[PATCH] Miscellaneous bug and warning fixes

This patch fixes a couple of bugs revealed in new features recently
added to -mm1:
* fixes warnings due to inconsistent use of const struct inode *inode
* fixes bug that prevent a kernel from booting with audit on, and SELinux off
  due to a missing function in security/dummy.c
* fixes a bug that throws spurious audit_panic() messages due to a missing
  return just before an error_path label
* some reasonable house cleaning in audit_ipc_context(),
  audit_inode_context(), and audit_log_task_context()
Signed-off-by: NDustin Kirkland <dustin.kirkland@us.ibm.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

include/linux/security.h

@@ -1173,8 +1173,8 @@ struct security_operations {
 	int (*inode_getxattr) (struct dentry *dentry, char *name);
 	int (*inode_listxattr) (struct dentry *dentry);
 	int (*inode_removexattr) (struct dentry *dentry, char *name);
-	char *(*inode_xattr_getsuffix) (void);
-  	int (*inode_getsecurity)(struct inode *inode, const char *name, void *buffer, size_t size, int err);
+	const char *(*inode_xattr_getsuffix) (void);
+  	int (*inode_getsecurity)(const struct inode *inode, const char *name, void *buffer, size_t size, int err);
   	int (*inode_setsecurity)(struct inode *inode, const char *name, const void *value, size_t size, int flags);
   	int (*inode_listsecurity)(struct inode *inode, char *buffer, size_t buffer_size);
 
@@ -1686,7 +1686,7 @@ static inline const char *security_inode_xattr_getsuffix(void)
 	return security_ops->inode_xattr_getsuffix();
 }
 
-static inline int security_inode_getsecurity(struct inode *inode, const char *name, void *buffer, size_t size, int err)
+static inline int security_inode_getsecurity(const struct inode *inode, const char *name, void *buffer, size_t size, int err)
 {
 	if (unlikely (IS_PRIVATE (inode)))
 		return 0;
@@ -2338,7 +2338,7 @@ static inline const char *security_inode_xattr_getsuffix (void)
 	return NULL ;
 }
 
-static inline int security_inode_getsecurity(struct inode *inode, const char *name, void *buffer, size_t size, int err)
+static inline int security_inode_getsecurity(const struct inode *inode, const char *name, void *buffer, size_t size, int err)
 {
 	return -EOPNOTSUPP;
 }

kernel/auditsc.c

@@ -892,21 +892,20 @@ static void audit_log_task_context(struct audit_buffer *ab, gfp_t gfp_mask)
 	}
 
 	ctx = kmalloc(len, gfp_mask);
-	if (!ctx) {
+	if (!ctx)
 		goto error_path;
-		return;
-	}
 
 	len = security_getprocattr(current, "current", ctx, len);
 	if (len < 0 )
 		goto error_path;
 
 	audit_log_format(ab, " subj=%s", ctx);
+	return;
 
 error_path:
 	if (ctx)
 		kfree(ctx);
-	audit_panic("security_getprocattr error in audit_log_task_context");
+	audit_panic("error in audit_log_task_context");
 	return;
 }
 
@@ -1304,13 +1303,16 @@ void audit_putname(const char *name)
 void audit_inode_context(int idx, const struct inode *inode)
 {
 	struct audit_context *context = current->audit_context;
+	const char *suffix = security_inode_xattr_getsuffix();
 	char *ctx = NULL;
 	int len = 0;
 
-	if (!security_inode_xattr_getsuffix())
-		return;
+	if (!suffix)
+		goto ret;
 
-	len = security_inode_getsecurity(inode, (char *)security_inode_xattr_getsuffix(), NULL, 0, 0);
+	len = security_inode_getsecurity(inode, suffix, NULL, 0, 0);
+	if (len == -EOPNOTSUPP)
+		goto ret;
 	if (len < 0) 
 		goto error_path;
 
@@ -1318,18 +1320,19 @@ void audit_inode_context(int idx, const struct inode *inode)
 	if (!ctx) 
 		goto error_path;
 
-	len = security_inode_getsecurity(inode, (char *)security_inode_xattr_getsuffix(), ctx, len, 0);
+	len = security_inode_getsecurity(inode, suffix, ctx, len, 0);
 	if (len < 0)
 		goto error_path;
 
 	kfree(context->names[idx].ctx);
 	context->names[idx].ctx = ctx;
-	return;
+	goto ret;
 
 error_path:
 	if (ctx)
 		kfree(ctx);
 	audit_panic("error in audit_inode_context");
+ret:
 	return;
 }
 

security/dummy.c

@@ -378,7 +378,7 @@ static int dummy_inode_removexattr (struct dentry *dentry, char *name)
 	return 0;
 }
 
-static int dummy_inode_getsecurity(struct inode *inode, const char *name, void *buffer, size_t size, int err)
+static int dummy_inode_getsecurity(const struct inode *inode, const char *name, void *buffer, size_t size, int err)
 {
 	return -EOPNOTSUPP;
 }
@@ -393,6 +393,11 @@ static int dummy_inode_listsecurity(struct inode *inode, char *buffer, size_t bu
 	return 0;
 }
 
+static const char *dummy_inode_xattr_getsuffix(void)
+{
+	return NULL;
+}
+
 static int dummy_file_permission (struct file *file, int mask)
 {
 	return 0;
@@ -930,6 +935,7 @@ void security_fixup_ops (struct security_operations *ops)
 	set_to_dummy_if_null(ops, inode_getxattr);
 	set_to_dummy_if_null(ops, inode_listxattr);
 	set_to_dummy_if_null(ops, inode_removexattr);
+	set_to_dummy_if_null(ops, inode_xattr_getsuffix);
 	set_to_dummy_if_null(ops, inode_getsecurity);
 	set_to_dummy_if_null(ops, inode_setsecurity);
 	set_to_dummy_if_null(ops, inode_listsecurity);

security/selinux/hooks.c

@@ -2247,7 +2247,7 @@ static const char *selinux_inode_xattr_getsuffix(void)
  *
  * Permission check is handled by selinux_inode_getxattr hook.
  */
-static int selinux_inode_getsecurity(struct inode *inode, const char *name, void *buffer, size_t size, int err)
+static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void *buffer, size_t size, int err)
 {
 	struct inode_security_struct *isec = inode->i_security;