From: Dmitry Kasatkin <d.kasatkin@samsung.com>
Date: Fri, 15 Aug 2014 10:49:22 +0000 (+0300)
Subject: evm: prevent passing integrity check if xattr read fails
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=1f1009791b2e81f106d4809007720495ba3ed90c;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

evm: prevent passing integrity check if xattr read fails

This patch fixes a bug, where evm_verify_hmac() returns INTEGRITY_PASS
if inode->i_op->getxattr() returns an error in evm_find_protected_xattrs.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
---

diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index fb71f55295dc..40220124364c 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -126,14 +126,15 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry,
 	rc = vfs_getxattr_alloc(dentry, XATTR_NAME_EVM, (char **)&xattr_data, 0,
 				GFP_NOFS);
 	if (rc <= 0) {
-		if (rc == 0)
-			evm_status = INTEGRITY_FAIL; /* empty */
-		else if (rc == -ENODATA) {
+		evm_status = INTEGRITY_FAIL;
+		if (rc == -ENODATA) {
 			rc = evm_find_protected_xattrs(dentry);
 			if (rc > 0)
 				evm_status = INTEGRITY_NOLABEL;
 			else if (rc == 0)
 				evm_status = INTEGRITY_NOXATTRS; /* new file */
+		} else if (rc == -EOPNOTSUPP) {
+			evm_status = INTEGRITY_UNKNOWN;
 		}
 		goto out;
 	}