Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 722 insertions, 0 deletions

diff --git a/fs/efivarfs/vars.c b/fs/efivarfs/vars.c
new file mode 100644
index 0000000000..9e4f47808b
--- /dev/null
+++ b/fs/efivarfs/vars.c
@@ -0,0 +1,722 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Originally from efivars.c
+ *
+ * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
+ * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
+ */
+
+#include <linux/capability.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/smp.h>
+#include <linux/efi.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/ctype.h>
+#include <linux/ucs2_string.h>
+
+#include "internal.h"
+
+MODULE_IMPORT_NS(EFIVAR);
+
+static bool
+validate_device_path(efi_char16_t *var_name, int match, u8 *buffer,
+		     unsigned long len)
+{
+	struct efi_generic_dev_path *node;
+	int offset = 0;
+
+	node = (struct efi_generic_dev_path *)buffer;
+
+	if (len < sizeof(*node))
+		return false;
+
+	while (offset <= len - sizeof(*node) &&
+	       node->length >= sizeof(*node) &&
+		node->length <= len - offset) {
+		offset += node->length;
+
+		if ((node->type == EFI_DEV_END_PATH ||
+		     node->type == EFI_DEV_END_PATH2) &&
+		    node->sub_type == EFI_DEV_END_ENTIRE)
+			return true;
+
+		node = (struct efi_generic_dev_path *)(buffer + offset);
+	}
+
+	/*
+	 * If we're here then either node->length pointed past the end
+	 * of the buffer or we reached the end of the buffer without
+	 * finding a device path end node.
+	 */
+	return false;
+}
+
+static bool
+validate_boot_order(efi_char16_t *var_name, int match, u8 *buffer,
+		    unsigned long len)
+{
+	/* An array of 16-bit integers */
+	if ((len % 2) != 0)
+		return false;
+
+	return true;
+}
+
+static bool
+validate_load_option(efi_char16_t *var_name, int match, u8 *buffer,
+		     unsigned long len)
+{
+	u16 filepathlength;
+	int i, desclength = 0, namelen;
+
+	namelen = ucs2_strnlen(var_name, EFI_VAR_NAME_LEN);
+
+	/* Either "Boot" or "Driver" followed by four digits of hex */
+	for (i = match; i < match+4; i++) {
+		if (var_name[i] > 127 ||
+		    hex_to_bin(var_name[i] & 0xff) < 0)
+			return true;
+	}
+
+	/* Reject it if there's 4 digits of hex and then further content */
+	if (namelen > match + 4)
+		return false;
+
+	/* A valid entry must be at least 8 bytes */
+	if (len < 8)
+		return false;
+
+	filepathlength = buffer[4] | buffer[5] << 8;
+
+	/*
+	 * There's no stored length for the description, so it has to be
+	 * found by hand
+	 */
+	desclength = ucs2_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2;
+
+	/* Each boot entry must have a descriptor */
+	if (!desclength)
+		return false;
+
+	/*
+	 * If the sum of the length of the description, the claimed filepath
+	 * length and the original header are greater than the length of the
+	 * variable, it's malformed
+	 */
+	if ((desclength + filepathlength + 6) > len)
+		return false;
+
+	/*
+	 * And, finally, check the filepath
+	 */
+	return validate_device_path(var_name, match, buffer + desclength + 6,
+				    filepathlength);
+}
+
+static bool
+validate_uint16(efi_char16_t *var_name, int match, u8 *buffer,
+		unsigned long len)
+{
+	/* A single 16-bit integer */
+	if (len != 2)
+		return false;
+
+	return true;
+}
+
+static bool
+validate_ascii_string(efi_char16_t *var_name, int match, u8 *buffer,
+		      unsigned long len)
+{
+	int i;
+
+	for (i = 0; i < len; i++) {
+		if (buffer[i] > 127)
+			return false;
+
+		if (buffer[i] == 0)
+			return true;
+	}
+
+	return false;
+}
+
+struct variable_validate {
+	efi_guid_t vendor;
+	char *name;
+	bool (*validate)(efi_char16_t *var_name, int match, u8 *data,
+			 unsigned long len);
+};
+
+/*
+ * This is the list of variables we need to validate, as well as the
+ * whitelist for what we think is safe not to default to immutable.
+ *
+ * If it has a validate() method that's not NULL, it'll go into the
+ * validation routine.  If not, it is assumed valid, but still used for
+ * whitelisting.
+ *
+ * Note that it's sorted by {vendor,name}, but globbed names must come after
+ * any other name with the same prefix.
+ */
+static const struct variable_validate variable_validate[] = {
+	{ EFI_GLOBAL_VARIABLE_GUID, "BootNext", validate_uint16 },
+	{ EFI_GLOBAL_VARIABLE_GUID, "BootOrder", validate_boot_order },
+	{ EFI_GLOBAL_VARIABLE_GUID, "Boot*", validate_load_option },
+	{ EFI_GLOBAL_VARIABLE_GUID, "DriverOrder", validate_boot_order },
+	{ EFI_GLOBAL_VARIABLE_GUID, "Driver*", validate_load_option },
+	{ EFI_GLOBAL_VARIABLE_GUID, "ConIn", validate_device_path },
+	{ EFI_GLOBAL_VARIABLE_GUID, "ConInDev", validate_device_path },
+	{ EFI_GLOBAL_VARIABLE_GUID, "ConOut", validate_device_path },
+	{ EFI_GLOBAL_VARIABLE_GUID, "ConOutDev", validate_device_path },
+	{ EFI_GLOBAL_VARIABLE_GUID, "ErrOut", validate_device_path },
+	{ EFI_GLOBAL_VARIABLE_GUID, "ErrOutDev", validate_device_path },
+	{ EFI_GLOBAL_VARIABLE_GUID, "Lang", validate_ascii_string },
+	{ EFI_GLOBAL_VARIABLE_GUID, "OsIndications", NULL },
+	{ EFI_GLOBAL_VARIABLE_GUID, "PlatformLang", validate_ascii_string },
+	{ EFI_GLOBAL_VARIABLE_GUID, "Timeout", validate_uint16 },
+	{ LINUX_EFI_CRASH_GUID, "*", NULL },
+	{ NULL_GUID, "", NULL },
+};
+
+/*
+ * Check if @var_name matches the pattern given in @match_name.
+ *
+ * @var_name: an array of @len non-NUL characters.
+ * @match_name: a NUL-terminated pattern string, optionally ending in "*". A
+ *              final "*" character matches any trailing characters @var_name,
+ *              including the case when there are none left in @var_name.
+ * @match: on output, the number of non-wildcard characters in @match_name
+ *         that @var_name matches, regardless of the return value.
+ * @return: whether @var_name fully matches @match_name.
+ */
+static bool
+variable_matches(const char *var_name, size_t len, const char *match_name,
+		 int *match)
+{
+	for (*match = 0; ; (*match)++) {
+		char c = match_name[*match];
+
+		switch (c) {
+		case '*':
+			/* Wildcard in @match_name means we've matched. */
+			return true;
+
+		case '\0':
+			/* @match_name has ended. Has @var_name too? */
+			return (*match == len);
+
+		default:
+			/*
+			 * We've reached a non-wildcard char in @match_name.
+			 * Continue only if there's an identical character in
+			 * @var_name.
+			 */
+			if (*match < len && c == var_name[*match])
+				continue;
+			return false;
+		}
+	}
+}
+
+bool
+efivar_validate(efi_guid_t vendor, efi_char16_t *var_name, u8 *data,
+		unsigned long data_size)
+{
+	int i;
+	unsigned long utf8_size;
+	u8 *utf8_name;
+
+	utf8_size = ucs2_utf8size(var_name);
+	utf8_name = kmalloc(utf8_size + 1, GFP_KERNEL);
+	if (!utf8_name)
+		return false;
+
+	ucs2_as_utf8(utf8_name, var_name, utf8_size);
+	utf8_name[utf8_size] = '\0';
+
+	for (i = 0; variable_validate[i].name[0] != '\0'; i++) {
+		const char *name = variable_validate[i].name;
+		int match = 0;
+
+		if (efi_guidcmp(vendor, variable_validate[i].vendor))
+			continue;
+
+		if (variable_matches(utf8_name, utf8_size+1, name, &match)) {
+			if (variable_validate[i].validate == NULL)
+				break;
+			kfree(utf8_name);
+			return variable_validate[i].validate(var_name, match,
+							     data, data_size);
+		}
+	}
+	kfree(utf8_name);
+	return true;
+}
+
+bool
+efivar_variable_is_removable(efi_guid_t vendor, const char *var_name,
+			     size_t len)
+{
+	int i;
+	bool found = false;
+	int match = 0;
+
+	/*
+	 * Check if our variable is in the validated variables list
+	 */
+	for (i = 0; variable_validate[i].name[0] != '\0'; i++) {
+		if (efi_guidcmp(variable_validate[i].vendor, vendor))
+			continue;
+
+		if (variable_matches(var_name, len,
+				     variable_validate[i].name, &match)) {
+			found = true;
+			break;
+		}
+	}
+
+	/*
+	 * If it's in our list, it is removable.
+	 */
+	return found;
+}
+
+static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor,
+				struct list_head *head)
+{
+	struct efivar_entry *entry, *n;
+	unsigned long strsize1, strsize2;
+	bool found = false;
+
+	strsize1 = ucs2_strsize(variable_name, 1024);
+	list_for_each_entry_safe(entry, n, head, list) {
+		strsize2 = ucs2_strsize(entry->var.VariableName, 1024);
+		if (strsize1 == strsize2 &&
+			!memcmp(variable_name, &(entry->var.VariableName),
+				strsize2) &&
+			!efi_guidcmp(entry->var.VendorGuid,
+				*vendor)) {
+			found = true;
+			break;
+		}
+	}
+	return found;
+}
+
+/*
+ * Returns the size of variable_name, in bytes, including the
+ * terminating NULL character, or variable_name_size if no NULL
+ * character is found among the first variable_name_size bytes.
+ */
+static unsigned long var_name_strnsize(efi_char16_t *variable_name,
+				       unsigned long variable_name_size)
+{
+	unsigned long len;
+	efi_char16_t c;
+
+	/*
+	 * The variable name is, by definition, a NULL-terminated
+	 * string, so make absolutely sure that variable_name_size is
+	 * the value we expect it to be. If not, return the real size.
+	 */
+	for (len = 2; len <= variable_name_size; len += sizeof(c)) {
+		c = variable_name[(len / sizeof(c)) - 1];
+		if (!c)
+			break;
+	}
+
+	return min(len, variable_name_size);
+}
+
+/*
+ * Print a warning when duplicate EFI variables are encountered and
+ * disable the sysfs workqueue since the firmware is buggy.
+ */
+static void dup_variable_bug(efi_char16_t *str16, efi_guid_t *vendor_guid,
+			     unsigned long len16)
+{
+	size_t i, len8 = len16 / sizeof(efi_char16_t);
+	char *str8;
+
+	str8 = kzalloc(len8, GFP_KERNEL);
+	if (!str8)
+		return;
+
+	for (i = 0; i < len8; i++)
+		str8[i] = str16[i];
+
+	printk(KERN_WARNING "efivars: duplicate variable: %s-%pUl\n",
+	       str8, vendor_guid);
+	kfree(str8);
+}
+
+/**
+ * efivar_init - build the initial list of EFI variables
+ * @func: callback function to invoke for every variable
+ * @data: function-specific data to pass to @func
+ * @duplicates: error if we encounter duplicates on @head?
+ * @head: initialised head of variable list
+ *
+ * Get every EFI variable from the firmware and invoke @func. @func
+ * should call efivar_entry_add() to build the list of variables.
+ *
+ * Returns 0 on success, or a kernel error code on failure.
+ */
+int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
+		void *data, bool duplicates, struct list_head *head)
+{
+	unsigned long variable_name_size = 1024;
+	efi_char16_t *variable_name;
+	efi_status_t status;
+	efi_guid_t vendor_guid;
+	int err = 0;
+
+	variable_name = kzalloc(variable_name_size, GFP_KERNEL);
+	if (!variable_name) {
+		printk(KERN_ERR "efivars: Memory allocation failed.\n");
+		return -ENOMEM;
+	}
+
+	err = efivar_lock();
+	if (err)
+		goto free;
+
+	/*
+	 * Per EFI spec, the maximum storage allocated for both
+	 * the variable name and variable data is 1024 bytes.
+	 */
+
+	do {
+		variable_name_size = 1024;
+
+		status = efivar_get_next_variable(&variable_name_size,
+						  variable_name,
+						  &vendor_guid);
+		switch (status) {
+		case EFI_SUCCESS:
+			variable_name_size = var_name_strnsize(variable_name,
+							       variable_name_size);
+
+			/*
+			 * Some firmware implementations return the
+			 * same variable name on multiple calls to
+			 * get_next_variable(). Terminate the loop
+			 * immediately as there is no guarantee that
+			 * we'll ever see a different variable name,
+			 * and may end up looping here forever.
+			 */
+			if (duplicates &&
+			    variable_is_present(variable_name, &vendor_guid,
+						head)) {
+				dup_variable_bug(variable_name, &vendor_guid,
+						 variable_name_size);
+				status = EFI_NOT_FOUND;
+			} else {
+				err = func(variable_name, vendor_guid,
+					   variable_name_size, data);
+				if (err)
+					status = EFI_NOT_FOUND;
+			}
+			break;
+		case EFI_UNSUPPORTED:
+			err = -EOPNOTSUPP;
+			status = EFI_NOT_FOUND;
+			break;
+		case EFI_NOT_FOUND:
+			break;
+		default:
+			printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
+				status);
+			status = EFI_NOT_FOUND;
+			break;
+		}
+
+	} while (status != EFI_NOT_FOUND);
+
+	efivar_unlock();
+free:
+	kfree(variable_name);
+
+	return err;
+}
+
+/**
+ * efivar_entry_add - add entry to variable list
+ * @entry: entry to add to list
+ * @head: list head
+ *
+ * Returns 0 on success, or a kernel error code on failure.
+ */
+int efivar_entry_add(struct efivar_entry *entry, struct list_head *head)
+{
+	int err;
+
+	err = efivar_lock();
+	if (err)
+		return err;
+	list_add(&entry->list, head);
+	efivar_unlock();
+
+	return 0;
+}
+
+/**
+ * __efivar_entry_add - add entry to variable list
+ * @entry: entry to add to list
+ * @head: list head
+ */
+void __efivar_entry_add(struct efivar_entry *entry, struct list_head *head)
+{
+	list_add(&entry->list, head);
+}
+
+/**
+ * efivar_entry_remove - remove entry from variable list
+ * @entry: entry to remove from list
+ *
+ * Returns 0 on success, or a kernel error code on failure.
+ */
+void efivar_entry_remove(struct efivar_entry *entry)
+{
+	list_del(&entry->list);
+}
+
+/*
+ * efivar_entry_list_del_unlock - remove entry from variable list
+ * @entry: entry to remove
+ *
+ * Remove @entry from the variable list and release the list lock.
+ *
+ * NOTE: slightly weird locking semantics here - we expect to be
+ * called with the efivars lock already held, and we release it before
+ * returning. This is because this function is usually called after
+ * set_variable() while the lock is still held.
+ */
+static void efivar_entry_list_del_unlock(struct efivar_entry *entry)
+{
+	list_del(&entry->list);
+	efivar_unlock();
+}
+
+/**
+ * efivar_entry_delete - delete variable and remove entry from list
+ * @entry: entry containing variable to delete
+ *
+ * Delete the variable from the firmware and remove @entry from the
+ * variable list. It is the caller's responsibility to free @entry
+ * once we return.
+ *
+ * Returns 0 on success, -EINTR if we can't grab the semaphore,
+ * converted EFI status code if set_variable() fails.
+ */
+int efivar_entry_delete(struct efivar_entry *entry)
+{
+	efi_status_t status;
+	int err;
+
+	err = efivar_lock();
+	if (err)
+		return err;
+
+	status = efivar_set_variable_locked(entry->var.VariableName,
+					    &entry->var.VendorGuid,
+					    0, 0, NULL, false);
+	if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND)) {
+		efivar_unlock();
+		return efi_status_to_err(status);
+	}
+
+	efivar_entry_list_del_unlock(entry);
+	return 0;
+}
+
+/**
+ * efivar_entry_size - obtain the size of a variable
+ * @entry: entry for this variable
+ * @size: location to store the variable's size
+ */
+int efivar_entry_size(struct efivar_entry *entry, unsigned long *size)
+{
+	efi_status_t status;
+	int err;
+
+	*size = 0;
+
+	err = efivar_lock();
+	if (err)
+		return err;
+
+	status = efivar_get_variable(entry->var.VariableName,
+				     &entry->var.VendorGuid, NULL, size, NULL);
+	efivar_unlock();
+
+	if (status != EFI_BUFFER_TOO_SMALL)
+		return efi_status_to_err(status);
+
+	return 0;
+}
+
+/**
+ * __efivar_entry_get - call get_variable()
+ * @entry: read data for this variable
+ * @attributes: variable attributes
+ * @size: size of @data buffer
+ * @data: buffer to store variable data
+ *
+ * The caller MUST call efivar_entry_iter_begin() and
+ * efivar_entry_iter_end() before and after the invocation of this
+ * function, respectively.
+ */
+int __efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
+		       unsigned long *size, void *data)
+{
+	efi_status_t status;
+
+	status = efivar_get_variable(entry->var.VariableName,
+				     &entry->var.VendorGuid,
+				     attributes, size, data);
+
+	return efi_status_to_err(status);
+}
+
+/**
+ * efivar_entry_get - call get_variable()
+ * @entry: read data for this variable
+ * @attributes: variable attributes
+ * @size: size of @data buffer
+ * @data: buffer to store variable data
+ */
+int efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
+		     unsigned long *size, void *data)
+{
+	int err;
+
+	err = efivar_lock();
+	if (err)
+		return err;
+	err = __efivar_entry_get(entry, attributes, size, data);
+	efivar_unlock();
+
+	return 0;
+}
+
+/**
+ * efivar_entry_set_get_size - call set_variable() and get new size (atomic)
+ * @entry: entry containing variable to set and get
+ * @attributes: attributes of variable to be written
+ * @size: size of data buffer
+ * @data: buffer containing data to write
+ * @set: did the set_variable() call succeed?
+ *
+ * This is a pretty special (complex) function. See efivarfs_file_write().
+ *
+ * Atomically call set_variable() for @entry and if the call is
+ * successful, return the new size of the variable from get_variable()
+ * in @size. The success of set_variable() is indicated by @set.
+ *
+ * Returns 0 on success, -EINVAL if the variable data is invalid,
+ * -ENOSPC if the firmware does not have enough available space, or a
+ * converted EFI status code if either of set_variable() or
+ * get_variable() fail.
+ *
+ * If the EFI variable does not exist when calling set_variable()
+ * (EFI_NOT_FOUND), @entry is removed from the variable list.
+ */
+int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,
+			      unsigned long *size, void *data, bool *set)
+{
+	efi_char16_t *name = entry->var.VariableName;
+	efi_guid_t *vendor = &entry->var.VendorGuid;
+	efi_status_t status;
+	int err;
+
+	*set = false;
+
+	if (efivar_validate(*vendor, name, data, *size) == false)
+		return -EINVAL;
+
+	/*
+	 * The lock here protects the get_variable call, the conditional
+	 * set_variable call, and removal of the variable from the efivars
+	 * list (in the case of an authenticated delete).
+	 */
+	err = efivar_lock();
+	if (err)
+		return err;
+
+	status = efivar_set_variable_locked(name, vendor, attributes, *size,
+					    data, false);
+	if (status != EFI_SUCCESS) {
+		err = efi_status_to_err(status);
+		goto out;
+	}
+
+	*set = true;
+
+	/*
+	 * Writing to the variable may have caused a change in size (which
+	 * could either be an append or an overwrite), or the variable to be
+	 * deleted. Perform a GetVariable() so we can tell what actually
+	 * happened.
+	 */
+	*size = 0;
+	status = efivar_get_variable(entry->var.VariableName,
+				    &entry->var.VendorGuid,
+				    NULL, size, NULL);
+
+	if (status == EFI_NOT_FOUND)
+		efivar_entry_list_del_unlock(entry);
+	else
+		efivar_unlock();
+
+	if (status && status != EFI_BUFFER_TOO_SMALL)
+		return efi_status_to_err(status);
+
+	return 0;
+
+out:
+	efivar_unlock();
+	return err;
+
+}
+
+/**
+ * efivar_entry_iter - iterate over variable list
+ * @func: callback function
+ * @head: head of variable list
+ * @data: function-specific data to pass to callback
+ *
+ * Iterate over the list of EFI variables and call @func with every
+ * entry on the list. It is safe for @func to remove entries in the
+ * list via efivar_entry_delete() while iterating.
+ *
+ * Some notes for the callback function:
+ *  - a non-zero return value indicates an error and terminates the loop
+ *  - @func is called from atomic context
+ */
+int efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
+		      struct list_head *head, void *data)
+{
+	struct efivar_entry *entry, *n;
+	int err = 0;
+
+	err = efivar_lock();
+	if (err)
+		return err;
+
+	list_for_each_entry_safe(entry, n, head, list) {
+		err = func(entry, data);
+		if (err)
+			break;
+	}
+	efivar_unlock();
+
+	return err;
+}