5 files changed, 67 insertions, 18 deletions

diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index ba9e4d792dd5..d9cd5ce14d2b 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -199,6 +199,7 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
 			    struct evm_ima_xattr_data **xattr_value,
 			    int *xattr_len)
 {
+	const char *audit_cause = "failed";
 	struct inode *inode = file_inode(file);
 	const char *filename = file->f_dentry->d_name.name;
 	int result = 0;
@@ -213,6 +214,12 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
 	if (!(iint->flags & IMA_COLLECTED)) {
 		u64 i_version = file_inode(file)->i_version;
 
+		if (file->f_flags & O_DIRECT) {
+			audit_cause = "failed(directio)";
+			result = -EACCES;
+			goto out;
+		}
+
 		/* use default hash algorithm */
 		hash.hdr.algo = ima_hash_algo;
 
@@ -233,9 +240,10 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
 				result = -ENOMEM;
 		}
 	}
+out:
 	if (result)
 		integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
-				    filename, "collect_data", "failed",
+				    filename, "collect_data", audit_cause,
 				    result, 0);
 	return result;
 }
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 291bf0f3a46d..d3113d4aaa3c 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -341,7 +341,7 @@ static int ima_protect_xattr(struct dentry *dentry, const char *xattr_name,
 	return 0;
 }
 
-static void ima_reset_appraise_flags(struct inode *inode)
+static void ima_reset_appraise_flags(struct inode *inode, int digsig)
 {
 	struct integrity_iint_cache *iint;
 
@@ -353,18 +353,22 @@ static void ima_reset_appraise_flags(struct inode *inode)
 		return;
 
 	iint->flags &= ~IMA_DONE_MASK;
+	if (digsig)
+		iint->flags |= IMA_DIGSIG;
 	return;
 }
 
 int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
 		       const void *xattr_value, size_t xattr_value_len)
 {
+	const struct evm_ima_xattr_data *xvalue = xattr_value;
 	int result;
 
 	result = ima_protect_xattr(dentry, xattr_name, xattr_value,
 				   xattr_value_len);
 	if (result == 1) {
-		ima_reset_appraise_flags(dentry->d_inode);
+		ima_reset_appraise_flags(dentry->d_inode,
+			 (xvalue->type == EVM_IMA_XATTR_DIGSIG) ? 1 : 0);
 		result = 0;
 	}
 	return result;
@@ -376,7 +380,7 @@ int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name)
 
 	result = ima_protect_xattr(dentry, xattr_name, NULL, 0);
 	if (result == 1) {
-		ima_reset_appraise_flags(dentry->d_inode);
+		ima_reset_appraise_flags(dentry->d_inode, 0);
 		result = 0;
 	}
 	return result;
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 1bde8e627766..ccd0ac8fa9a0 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -27,6 +27,36 @@
 
 static struct crypto_shash *ima_shash_tfm;
 
+/**
+ * ima_kernel_read - read file content
+ *
+ * This is a function for reading file content instead of kernel_read().
+ * It does not perform locking checks to ensure it cannot be blocked.
+ * It does not perform security checks because it is irrelevant for IMA.
+ *
+ */
+static int ima_kernel_read(struct file *file, loff_t offset,
+			   char *addr, unsigned long count)
+{
+	mm_segment_t old_fs;
+	char __user *buf = addr;
+	ssize_t ret;
+
+	if (!(file->f_mode & FMODE_READ))
+		return -EBADF;
+	if (!file->f_op->read && !file->f_op->aio_read)
+		return -EINVAL;
+
+	old_fs = get_fs();
+	set_fs(get_ds());
+	if (file->f_op->read)
+		ret = file->f_op->read(file, buf, count, &offset);
+	else
+		ret = do_sync_read(file, buf, count, &offset);
+	set_fs(old_fs);
+	return ret;
+}
+
 int ima_init_crypto(void)
 {
 	long rc;
@@ -104,7 +134,7 @@ static int ima_calc_file_hash_tfm(struct file *file,
 	while (offset < i_size) {
 		int rbuf_len;
 
-		rbuf_len = kernel_read(file, offset, rbuf, PAGE_SIZE);
+		rbuf_len = ima_kernel_read(file, offset, rbuf, PAGE_SIZE);
 		if (rbuf_len < 0) {
 			rc = rbuf_len;
 			break;
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 52ac6cf41f88..09baa335ebc7 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -81,7 +81,6 @@ static void ima_rdwr_violation_check(struct file *file)
 {
 	struct inode *inode = file_inode(file);
 	fmode_t mode = file->f_mode;
-	int must_measure;
 	bool send_tomtou = false, send_writers = false;
 	char *pathbuf = NULL;
 	const char *pathname;
@@ -92,18 +91,19 @@ static void ima_rdwr_violation_check(struct file *file)
 	mutex_lock(&inode->i_mutex);	/* file metadata: permissions, xattr */
 
 	if (mode & FMODE_WRITE) {
-		if (atomic_read(&inode->i_readcount) && IS_IMA(inode))
-			send_tomtou = true;
-		goto out;
+		if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) {
+			struct integrity_iint_cache *iint;
+			iint = integrity_iint_find(inode);
+			/* IMA_MEASURE is set from reader side */
+			if (iint && (iint->flags & IMA_MEASURE))
+				send_tomtou = true;
+		}
+	} else {
+		if ((atomic_read(&inode->i_writecount) > 0) &&
+		    ima_must_measure(inode, MAY_READ, FILE_CHECK))
+			send_writers = true;
 	}
 
-	must_measure = ima_must_measure(inode, MAY_READ, FILE_CHECK);
-	if (!must_measure)
-		goto out;
-
-	if (atomic_read(&inode->i_writecount) > 0)
-		send_writers = true;
-out:
 	mutex_unlock(&inode->i_mutex);
 
 	if (!send_tomtou && !send_writers)
@@ -214,8 +214,11 @@ static int process_measurement(struct file *file, const char *filename,
 		xattr_ptr = &xattr_value;
 
 	rc = ima_collect_measurement(iint, file, xattr_ptr, &xattr_len);
-	if (rc != 0)
+	if (rc != 0) {
+		if (file->f_flags & O_DIRECT)
+			rc = (iint->flags & IMA_PERMIT_DIRECTIO) ? 0 : -EACCES;
 		goto out_digsig;
+	}
 
 	pathname = filename ?: ima_d_path(&file->f_path, &pathbuf);
 
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 93873a450ff7..40a7488f6721 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -353,7 +353,7 @@ enum {
 	Opt_obj_user, Opt_obj_role, Opt_obj_type,
 	Opt_subj_user, Opt_subj_role, Opt_subj_type,
 	Opt_func, Opt_mask, Opt_fsmagic, Opt_uid, Opt_fowner,
-	Opt_appraise_type, Opt_fsuuid
+	Opt_appraise_type, Opt_fsuuid, Opt_permit_directio
 };
 
 static match_table_t policy_tokens = {
@@ -375,6 +375,7 @@ static match_table_t policy_tokens = {
 	{Opt_uid, "uid=%s"},
 	{Opt_fowner, "fowner=%s"},
 	{Opt_appraise_type, "appraise_type=%s"},
+	{Opt_permit_directio, "permit_directio"},
 	{Opt_err, NULL}
 };
 
@@ -622,6 +623,9 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 			else
 				result = -EINVAL;
 			break;
+		case Opt_permit_directio:
+			entry->flags |= IMA_PERMIT_DIRECTIO;
+			break;
 		case Opt_err:
 			ima_log_string(ab, "UNKNOWN", p);
 			result = -EINVAL;