1 files changed, 85 insertions, 83 deletions

diff --git a/kernel/params.c b/kernel/params.c
index 14d66070757b..b96cfd693c99 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -1,18 +1,20 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
-/* Helpers for initial module or kernel cmdline parsing
-   Copyright (C) 2001 Rusty Russell.
-
-*/
-#include <linux/kernel.h>
-#include <linux/string.h>
+/*
+ * Helpers for initial module or kernel cmdline parsing
+ * Copyright (C) 2001 Rusty Russell.
+ */
+#include <linux/ctype.h>
+#include <linux/device.h>
+#include <linux/err.h>
 #include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/kstrtox.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
-#include <linux/device.h>
-#include <linux/err.h>
-#include <linux/slab.h>
-#include <linux/ctype.h>
+#include <linux/overflow.h>
 #include <linux/security.h>
+#include <linux/slab.h>
+#include <linux/string.h>
 
 #ifdef CONFIG_SYSFS
 /* Protects all built-in parameters, modules use their own param_lock */
@@ -47,7 +49,7 @@ static void *kmalloc_parameter(unsigned int size)
 {
 	struct kmalloced_param *p;
 
-	p = kmalloc(sizeof(*p) + size, GFP_KERNEL);
+	p = kmalloc(size_add(sizeof(*p), size), GFP_KERNEL);
 	if (!p)
 		return NULL;
 
@@ -119,9 +121,7 @@ static int parse_one(char *param,
 		     unsigned num_params,
 		     s16 min_level,
 		     s16 max_level,
-		     void *arg,
-		     int (*handle_unknown)(char *param, char *val,
-				     const char *doing, void *arg))
+		     void *arg, parse_unknown_fn handle_unknown)
 {
 	unsigned int i;
 	int err;
@@ -164,9 +164,7 @@ char *parse_args(const char *doing,
 		 unsigned num,
 		 s16 min_level,
 		 s16 max_level,
-		 void *arg,
-		 int (*unknown)(char *param, char *val,
-				const char *doing, void *arg))
+		 void *arg, parse_unknown_fn unknown)
 {
 	char *param, *val, *err = NULL;
 
@@ -263,17 +261,22 @@ EXPORT_SYMBOL_GPL(param_set_uint_minmax);
 
 int param_set_charp(const char *val, const struct kernel_param *kp)
 {
-	if (strlen(val) > 1024) {
+	size_t len, maxlen = 1024;
+
+	len = strnlen(val, maxlen + 1);
+	if (len == maxlen + 1) {
 		pr_err("%s: string parameter too long\n", kp->name);
 		return -ENOSPC;
 	}
 
 	maybe_kfree_parameter(*(char **)kp->arg);
 
-	/* This is a hack.  We can't kmalloc in early boot, and we
-	 * don't need to; this mangled commandline is preserved. */
+	/*
+	 * This is a hack. We can't kmalloc() in early boot, and we
+	 * don't need to; this mangled commandline is preserved.
+	 */
 	if (slab_is_available()) {
-		*(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
+		*(char **)kp->arg = kmalloc_parameter(len + 1);
 		if (!*(char **)kp->arg)
 			return -ENOMEM;
 		strcpy(*(char **)kp->arg, val);
@@ -310,7 +313,7 @@ int param_set_bool(const char *val, const struct kernel_param *kp)
 	if (!val) val = "1";
 
 	/* One of =[yYnN01] */
-	return strtobool(val, kp->arg);
+	return kstrtobool(val, kp->arg);
 }
 EXPORT_SYMBOL(param_set_bool);
 
@@ -330,7 +333,7 @@ EXPORT_SYMBOL(param_ops_bool);
 
 int param_set_bool_enable_only(const char *val, const struct kernel_param *kp)
 {
-	int err = 0;
+	int err;
 	bool new_value;
 	bool orig_value = *(bool *)kp->arg;
 	struct kernel_param dummy_kp = *kp;
@@ -510,13 +513,14 @@ EXPORT_SYMBOL(param_array_ops);
 int param_set_copystring(const char *val, const struct kernel_param *kp)
 {
 	const struct kparam_string *kps = kp->str;
+	const size_t len = strnlen(val, kps->maxlen);
 
-	if (strlen(val)+1 > kps->maxlen) {
+	if (len == kps->maxlen) {
 		pr_err("%s: string doesn't fit in %u chars.\n",
 		       kp->name, kps->maxlen-1);
 		return -ENOSPC;
 	}
-	strcpy(kps->string, val);
+	memcpy(kps->string, val, len + 1);
 	return 0;
 }
 EXPORT_SYMBOL(param_set_copystring);
@@ -535,7 +539,7 @@ const struct kernel_param_ops param_ops_string = {
 EXPORT_SYMBOL(param_ops_string);
 
 /* sysfs output in /sys/modules/XYZ/parameters/ */
-#define to_module_attr(n) container_of(n, struct module_attribute, attr)
+#define to_module_attr(n) container_of_const(n, struct module_attribute, attr)
 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
 
 struct param_attribute
@@ -548,17 +552,17 @@ struct module_param_attrs
 {
 	unsigned int num;
 	struct attribute_group grp;
-	struct param_attribute attrs[];
+	struct param_attribute attrs[] __counted_by(num);
 };
 
 #ifdef CONFIG_SYSFS
-#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
+#define to_param_attr(n) container_of_const(n, struct param_attribute, mattr)
 
-static ssize_t param_attr_show(struct module_attribute *mattr,
+static ssize_t param_attr_show(const struct module_attribute *mattr,
 			       struct module_kobject *mk, char *buf)
 {
 	int count;
-	struct param_attribute *attribute = to_param_attr(mattr);
+	const struct param_attribute *attribute = to_param_attr(mattr);
 
 	if (!attribute->param->ops->get)
 		return -EPERM;
@@ -570,12 +574,12 @@ static ssize_t param_attr_show(struct module_attribute *mattr,
 }
 
 /* sysfs always hands a nul-terminated string in buf.  We rely on that. */
-static ssize_t param_attr_store(struct module_attribute *mattr,
+static ssize_t param_attr_store(const struct module_attribute *mattr,
 				struct module_kobject *mk,
 				const char *buf, size_t len)
 {
  	int err;
-	struct param_attribute *attribute = to_param_attr(mattr);
+	const struct param_attribute *attribute = to_param_attr(mattr);
 
 	if (!attribute->param->ops->set)
 		return -EPERM;
@@ -648,35 +652,32 @@ static __modinit int add_sysfs_param(struct module_kobject *mk,
 	}
 
 	/* Enlarge allocations. */
-	new_mp = krealloc(mk->mp,
-			  sizeof(*mk->mp) +
-			  sizeof(mk->mp->attrs[0]) * (mk->mp->num + 1),
+	new_mp = krealloc(mk->mp, struct_size(mk->mp, attrs, mk->mp->num + 1),
 			  GFP_KERNEL);
 	if (!new_mp)
 		return -ENOMEM;
 	mk->mp = new_mp;
+	mk->mp->num++;
 
 	/* Extra pointer for NULL terminator */
-	new_attrs = krealloc(mk->mp->grp.attrs,
-			     sizeof(mk->mp->grp.attrs[0]) * (mk->mp->num + 2),
-			     GFP_KERNEL);
+	new_attrs = krealloc_array(mk->mp->grp.attrs, mk->mp->num + 1,
+				   sizeof(mk->mp->grp.attrs[0]), GFP_KERNEL);
 	if (!new_attrs)
 		return -ENOMEM;
 	mk->mp->grp.attrs = new_attrs;
 
 	/* Tack new one on the end. */
-	memset(&mk->mp->attrs[mk->mp->num], 0, sizeof(mk->mp->attrs[0]));
-	sysfs_attr_init(&mk->mp->attrs[mk->mp->num].mattr.attr);
-	mk->mp->attrs[mk->mp->num].param = kp;
-	mk->mp->attrs[mk->mp->num].mattr.show = param_attr_show;
+	memset(&mk->mp->attrs[mk->mp->num - 1], 0, sizeof(mk->mp->attrs[0]));
+	sysfs_attr_init(&mk->mp->attrs[mk->mp->num - 1].mattr.attr);
+	mk->mp->attrs[mk->mp->num - 1].param = kp;
+	mk->mp->attrs[mk->mp->num - 1].mattr.show = param_attr_show;
 	/* Do not allow runtime DAC changes to make param writable. */
 	if ((kp->perm & (S_IWUSR | S_IWGRP | S_IWOTH)) != 0)
-		mk->mp->attrs[mk->mp->num].mattr.store = param_attr_store;
+		mk->mp->attrs[mk->mp->num - 1].mattr.store = param_attr_store;
 	else
-		mk->mp->attrs[mk->mp->num].mattr.store = NULL;
-	mk->mp->attrs[mk->mp->num].mattr.attr.name = (char *)name;
-	mk->mp->attrs[mk->mp->num].mattr.attr.mode = kp->perm;
-	mk->mp->num++;
+		mk->mp->attrs[mk->mp->num - 1].mattr.store = NULL;
+	mk->mp->attrs[mk->mp->num - 1].mattr.attr.name = (char *)name;
+	mk->mp->attrs[mk->mp->num - 1].mattr.attr.mode = kp->perm;
 
 	/* Fix up all the pointers, since krealloc can move us */
 	for (i = 0; i < mk->mp->num; i++)
@@ -742,8 +743,10 @@ void module_param_sysfs_remove(struct module *mod)
 {
 	if (mod->mkobj.mp) {
 		sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
-		/* We are positive that no one is using any param
-		 * attrs at this point.  Deallocate immediately. */
+		/*
+		 * We are positive that no one is using any param
+		 * attrs at this point. Deallocate immediately.
+		 */
 		free_module_param_attrs(&mod->mkobj);
 	}
 }
@@ -758,38 +761,35 @@ void destroy_params(const struct kernel_param *params, unsigned num)
 			params[i].ops->free(params[i].arg);
 }
 
-static struct module_kobject * __init locate_module_kobject(const char *name)
+struct module_kobject __modinit * lookup_or_create_module_kobject(const char *name)
 {
 	struct module_kobject *mk;
 	struct kobject *kobj;
 	int err;
 
 	kobj = kset_find_obj(module_kset, name);
-	if (kobj) {
-		mk = to_module_kobject(kobj);
-	} else {
-		mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
-		BUG_ON(!mk);
-
-		mk->mod = THIS_MODULE;
-		mk->kobj.kset = module_kset;
-		err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
-					   "%s", name);
-#ifdef CONFIG_MODULES
-		if (!err)
-			err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
-#endif
-		if (err) {
-			kobject_put(&mk->kobj);
-			pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
-				name, err);
-			return NULL;
-		}
+	if (kobj)
+		return to_module_kobject(kobj);
+
+	mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
+	if (!mk)
+		return NULL;
 
-		/* So that we hold reference in both cases. */
-		kobject_get(&mk->kobj);
+	mk->mod = THIS_MODULE;
+	mk->kobj.kset = module_kset;
+	err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL, "%s", name);
+	if (IS_ENABLED(CONFIG_MODULES) && !err)
+		err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
+	if (err) {
+		kobject_put(&mk->kobj);
+		pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
+			name, err);
+		return NULL;
 	}
 
+	/* So that we hold reference in both cases. */
+	kobject_get(&mk->kobj);
+
 	return mk;
 }
 
@@ -800,7 +800,7 @@ static void __init kernel_add_sysfs_param(const char *name,
 	struct module_kobject *mk;
 	int err;
 
-	mk = locate_module_kobject(name);
+	mk = lookup_or_create_module_kobject(name);
 	if (!mk)
 		return;
 
@@ -842,21 +842,21 @@ static void __init param_sysfs_builtin(void)
 		dot = strchr(kp->name, '.');
 		if (!dot) {
 			/* This happens for core_param() */
-			strcpy(modname, "kernel");
+			strscpy(modname, "kernel");
 			name_len = 0;
 		} else {
 			name_len = dot - kp->name + 1;
-			strlcpy(modname, kp->name, name_len);
+			strscpy(modname, kp->name, name_len);
 		}
 		kernel_add_sysfs_param(modname, kp, name_len);
 	}
 }
 
-ssize_t __modver_version_show(struct module_attribute *mattr,
+ssize_t __modver_version_show(const struct module_attribute *mattr,
 			      struct module_kobject *mk, char *buf)
 {
-	struct module_version_attribute *vattr =
-		container_of(mattr, struct module_version_attribute, mattr);
+	const struct module_version_attribute *vattr =
+		container_of_const(mattr, struct module_version_attribute, mattr);
 
 	return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version);
 }
@@ -871,7 +871,7 @@ static void __init version_sysfs_builtin(void)
 	int err;
 
 	for (vattr = __start___modver; vattr < __stop___modver; vattr++) {
-		mk = locate_module_kobject(vattr->module_name);
+		mk = lookup_or_create_module_kobject(vattr->module_name);
 		if (mk) {
 			err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
 			WARN_ON_ONCE(err);
@@ -887,7 +887,7 @@ static ssize_t module_attr_show(struct kobject *kobj,
 				struct attribute *attr,
 				char *buf)
 {
-	struct module_attribute *attribute;
+	const struct module_attribute *attribute;
 	struct module_kobject *mk;
 	int ret;
 
@@ -906,7 +906,7 @@ static ssize_t module_attr_store(struct kobject *kobj,
 				struct attribute *attr,
 				const char *buf, size_t len)
 {
-	struct module_attribute *attribute;
+	const struct module_attribute *attribute;
 	struct module_kobject *mk;
 	int ret;
 
@@ -944,10 +944,12 @@ struct kset *module_kset;
 static void module_kobj_release(struct kobject *kobj)
 {
 	struct module_kobject *mk = to_module_kobject(kobj);
-	complete(mk->kobj_completion);
+
+	if (mk->kobj_completion)
+		complete(mk->kobj_completion);
 }
 
-struct kobj_type module_ktype = {
+const struct kobj_type module_ktype = {
 	.release   =	module_kobj_release,
 	.sysfs_ops =	&module_sysfs_ops,
 };