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>
This commit is contained in:
Dmitry Kasatkin 2014-08-15 13:49:22 +03:00 committed by Mimi Zohar
parent e7d021e283
commit 1f1009791b

View File

@ -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;
}