evm: reset EVM status when file attributes changes
EVM verification status is cached in iint->evm_status
and if it was successful, never re-verified again when
IMA passes 'iint' to evm_verifyxattr().
When file attribute or extended attributes changes we may
wish to re-verify EVM integrity as well. For example,
after setting digital signature we may need to re-verify
the signature and update iint->flags that there is EVM
signature.
This patch enables that by resetting evm_status to
INTEGRITY_UKNOWN state.
Changes in v2:
* Flag setting moved to EVM layer
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 420d94d..f716025 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -358,6 +358,15 @@
return evm_protect_xattr(dentry, xattr_name, NULL, 0);
}
+static void evm_reset_status(struct inode *inode)
+{
+ struct integrity_iint_cache *iint;
+
+ iint = integrity_iint_find(inode);
+ if (iint)
+ iint->evm_status = INTEGRITY_UNKNOWN;
+}
+
/**
* evm_inode_post_setxattr - update 'security.evm' to reflect the changes
* @dentry: pointer to the affected dentry
@@ -378,6 +387,8 @@
&& !posix_xattr_acl(xattr_name)))
return;
+ evm_reset_status(dentry->d_inode);
+
evm_update_evmxattr(dentry, xattr_name, xattr_value, xattr_value_len);
}
@@ -396,6 +407,8 @@
if (!evm_initialized || !evm_protected_xattr(xattr_name))
return;
+ evm_reset_status(dentry->d_inode);
+
evm_update_evmxattr(dentry, xattr_name, NULL, 0);
}
