integrity: Report error code in integrity_audit_msg() call sites

integrity_audit_msg() hides error codes by wrapping
integrity_audit_message() which obfuscates the underlying reason for the
failure.

Update integrity_audit_msg() to take a errno argument, and pass that
through to integrity_audit_message(). Then update call sites to
take caller's respective error codes.

ima_appraise_measurement() stores xattr_len as the return code, but
can replace it with a error code later. Therefore conditionally use
a code if rc < 0, otherwise report zero. Lastly, conditionally use
-EINVAL for ima_release_policy().

Signed-off-by: Frederick Lawler <fred@cloudflare.com>
Reviewed-by: Enrico Bravi <enrico.bravi@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

11 files changed, 35 insertions, 29 deletions

diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index b59e3f121b8a..5be9349afcd0 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -563,7 +563,7 @@ static int evm_protect_xattr(struct mnt_idmap *idmap,
 				    dentry->d_inode, dentry->d_name.name,
 				    "update_metadata",
 				    integrity_status_msg[evm_status],
-				    -EPERM, 0);
+				    -EPERM, 0, -EPERM);
 	}
 out:
 	/* Exception if the HMAC is not going to be calculated. */
@@ -588,7 +588,7 @@ out:
 		integrity_audit_msg(AUDIT_INTEGRITY_METADATA, d_backing_inode(dentry),
 				    dentry->d_name.name, "appraise_metadata",
 				    integrity_status_msg[evm_status],
-				    -EPERM, 0);
+				    -EPERM, 0, -EPERM);
 	return evm_status == INTEGRITY_PASS ? 0 : -EPERM;
 }
 
@@ -729,7 +729,7 @@ static int evm_inode_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		integrity_audit_msg(AUDIT_INTEGRITY_METADATA, d_backing_inode(dentry),
 				    dentry->d_name.name, "appraise_metadata",
 				    integrity_status_msg[evm_status],
-				    -EPERM, 0);
+				    -EPERM, 0, -EPERM);
 	return -EPERM;
 }
 
@@ -992,7 +992,8 @@ static int evm_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 
 	integrity_audit_msg(AUDIT_INTEGRITY_METADATA, d_backing_inode(dentry),
 			    dentry->d_name.name, "appraise_metadata",
-			    integrity_status_msg[evm_status], -EPERM, 0);
+			    integrity_status_msg[evm_status], -EPERM, 0,
+			    -EPERM);
 	return -EPERM;
 }
 
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 122d127e108d..f765bfe5db68 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -116,7 +116,7 @@ int ima_store_template(struct ima_template_entry *entry,
 		if (result < 0) {
 			integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode,
 					    template_name, op,
-					    audit_cause, result, 0);
+					    audit_cause, result, 0, result);
 			return result;
 		}
 	}
@@ -159,7 +159,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
 		ima_free_template_entry(entry);
 err_out:
 	integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename,
-			    op, cause, result, 0);
+			    op, cause, result, 0, result);
 }
 
 /**
@@ -330,7 +330,7 @@ out:
 
 		integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
 				    filename.name.name, "collect_data",
-				    audit_cause, result, 0);
+				    audit_cause, result, 0, result);
 
 		release_dentry_name_snapshot(&filename);
 	}
@@ -383,7 +383,7 @@ void ima_store_measurement(struct ima_iint_cache *iint, struct file *file,
 	result = ima_alloc_init_template(&event_data, &entry, template_desc);
 	if (result < 0) {
 		integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename,
-				    op, audit_cause, result, 0);
+				    op, audit_cause, result, 0, result);
 		return;
 	}
 
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index b280488e15fc..84c4dee2323c 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -564,7 +564,7 @@ out:
 		status = INTEGRITY_FAIL;
 		cause = "unverifiable-signature";
 		integrity_audit_msg(audit_msgno, inode, filename,
-				    op, cause, rc, 0);
+				    op, cause, rc, 0, rc < 0 ? rc : 0);
 	} else if (status != INTEGRITY_PASS) {
 		/* Fix mode, but don't replace file signatures. */
 		if ((ima_appraise & IMA_APPRAISE_FIX) && !try_modsig &&
@@ -589,7 +589,7 @@ out:
 		}
 
 		integrity_audit_msg(audit_msgno, inode, filename,
-				    op, cause, rc, 0);
+				    op, cause, rc, 0, rc < 0 ? rc : 0);
 	} else {
 		ima_cache_flags(iint, func);
 	}
@@ -752,7 +752,7 @@ static int validate_hash_algo(struct dentry *dentry,
 		path = NULL;
 
 	integrity_audit_msg(AUDIT_INTEGRITY_DATA, d_inode(dentry), path,
-			    "set_data", errmsg, -EACCES, 0);
+			    "set_data", errmsg, -EACCES, 0, -EACCES);
 
 	kfree(pathbuf);
 
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index 2a0bca554316..3b8174a91a34 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -592,11 +592,11 @@ static ssize_t ima_write_policy(struct file *file, const char __user *buf,
 	if (data[0] == '/') {
 		result = ima_read_policy(data);
 	} else if (ima_appraise & IMA_APPRAISE_POLICY) {
+		result = -EACCES;
 		pr_err("signed policy file (specified as an absolute pathname) required\n");
 		integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL,
 				    "policy_update", "signed policy required",
-				    1, 0);
-		result = -EACCES;
+				    result, 0, result);
 	} else {
 		ima_measure_raw_policy(data, datalen);
 		result = ima_parse_add_rule(data);
@@ -745,7 +745,8 @@ static int ima_release_policy(struct inode *inode, struct file *file)
 
 	pr_info("policy update %s\n", cause);
 	integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL,
-			    "policy_update", cause, !valid_policy, 0);
+			    "policy_update", cause, !valid_policy, 0,
+			    !valid_policy ? -EINVAL : 0);
 
 	if (!valid_policy) {
 		ima_delete_rules();
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index d53f4d89a53e..7a76e2686267 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -103,7 +103,7 @@ static int __init ima_add_boot_aggregate(void)
 	return 0;
 err_out:
 	integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, filename, op,
-			    audit_cause, result, 0);
+			    audit_cause, result, 0, result);
 	return result;
 }
 
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index ab1e53b3210d..9e80f40680d7 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -119,7 +119,7 @@ static int mmap_violation_check(enum ima_hooks func, struct file *file,
 			*pathname = ima_d_path(&file->f_path, pathbuf,
 					       filename);
 		integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, *pathname,
-				    "mmap_file", "mmapped_writers", rc, 0);
+				    "mmap_file", "mmapped_writers", rc, 0, rc);
 	}
 	return rc;
 }
@@ -466,7 +466,7 @@ static int process_measurement(struct file *file, const struct cred *cred,
 
 		integrity_audit_msg(AUDIT_INTEGRITY_DATA, file_inode(file),
 				    pathname, "collect_data",
-				    "denied-hash-algorithm", rc, 0);
+				    "denied-hash-algorithm", rc, 0, rc);
 	}
 out_locked:
 	if ((mask & MAY_WRITE) && test_bit(IMA_DIGSIG, &iint->atomic_flags) &&
@@ -579,7 +579,8 @@ static int ima_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
 	file = vma->vm_file;
 	pathname = ima_d_path(&file->f_path, &pathbuf, filename);
 	integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, pathname,
-			    "collect_data", "failed-mprotect", result, 0);
+			    "collect_data", "failed-mprotect", result, 0,
+			    result);
 	if (pathbuf)
 		__putname(pathbuf);
 
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 68d9a5e6c232..9013c962dc0b 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -1992,7 +1992,8 @@ ssize_t ima_parse_add_rule(char *rule)
 	entry = kzalloc_obj(*entry);
 	if (!entry) {
 		integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
-				    NULL, op, "-ENOMEM", -ENOMEM, audit_info);
+				    NULL, op, "-ENOMEM", -ENOMEM, audit_info,
+				    -ENOMEM);
 		return -ENOMEM;
 	}
 
@@ -2003,7 +2004,7 @@ ssize_t ima_parse_add_rule(char *rule)
 		ima_free_rule(entry);
 		integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
 				    NULL, op, "invalid-policy", result,
-				    audit_info);
+				    audit_info, result);
 		return result;
 	}
 
@@ -2421,7 +2422,7 @@ void ima_measure_loaded_policy(void)
 	rule = kmalloc(rule_len, GFP_KERNEL);
 	if (!rule) {
 		integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, event_name,
-				    op, "ENOMEM", result, 0);
+				    op, "ENOMEM", result, 0, result);
 		return;
 	}
 
@@ -2440,7 +2441,7 @@ void ima_measure_loaded_policy(void)
 			result = -E2BIG;
 			integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL,
 					    event_name, op, "rule_length",
-					    result, 0);
+					    result, 0, result);
 			rcu_read_unlock();
 			goto free_rule;
 		}
@@ -2454,7 +2455,7 @@ void ima_measure_loaded_policy(void)
 	file.buf = kmalloc(file_len, GFP_KERNEL);
 	if (!file.buf) {
 		integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, event_name,
-				    op, "ENOMEM", result, 0);
+				    op, "ENOMEM", result, 0, result);
 		goto free_rule;
 	}
 
diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c
index 0f1b7e4113c4..67782c004cdf 100644
--- a/security/integrity/ima/ima_queue.c
+++ b/security/integrity/ima/ima_queue.c
@@ -291,7 +291,7 @@ int ima_add_template_entry(struct ima_template_entry *entry, int violation,
 out:
 	mutex_unlock(&ima_extend_list_mutex);
 	integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename,
-			    op, audit_cause, result, audit_info);
+			    op, audit_cause, result, audit_info, result);
 	return result;
 }
 
diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
index 8a89236f926c..9bd80ca1159a 100644
--- a/security/integrity/ima/ima_template_lib.c
+++ b/security/integrity/ima/ima_template_lib.c
@@ -392,7 +392,7 @@ int ima_eventdigest_init(struct ima_event_data *event_data,
 	if (result) {
 		integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
 				    event_data->filename, "collect_data",
-				    "failed", result, 0);
+				    "failed", result, 0, result);
 		return result;
 	}
 	cur_digest = hash_hdr->digest;
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 0c581c03c5da..2ab6b7e34e7e 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -218,7 +218,8 @@ static inline void evm_load_x509(void)
 /* declarations */
 void integrity_audit_msg(int audit_msgno, struct inode *inode,
 			 const unsigned char *fname, const char *op,
-			 const char *cause, int result, int info);
+			 const char *cause, int result, int info,
+			 int errno);
 
 void integrity_audit_message(int audit_msgno, struct inode *inode,
 			     const unsigned char *fname, const char *op,
@@ -235,7 +236,7 @@ integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
 static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
 				       const unsigned char *fname,
 				       const char *op, const char *cause,
-				       int result, int info)
+				       int result, int info, int errno)
 {
 }
 
diff --git a/security/integrity/integrity_audit.c b/security/integrity/integrity_audit.c
index d8d9e5ff1cd2..2dd2d7e3916e 100644
--- a/security/integrity/integrity_audit.c
+++ b/security/integrity/integrity_audit.c
@@ -27,10 +27,11 @@ __setup("integrity_audit=", integrity_audit_setup);
 
 void integrity_audit_msg(int audit_msgno, struct inode *inode,
 			 const unsigned char *fname, const char *op,
-			 const char *cause, int result, int audit_info)
+			 const char *cause, int result, int audit_info,
+			 int errno)
 {
 	integrity_audit_message(audit_msgno, inode, fname, op, cause,
-				result, audit_info, 0);
+				result, audit_info, errno);
 }
 
 void integrity_audit_message(int audit_msgno, struct inode *inode,