1 files changed, 116 insertions, 26 deletions

diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c
index a44310c6a8ba..463c56545ae8 100644
--- a/drivers/firmware/efi/efivars.c
+++ b/drivers/firmware/efi/efivars.c
@@ -69,6 +69,7 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/ucs2_string.h>
+#include <linux/compat.h>
 
 #define EFIVARS_VERSION "0.08"
 #define EFIVARS_DATE "2004-May-17"
@@ -86,6 +87,15 @@ static struct kset *efivars_kset;
 static struct bin_attribute *efivars_new_var;
 static struct bin_attribute *efivars_del_var;
 
+struct compat_efi_variable {
+        efi_char16_t  VariableName[EFI_VAR_NAME_LEN/sizeof(efi_char16_t)];
+        efi_guid_t    VendorGuid;
+        __u32         DataSize;
+        __u8          Data[1024];
+        __u32         Status;
+        __u32         Attributes;
+} __packed;
+
 struct efivar_attribute {
         struct attribute attr;
         ssize_t (*show) (struct efivar_entry *entry, char *buf);
@@ -218,6 +228,25 @@ sanity_check(struct efi_variable *var, efi_char16_t *name, efi_guid_t vendor,
         return 0;
 }
 
+static inline bool is_compat(void)
+{
+        if (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())
+                return true;
+
+        return false;
+}
+
+static void
+copy_out_compat(struct efi_variable *dst, struct compat_efi_variable *src)
+{
+        memcpy(dst->VariableName, src->VariableName, EFI_VAR_NAME_LEN);
+        memcpy(dst->Data, src->Data, sizeof(src->Data));
+
+        dst->VendorGuid = src->VendorGuid;
+        dst->DataSize = src->DataSize;
+        dst->Attributes = src->Attributes;
+}
+
 /*
  * We allow each variable to be edited via rewriting the
  * entire efi variable structure.
@@ -233,22 +262,42 @@ efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
         u8 *data;
         int err;
 
-        if (count != sizeof(struct efi_variable))
-                return -EINVAL;
+        if (is_compat()) {
+                struct compat_efi_variable *compat;
 
-        new_var = (struct efi_variable *)buf;
+                if (count != sizeof(*compat))
+                        return -EINVAL;
 
-        attributes = new_var->Attributes;
-        vendor = new_var->VendorGuid;
-        name = new_var->VariableName;
-        size = new_var->DataSize;
-        data = new_var->Data;
+                compat = (struct compat_efi_variable *)buf;
+                attributes = compat->Attributes;
+                vendor = compat->VendorGuid;
+                name = compat->VariableName;
+                size = compat->DataSize;
+                data = compat->Data;
 
-        err = sanity_check(var, name, vendor, size, attributes, data);
-        if (err)
-                return err;
+                err = sanity_check(var, name, vendor, size, attributes, data);
+                if (err)
+                        return err;
+
+                copy_out_compat(&entry->var, compat);
+        } else {
+                if (count != sizeof(struct efi_variable))
+                        return -EINVAL;
+
+                new_var = (struct efi_variable *)buf;
 
-        memcpy(&entry->var, new_var, count);
+                attributes = new_var->Attributes;
+                vendor = new_var->VendorGuid;
+                name = new_var->VariableName;
+                size = new_var->DataSize;
+                data = new_var->Data;
+
+                err = sanity_check(var, name, vendor, size, attributes, data);
+                if (err)
+                        return err;
+
+                memcpy(&entry->var, new_var, count);
+        }
 
         err = efivar_entry_set(entry, attributes, size, data, NULL);
         if (err) {
@@ -263,6 +312,8 @@ static ssize_t
 efivar_show_raw(struct efivar_entry *entry, char *buf)
 {
         struct efi_variable *var = &entry->var;
+        struct compat_efi_variable *compat;
+        size_t size;
 
         if (!entry || !buf)
                 return 0;
@@ -272,9 +323,23 @@ efivar_show_raw(struct efivar_entry *entry, char *buf)
                              &entry->var.DataSize, entry->var.Data))
                 return -EIO;
 
-        memcpy(buf, var, sizeof(*var));
+        if (is_compat()) {
+                compat = (struct compat_efi_variable *)buf;
+
+                size = sizeof(*compat);
+                memcpy(compat->VariableName, var->VariableName,
+                        EFI_VAR_NAME_LEN);
+                memcpy(compat->Data, var->Data, sizeof(compat->Data));
+
+                compat->VendorGuid = var->VendorGuid;
+                compat->DataSize = var->DataSize;
+                compat->Attributes = var->Attributes;
+        } else {
+                size = sizeof(*var);
+                memcpy(buf, var, size);
+        }
 
-        return sizeof(*var);
+        return size;
 }
 
 /*
@@ -349,8 +414,10 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
                              struct bin_attribute *bin_attr,
                              char *buf, loff_t pos, size_t count)
 {
+        struct compat_efi_variable *compat = (struct compat_efi_variable *)buf;
         struct efi_variable *new_var = (struct efi_variable *)buf;
         struct efivar_entry *new_entry;
+        bool need_compat = is_compat();
         efi_char16_t *name;
         unsigned long size;
         u32 attributes;
@@ -360,13 +427,23 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
         if (!capable(CAP_SYS_ADMIN))
                 return -EACCES;
 
-        if (count != sizeof(*new_var))
-                return -EINVAL;
-
-        attributes = new_var->Attributes;
-        name = new_var->VariableName;
-        size = new_var->DataSize;
-        data = new_var->Data;
+        if (need_compat) {
+                if (count != sizeof(*compat))
+                        return -EINVAL;
+
+                attributes = compat->Attributes;
+                name = compat->VariableName;
+                size = compat->DataSize;
+                data = compat->Data;
+        } else {
+                if (count != sizeof(*new_var))
+                        return -EINVAL;
+
+                attributes = new_var->Attributes;
+                name = new_var->VariableName;
+                size = new_var->DataSize;
+                data = new_var->Data;
+        }
 
         if ((attributes & ~EFI_VARIABLE_MASK) != 0 ||
             efivar_validate(name, data, size) == false) {
@@ -378,7 +455,10 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
         if (!new_entry)
                 return -ENOMEM;
 
-        memcpy(&new_entry->var, new_var, sizeof(*new_var));
+        if (need_compat)
+                copy_out_compat(&new_entry->var, compat);
+        else
+                memcpy(&new_entry->var, new_var, sizeof(*new_var));
 
         err = efivar_entry_set(new_entry, attributes, size,
                                data, &efivar_sysfs_list);
@@ -404,6 +484,7 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
                              char *buf, loff_t pos, size_t count)
 {
         struct efi_variable *del_var = (struct efi_variable *)buf;
+        struct compat_efi_variable *compat;
         struct efivar_entry *entry;
         efi_char16_t *name;
         efi_guid_t vendor;
@@ -412,11 +493,20 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
         if (!capable(CAP_SYS_ADMIN))
                 return -EACCES;
 
-        if (count != sizeof(*del_var))
-                return -EINVAL;
+        if (is_compat()) {
+                if (count != sizeof(*compat))
+                        return -EINVAL;
+
+                compat = (struct compat_efi_variable *)buf;
+                name = compat->VariableName;
+                vendor = compat->VendorGuid;
+        } else {
+                if (count != sizeof(*del_var))
+                        return -EINVAL;
 
-        name = del_var->VariableName;
-        vendor = del_var->VendorGuid;
+                name = del_var->VariableName;
+                vendor = del_var->VendorGuid;
+        }
 
         efivar_entry_iter_begin();
         entry = efivar_entry_find(name, vendor, &efivar_sysfs_list, true);