --- a/security/integrity/evm/evm_crypto.c +++ b/security/integrity/evm/evm_crypto.c @@ -190,7 +190,8 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry, int error; int size; - 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); -- 2.13.6
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