From 5d9db883761ad1bc2245fd3018715549b974203d Mon Sep 17 00:00:00 2001 From: Matthew Garrett Date: Fri, 5 Oct 2012 13:54:56 +0800 Subject: efi: Add support for a UEFI variable filesystem The existing EFI variables code only supports variables of up to 1024 bytes. This limitation existed in version 0.99 of the EFI specification, but was removed before any full releases. Since variables can now be larger than a single page, sysfs isn't the best interface for this. So, instead, let's add a filesystem. Variables can be read, written and created, with the first 4 bytes of each variable representing its UEFI attributes. The create() method doesn't actually commit to flash since zero-length variables can't exist per-spec. Updates from Jeremy Kerr . Signed-off-by: Matthew Garrett Signed-off-by: Jeremy Kerr Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 384 ++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 378 insertions(+), 6 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index d10c9873dd9..b605c484977 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -80,6 +80,10 @@ #include #include +#include +#include +#include + #include #define EFIVARS_VERSION "0.08" @@ -91,6 +95,7 @@ MODULE_LICENSE("GPL"); MODULE_VERSION(EFIVARS_VERSION); #define DUMP_NAME_LEN 52 +#define GUID_LEN 37 /* * The maximum size of VariableName + Data = 1024 @@ -108,7 +113,6 @@ struct efi_variable { __u32 Attributes; } __attribute__((packed)); - struct efivar_entry { struct efivars *efivars; struct efi_variable var; @@ -122,6 +126,9 @@ struct efivar_attribute { ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count); }; +static struct efivars __efivars; +static struct efivar_operations ops; + #define PSTORE_EFI_ATTRIBUTES \ (EFI_VARIABLE_NON_VOLATILE | \ EFI_VARIABLE_BOOTSERVICE_ACCESS | \ @@ -629,14 +636,380 @@ static struct kobj_type efivar_ktype = { .default_attrs = def_attrs, }; -static struct pstore_info efi_pstore_info; - static inline void efivar_unregister(struct efivar_entry *var) { kobject_put(&var->kobj); } +static int efivarfs_file_open(struct inode *inode, struct file *file) +{ + file->private_data = inode->i_private; + return 0; +} + +static ssize_t efivarfs_file_write(struct file *file, + const char __user *userbuf, size_t count, loff_t *ppos) +{ + struct efivar_entry *var = file->private_data; + struct efivars *efivars; + efi_status_t status; + void *data; + u32 attributes; + struct inode *inode = file->f_mapping->host; + int datasize = count - sizeof(attributes); + + if (count < sizeof(attributes)) + return -EINVAL; + + data = kmalloc(datasize, GFP_KERNEL); + + if (!data) + return -ENOMEM; + + efivars = var->efivars; + + if (copy_from_user(&attributes, userbuf, sizeof(attributes))) { + count = -EFAULT; + goto out; + } + + if (attributes & ~(EFI_VARIABLE_MASK)) { + count = -EINVAL; + goto out; + } + + if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) { + count = -EFAULT; + goto out; + } + + if (validate_var(&var->var, data, datasize) == false) { + count = -EINVAL; + goto out; + } + + status = efivars->ops->set_variable(var->var.VariableName, + &var->var.VendorGuid, + attributes, datasize, + data); + + switch (status) { + case EFI_SUCCESS: + mutex_lock(&inode->i_mutex); + i_size_write(inode, count); + mutex_unlock(&inode->i_mutex); + break; + case EFI_INVALID_PARAMETER: + count = -EINVAL; + break; + case EFI_OUT_OF_RESOURCES: + count = -ENOSPC; + break; + case EFI_DEVICE_ERROR: + count = -EIO; + break; + case EFI_WRITE_PROTECTED: + count = -EROFS; + break; + case EFI_SECURITY_VIOLATION: + count = -EACCES; + break; + case EFI_NOT_FOUND: + count = -ENOENT; + break; + default: + count = -EINVAL; + break; + } +out: + kfree(data); + + return count; +} + +static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, + size_t count, loff_t *ppos) +{ + struct efivar_entry *var = file->private_data; + struct efivars *efivars = var->efivars; + efi_status_t status; + unsigned long datasize = 0; + u32 attributes; + void *data; + ssize_t size; + + status = efivars->ops->get_variable(var->var.VariableName, + &var->var.VendorGuid, + &attributes, &datasize, NULL); + + if (status != EFI_BUFFER_TOO_SMALL) + return 0; + + data = kmalloc(datasize + 4, GFP_KERNEL); + + if (!data) + return 0; + + status = efivars->ops->get_variable(var->var.VariableName, + &var->var.VendorGuid, + &attributes, &datasize, + (data + 4)); + + if (status != EFI_SUCCESS) + return 0; + + memcpy(data, &attributes, 4); + size = simple_read_from_buffer(userbuf, count, ppos, + data, datasize + 4); + kfree(data); + + return size; +} + +static void efivarfs_evict_inode(struct inode *inode) +{ + clear_inode(inode); +} + +static const struct super_operations efivarfs_ops = { + .statfs = simple_statfs, + .drop_inode = generic_delete_inode, + .evict_inode = efivarfs_evict_inode, + .show_options = generic_show_options, +}; + +static struct super_block *efivarfs_sb; + +static const struct inode_operations efivarfs_dir_inode_operations; + +static const struct file_operations efivarfs_file_operations = { + .open = efivarfs_file_open, + .read = efivarfs_file_read, + .write = efivarfs_file_write, + .llseek = no_llseek, +}; + +static struct inode *efivarfs_get_inode(struct super_block *sb, + const struct inode *dir, int mode, dev_t dev) +{ + struct inode *inode = new_inode(sb); + + if (inode) { + inode->i_ino = get_next_ino(); + inode->i_uid = inode->i_gid = 0; + inode->i_mode = mode; + inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; + switch (mode & S_IFMT) { + case S_IFREG: + inode->i_fop = &efivarfs_file_operations; + break; + case S_IFDIR: + inode->i_op = &efivarfs_dir_inode_operations; + inode->i_fop = &simple_dir_operations; + inc_nlink(inode); + break; + } + } + return inode; +} + +static void efivarfs_hex_to_guid(const char *str, efi_guid_t *guid) +{ + guid->b[0] = hex_to_bin(str[6]) << 4 | hex_to_bin(str[7]); + guid->b[1] = hex_to_bin(str[4]) << 4 | hex_to_bin(str[5]); + guid->b[2] = hex_to_bin(str[2]) << 4 | hex_to_bin(str[3]); + guid->b[3] = hex_to_bin(str[0]) << 4 | hex_to_bin(str[1]); + guid->b[4] = hex_to_bin(str[11]) << 4 | hex_to_bin(str[12]); + guid->b[5] = hex_to_bin(str[9]) << 4 | hex_to_bin(str[10]); + guid->b[6] = hex_to_bin(str[16]) << 4 | hex_to_bin(str[17]); + guid->b[7] = hex_to_bin(str[14]) << 4 | hex_to_bin(str[15]); + guid->b[8] = hex_to_bin(str[19]) << 4 | hex_to_bin(str[20]); + guid->b[9] = hex_to_bin(str[21]) << 4 | hex_to_bin(str[22]); + guid->b[10] = hex_to_bin(str[24]) << 4 | hex_to_bin(str[25]); + guid->b[11] = hex_to_bin(str[26]) << 4 | hex_to_bin(str[27]); + guid->b[12] = hex_to_bin(str[28]) << 4 | hex_to_bin(str[29]); + guid->b[13] = hex_to_bin(str[30]) << 4 | hex_to_bin(str[31]); + guid->b[14] = hex_to_bin(str[32]) << 4 | hex_to_bin(str[33]); + guid->b[15] = hex_to_bin(str[34]) << 4 | hex_to_bin(str[35]); +} + +static int efivarfs_create(struct inode *dir, struct dentry *dentry, + umode_t mode, bool excl) +{ + struct inode *inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0); + struct efivars *efivars = &__efivars; + struct efivar_entry *var; + int namelen, i = 0, err = 0; + + if (dentry->d_name.len < 38) + return -EINVAL; + + if (!inode) + return -ENOSPC; + + var = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL); + + if (!var) + return -ENOMEM; + + namelen = dentry->d_name.len - GUID_LEN; + + efivarfs_hex_to_guid(dentry->d_name.name + namelen + 1, + &var->var.VendorGuid); + + for (i = 0; i < namelen; i++) + var->var.VariableName[i] = dentry->d_name.name[i]; + + var->var.VariableName[i] = '\0'; + + inode->i_private = var; + var->efivars = efivars; + var->kobj.kset = efivars->kset; + + err = kobject_init_and_add(&var->kobj, &efivar_ktype, NULL, "%s", + dentry->d_name.name); + if (err) + goto out; + + kobject_uevent(&var->kobj, KOBJ_ADD); + spin_lock(&efivars->lock); + list_add(&var->list, &efivars->list); + spin_unlock(&efivars->lock); + d_instantiate(dentry, inode); + dget(dentry); +out: + if (err) + kfree(var); + return err; +} + +static int efivarfs_unlink(struct inode *dir, struct dentry *dentry) +{ + struct efivar_entry *var = dentry->d_inode->i_private; + struct efivars *efivars = var->efivars; + efi_status_t status; + + spin_lock(&efivars->lock); + + status = efivars->ops->set_variable(var->var.VariableName, + &var->var.VendorGuid, + 0, 0, NULL); + + if (status == EFI_SUCCESS || status == EFI_NOT_FOUND) { + list_del(&var->list); + spin_unlock(&efivars->lock); + efivar_unregister(var); + drop_nlink(dir); + dput(dentry); + return 0; + } + + spin_unlock(&efivars->lock); + return -EINVAL; +}; + +int efivarfs_fill_super(struct super_block *sb, void *data, int silent) +{ + struct inode *inode = NULL; + struct dentry *root; + struct efivar_entry *entry, *n; + struct efivars *efivars = &__efivars; + int err; + + efivarfs_sb = sb; + + sb->s_maxbytes = MAX_LFS_FILESIZE; + sb->s_blocksize = PAGE_CACHE_SIZE; + sb->s_blocksize_bits = PAGE_CACHE_SHIFT; + sb->s_magic = PSTOREFS_MAGIC; + sb->s_op = &efivarfs_ops; + sb->s_time_gran = 1; + + inode = efivarfs_get_inode(sb, NULL, S_IFDIR | 0755, 0); + if (!inode) { + err = -ENOMEM; + goto fail; + } + inode->i_op = &efivarfs_dir_inode_operations; + + root = d_make_root(inode); + sb->s_root = root; + if (!root) { + err = -ENOMEM; + goto fail; + } + + list_for_each_entry_safe(entry, n, &efivars->list, list) { + struct inode *inode; + struct dentry *dentry, *root = efivarfs_sb->s_root; + char *name; + unsigned long size = 0; + int len, i; + + len = utf16_strlen(entry->var.VariableName); + + /* GUID plus trailing NULL */ + name = kmalloc(len + 38, GFP_ATOMIC); + + for (i = 0; i < len; i++) + name[i] = entry->var.VariableName[i] & 0xFF; + + name[len] = '-'; + + efi_guid_unparse(&entry->var.VendorGuid, name + len + 1); + + name[len+GUID_LEN] = '\0'; + + inode = efivarfs_get_inode(efivarfs_sb, root->d_inode, + S_IFREG | 0644, 0); + dentry = d_alloc_name(root, name); + + efivars->ops->get_variable(entry->var.VariableName, + &entry->var.VendorGuid, + &entry->var.Attributes, + &size, + NULL); + + mutex_lock(&inode->i_mutex); + inode->i_private = entry; + i_size_write(inode, size+4); + mutex_unlock(&inode->i_mutex); + d_add(dentry, inode); + } + + return 0; +fail: + iput(inode); + return err; +} + +static struct dentry *efivarfs_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *data) +{ + return mount_single(fs_type, flags, data, efivarfs_fill_super); +} + +static void efivarfs_kill_sb(struct super_block *sb) +{ + kill_litter_super(sb); + efivarfs_sb = NULL; +} + +static struct file_system_type efivarfs_type = { + .name = "efivarfs", + .mount = efivarfs_mount, + .kill_sb = efivarfs_kill_sb, +}; + +static const struct inode_operations efivarfs_dir_inode_operations = { + .lookup = simple_lookup, + .unlink = efivarfs_unlink, + .create = efivarfs_create, +}; + +static struct pstore_info efi_pstore_info; + #ifdef CONFIG_PSTORE static int efi_pstore_open(struct pstore_info *psi) @@ -1198,6 +1571,8 @@ int register_efivars(struct efivars *efivars, pstore_register(&efivars->efi_pstore_info); } + register_filesystem(&efivarfs_type); + out: kfree(variable_name); @@ -1205,9 +1580,6 @@ out: } EXPORT_SYMBOL_GPL(register_efivars); -static struct efivars __efivars; -static struct efivar_operations ops; - /* * For now we register the efi subsystem with the firmware subsystem * and the vars subsystem with the efi subsystem. In the future, it -- cgit v1.2.3 From 0c542edde3cecc99b180a440ae33dcb7f28642ce Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Fri, 5 Oct 2012 13:54:56 +0800 Subject: efi: Handle deletions and size changes in efivarfs_write_file A write to an efivarfs file will not always result in a variable of 'count' size after the EFI SetVariable() call. We may have appended to the existing data (ie, with the EFI_VARIABLE_APPEND_WRITE attribute), or even have deleted the variable (with an authenticated variable update, with a zero datasize). This change re-reads the updated variable from firmware, to check for size changes and deletions. In the latter case, we need to drop the dentry. Signed-off-by: Jeremy Kerr Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 49 ++++++++++++++++++++++++++++++++++++---------- 1 file changed, 39 insertions(+), 10 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index b605c484977..d7658b4a501 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -658,6 +658,7 @@ static ssize_t efivarfs_file_write(struct file *file, u32 attributes; struct inode *inode = file->f_mapping->host; int datasize = count - sizeof(attributes); + unsigned long newdatasize; if (count < sizeof(attributes)) return -EINVAL; @@ -696,32 +697,60 @@ static ssize_t efivarfs_file_write(struct file *file, switch (status) { case EFI_SUCCESS: - mutex_lock(&inode->i_mutex); - i_size_write(inode, count); - mutex_unlock(&inode->i_mutex); break; case EFI_INVALID_PARAMETER: count = -EINVAL; - break; + goto out; case EFI_OUT_OF_RESOURCES: count = -ENOSPC; - break; + goto out; case EFI_DEVICE_ERROR: count = -EIO; - break; + goto out; case EFI_WRITE_PROTECTED: count = -EROFS; - break; + goto out; case EFI_SECURITY_VIOLATION: count = -EACCES; - break; + goto out; case EFI_NOT_FOUND: count = -ENOENT; - break; + goto out; default: count = -EINVAL; - break; + goto out; } + + /* + * 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. + */ + newdatasize = 0; + status = efivars->ops->get_variable(var->var.VariableName, + &var->var.VendorGuid, + NULL, &newdatasize, + NULL); + + if (status == EFI_BUFFER_TOO_SMALL) { + mutex_lock(&inode->i_mutex); + i_size_write(inode, newdatasize + sizeof(attributes)); + mutex_unlock(&inode->i_mutex); + + } else if (status == EFI_NOT_FOUND) { + spin_lock(&efivars->lock); + list_del(&var->list); + spin_unlock(&efivars->lock); + efivar_unregister(var); + drop_nlink(inode); + dput(file->f_dentry); + + } else { + pr_warn("efivarfs: inconsistent EFI variable implementation? " + "status = %lx\n", status); + } + out: kfree(data); -- cgit v1.2.3 From 605e70c7aa1b7b0d554baf945630c1d606bbfbc3 Mon Sep 17 00:00:00 2001 From: "Lee, Chun-Yi" Date: Fri, 5 Oct 2012 13:54:56 +0800 Subject: efi: add efivars kobject to efi sysfs folder UEFI variable filesystem need a new mount point, so this patch add efivars kobject to efi_kobj for create a /sys/firmware/efi/efivars folder. Cc: Matthew Garrett Cc: H. Peter Anvin Signed-off-by: Lee, Chun-Yi Signed-off-by: Jeremy Kerr Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index d7658b4a501..6793965b7c8 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -1527,6 +1527,7 @@ void unregister_efivars(struct efivars *efivars) sysfs_remove_bin_file(&efivars->kset->kobj, efivars->del_var); kfree(efivars->new_var); kfree(efivars->del_var); + kobject_put(efivars->kobject); kset_unregister(efivars->kset); } EXPORT_SYMBOL_GPL(unregister_efivars); @@ -1558,6 +1559,14 @@ int register_efivars(struct efivars *efivars, goto out; } + efivars->kobject = kobject_create_and_add("efivars", parent_kobj); + if (!efivars->kobject) { + pr_err("efivars: Subsystem registration failed.\n"); + error = -ENOMEM; + kset_unregister(efivars->kset); + goto out; + } + /* * Per EFI spec, the maximum storage allocated for both * the variable name and variable data is 1024 bytes. -- cgit v1.2.3 From d142df03a798ee7d2db10a1f20945110ea6067ff Mon Sep 17 00:00:00 2001 From: Andy Whitcroft Date: Thu, 11 Oct 2012 11:32:17 +0100 Subject: efivarfs: efivarfs_file_read ensure we free data in error paths Signed-off-by: Andy Whitcroft Acked-by: Matthew Garrett Acked-by: Jeremy Kerr Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 6793965b7c8..b7c9a3261dc 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -766,7 +766,7 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, unsigned long datasize = 0; u32 attributes; void *data; - ssize_t size; + ssize_t size = 0; status = efivars->ops->get_variable(var->var.VariableName, &var->var.VendorGuid, @@ -784,13 +784,13 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, &var->var.VendorGuid, &attributes, &datasize, (data + 4)); - if (status != EFI_SUCCESS) - return 0; + goto out_free; memcpy(data, &attributes, 4); size = simple_read_from_buffer(userbuf, count, ppos, data, datasize + 4); +out_free: kfree(data); return size; -- cgit v1.2.3 From 45a937a883c4411648b80e87341b237cc48009c1 Mon Sep 17 00:00:00 2001 From: Andy Whitcroft Date: Thu, 11 Oct 2012 11:32:18 +0100 Subject: efivarfs: efivarfs_create() ensure we drop our reference on inode on error Signed-off-by: Andy Whitcroft Acked-by: Matthew Garrett Acked-by: Jeremy Kerr Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index b7c9a3261dc..6e5f367145f 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -866,7 +866,7 @@ static void efivarfs_hex_to_guid(const char *str, efi_guid_t *guid) static int efivarfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl) { - struct inode *inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0); + struct inode *inode; struct efivars *efivars = &__efivars; struct efivar_entry *var; int namelen, i = 0, err = 0; @@ -874,13 +874,15 @@ static int efivarfs_create(struct inode *dir, struct dentry *dentry, if (dentry->d_name.len < 38) return -EINVAL; + inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0); if (!inode) return -ENOSPC; var = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL); - - if (!var) - return -ENOMEM; + if (!var) { + err = -ENOMEM; + goto out; + } namelen = dentry->d_name.len - GUID_LEN; @@ -908,8 +910,10 @@ static int efivarfs_create(struct inode *dir, struct dentry *dentry, d_instantiate(dentry, inode); dget(dentry); out: - if (err) + if (err) { kfree(var); + iput(inode); + } return err; } -- cgit v1.2.3 From 5c9b50ab8ca962bc085cfb49bae947910d73f794 Mon Sep 17 00:00:00 2001 From: Andy Whitcroft Date: Thu, 11 Oct 2012 11:32:19 +0100 Subject: efivarfs: efivarfs_fill_super() fix inode reference counts When d_make_root() fails it will automatically drop the reference on the root inode. We should not be doing so as well. Signed-off-by: Andy Whitcroft Acked-by: Matthew Garrett Acked-by: Jeremy Kerr Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 6e5f367145f..adfc4863202 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -948,7 +948,6 @@ int efivarfs_fill_super(struct super_block *sb, void *data, int silent) struct dentry *root; struct efivar_entry *entry, *n; struct efivars *efivars = &__efivars; - int err; efivarfs_sb = sb; @@ -960,18 +959,14 @@ int efivarfs_fill_super(struct super_block *sb, void *data, int silent) sb->s_time_gran = 1; inode = efivarfs_get_inode(sb, NULL, S_IFDIR | 0755, 0); - if (!inode) { - err = -ENOMEM; - goto fail; - } + if (!inode) + return -ENOMEM; inode->i_op = &efivarfs_dir_inode_operations; root = d_make_root(inode); sb->s_root = root; - if (!root) { - err = -ENOMEM; - goto fail; - } + if (!root) + return -ENOMEM; list_for_each_entry_safe(entry, n, &efivars->list, list) { struct inode *inode; @@ -1012,9 +1007,6 @@ int efivarfs_fill_super(struct super_block *sb, void *data, int silent) } return 0; -fail: - iput(inode); - return err; } static struct dentry *efivarfs_mount(struct file_system_type *fs_type, -- cgit v1.2.3 From c0359db1a1c484ea810f4d5a877d3b00d107908b Mon Sep 17 00:00:00 2001 From: Andy Whitcroft Date: Thu, 11 Oct 2012 11:32:20 +0100 Subject: efivarfs: efivarfs_fill_super() ensure we free our temporary name d_alloc_name() copies the passed name to new storage, once complete we no longer need our name. Signed-off-by: Andy Whitcroft Acked-by: Matthew Garrett Acked-by: Jeremy Kerr Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index adfc4863202..36b3dd6e1e5 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -992,6 +992,8 @@ int efivarfs_fill_super(struct super_block *sb, void *data, int silent) inode = efivarfs_get_inode(efivarfs_sb, root->d_inode, S_IFREG | 0644, 0); dentry = d_alloc_name(root, name); + /* copied by the above to local storage in the dentry. */ + kfree(name); efivars->ops->get_variable(entry->var.VariableName, &entry->var.VendorGuid, -- cgit v1.2.3 From 5ba6e2919b9e18a051e5bdd6c21f52ee4976513f Mon Sep 17 00:00:00 2001 From: Andy Whitcroft Date: Thu, 11 Oct 2012 11:32:21 +0100 Subject: efivarfs: efivarfs_fill_super() ensure we clean up correctly on error Ensure we free both the name and inode on error when building the individual variables. Signed-off-by: Andy Whitcroft Acked-by: Matthew Garrett Acked-by: Jeremy Kerr Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 36b3dd6e1e5..216086d8838 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -948,6 +948,7 @@ int efivarfs_fill_super(struct super_block *sb, void *data, int silent) struct dentry *root; struct efivar_entry *entry, *n; struct efivars *efivars = &__efivars; + char *name; efivarfs_sb = sb; @@ -969,16 +970,18 @@ int efivarfs_fill_super(struct super_block *sb, void *data, int silent) return -ENOMEM; list_for_each_entry_safe(entry, n, &efivars->list, list) { - struct inode *inode; struct dentry *dentry, *root = efivarfs_sb->s_root; - char *name; unsigned long size = 0; int len, i; + inode = NULL; + len = utf16_strlen(entry->var.VariableName); /* GUID plus trailing NULL */ name = kmalloc(len + 38, GFP_ATOMIC); + if (!name) + goto fail; for (i = 0; i < len; i++) name[i] = entry->var.VariableName[i] & 0xFF; @@ -991,7 +994,13 @@ int efivarfs_fill_super(struct super_block *sb, void *data, int silent) inode = efivarfs_get_inode(efivarfs_sb, root->d_inode, S_IFREG | 0644, 0); + if (!inode) + goto fail_name; + dentry = d_alloc_name(root, name); + if (!dentry) + goto fail_inode; + /* copied by the above to local storage in the dentry. */ kfree(name); @@ -1009,6 +1018,13 @@ int efivarfs_fill_super(struct super_block *sb, void *data, int silent) } return 0; + +fail_inode: + iput(inode); +fail_name: + kfree(name); +fail: + return -ENOMEM; } static struct dentry *efivarfs_mount(struct file_system_type *fs_type, -- cgit v1.2.3 From f5f6a60ad52fc786c517303590f1efaea614c69b Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Thu, 11 Oct 2012 21:19:11 +0800 Subject: efivarfs: Implement exclusive access for {get,set}_variable Currently, efivarfs does not enforce exclusion over the get_variable and set_variable operations. Section 7.1 of UEFI requires us to only allow a single processor to enter {get,set}_variable services at once. This change acquires the efivars->lock over calls to these operations from the efivarfs paths. Signed-off-by: Jeremy Kerr Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 68 +++++++++++++++++++++++++++++----------------- 1 file changed, 43 insertions(+), 25 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 216086d8838..d478c568ce4 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -690,35 +690,45 @@ static ssize_t efivarfs_file_write(struct file *file, goto out; } + /* + * 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). + */ + spin_lock(&efivars->lock); + status = efivars->ops->set_variable(var->var.VariableName, &var->var.VendorGuid, attributes, datasize, data); - switch (status) { - case EFI_SUCCESS: - break; - case EFI_INVALID_PARAMETER: - count = -EINVAL; - goto out; - case EFI_OUT_OF_RESOURCES: - count = -ENOSPC; - goto out; - case EFI_DEVICE_ERROR: - count = -EIO; - goto out; - case EFI_WRITE_PROTECTED: - count = -EROFS; - goto out; - case EFI_SECURITY_VIOLATION: - count = -EACCES; - goto out; - case EFI_NOT_FOUND: - count = -ENOENT; - goto out; - default: - count = -EINVAL; - goto out; + if (status != EFI_SUCCESS) { + spin_unlock(&efivars->lock); + kfree(data); + + switch (status) { + case EFI_INVALID_PARAMETER: + count = -EINVAL; + break; + case EFI_OUT_OF_RESOURCES: + count = -ENOSPC; + break; + case EFI_DEVICE_ERROR: + count = -EIO; + break; + case EFI_WRITE_PROTECTED: + count = -EROFS; + break; + case EFI_SECURITY_VIOLATION: + count = -EACCES; + break; + case EFI_NOT_FOUND: + count = -ENOENT; + break; + default: + count = -EINVAL; + } + return count; } /* @@ -734,12 +744,12 @@ static ssize_t efivarfs_file_write(struct file *file, NULL); if (status == EFI_BUFFER_TOO_SMALL) { + spin_unlock(&efivars->lock); mutex_lock(&inode->i_mutex); i_size_write(inode, newdatasize + sizeof(attributes)); mutex_unlock(&inode->i_mutex); } else if (status == EFI_NOT_FOUND) { - spin_lock(&efivars->lock); list_del(&var->list); spin_unlock(&efivars->lock); efivar_unregister(var); @@ -747,6 +757,7 @@ static ssize_t efivarfs_file_write(struct file *file, dput(file->f_dentry); } else { + spin_unlock(&efivars->lock); pr_warn("efivarfs: inconsistent EFI variable implementation? " "status = %lx\n", status); } @@ -768,9 +779,11 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, void *data; ssize_t size = 0; + spin_lock(&efivars->lock); status = efivars->ops->get_variable(var->var.VariableName, &var->var.VendorGuid, &attributes, &datasize, NULL); + spin_unlock(&efivars->lock); if (status != EFI_BUFFER_TOO_SMALL) return 0; @@ -780,10 +793,13 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, if (!data) return 0; + spin_lock(&efivars->lock); status = efivars->ops->get_variable(var->var.VariableName, &var->var.VendorGuid, &attributes, &datasize, (data + 4)); + spin_unlock(&efivars->lock); + if (status != EFI_SUCCESS) goto out_free; @@ -1004,11 +1020,13 @@ int efivarfs_fill_super(struct super_block *sb, void *data, int silent) /* copied by the above to local storage in the dentry. */ kfree(name); + spin_lock(&efivars->lock); efivars->ops->get_variable(entry->var.VariableName, &entry->var.VendorGuid, &entry->var.Attributes, &size, NULL); + spin_unlock(&efivars->lock); mutex_lock(&inode->i_mutex); inode->i_private = entry; -- cgit v1.2.3 From 310ad75448329f167af3c4a10e4a9de4d80058ff Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Fri, 19 Oct 2012 15:16:45 +0800 Subject: efi: Clarify GUID length calculations At present, the handling of GUIDs in efivar file names isn't consistent. We use GUID_LEN in some places, and 38 in others (GUID_LEN plus separator), and implicitly use the presence of the trailing NUL. This change removes the trailing NUL from GUID_LEN, so that we're explicitly adding it when required. We also replace magic numbers with GUID_LEN, and clarify the comments where appropriate. We also fix the allocation size in efivar_create_sysfs_entry, where we're allocating one byte too much, due to counting the trailing NUL twice - once when calculating short_name_size, and once in the kzalloc. Signed-off-by: Jeremy Kerr Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 33 +++++++++++++++++++++++++-------- 1 file changed, 25 insertions(+), 8 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index d478c568ce4..a93e401c20a 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -95,7 +95,12 @@ MODULE_LICENSE("GPL"); MODULE_VERSION(EFIVARS_VERSION); #define DUMP_NAME_LEN 52 -#define GUID_LEN 37 + +/* + * Length of a GUID string (strlen("aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee")) + * not including trailing NUL + */ +#define GUID_LEN 36 /* * The maximum size of VariableName + Data = 1024 @@ -887,7 +892,11 @@ static int efivarfs_create(struct inode *dir, struct dentry *dentry, struct efivar_entry *var; int namelen, i = 0, err = 0; - if (dentry->d_name.len < 38) + /* + * We need a GUID, plus at least one letter for the variable name, + * plus the '-' separator + */ + if (dentry->d_name.len < GUID_LEN + 2) return -EINVAL; inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0); @@ -900,7 +909,8 @@ static int efivarfs_create(struct inode *dir, struct dentry *dentry, goto out; } - namelen = dentry->d_name.len - GUID_LEN; + /* length of the variable name itself: remove GUID and separator */ + namelen = dentry->d_name.len - GUID_LEN - 1; efivarfs_hex_to_guid(dentry->d_name.name + namelen + 1, &var->var.VendorGuid); @@ -994,8 +1004,8 @@ int efivarfs_fill_super(struct super_block *sb, void *data, int silent) len = utf16_strlen(entry->var.VariableName); - /* GUID plus trailing NULL */ - name = kmalloc(len + 38, GFP_ATOMIC); + /* name, plus '-', plus GUID, plus NUL*/ + name = kmalloc(len + 1 + GUID_LEN + 1, GFP_ATOMIC); if (!name) goto fail; @@ -1006,7 +1016,7 @@ int efivarfs_fill_super(struct super_block *sb, void *data, int silent) efi_guid_unparse(&entry->var.VendorGuid, name + len + 1); - name[len+GUID_LEN] = '\0'; + name[len+GUID_LEN+1] = '\0'; inode = efivarfs_get_inode(efivarfs_sb, root->d_inode, S_IFREG | 0644, 0); @@ -1435,11 +1445,18 @@ efivar_create_sysfs_entry(struct efivars *efivars, efi_char16_t *variable_name, efi_guid_t *vendor_guid) { - int i, short_name_size = variable_name_size / sizeof(efi_char16_t) + 38; + int i, short_name_size; char *short_name; struct efivar_entry *new_efivar; - short_name = kzalloc(short_name_size + 1, GFP_KERNEL); + /* + * Length of the variable bytes in ASCII, plus the '-' separator, + * plus the GUID, plus trailing NUL + */ + short_name_size = variable_name_size / sizeof(efi_char16_t) + + 1 + GUID_LEN + 1; + + short_name = kzalloc(short_name_size, GFP_KERNEL); new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL); if (!short_name || !new_efivar) { -- cgit v1.2.3 From 7253eaba7b179db2e07e67c5b78d5f10b332291d Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Tue, 16 Oct 2012 15:58:07 +0100 Subject: efivarfs: Return an error if we fail to read a variable Instead of always returning 0 in efivarfs_file_read(), even when we fail to successfully read the variable, convert the EFI status to something meaningful and return that to the caller. This way the user will have some hint as to why the read failed. Acked-by: Jeremy Kerr Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 62 +++++++++++++++++++++++++++------------------- 1 file changed, 36 insertions(+), 26 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index a93e401c20a..277e42616f0 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -653,6 +653,36 @@ static int efivarfs_file_open(struct inode *inode, struct file *file) return 0; } +static int efi_status_to_err(efi_status_t status) +{ + int err; + + switch (status) { + case EFI_INVALID_PARAMETER: + err = -EINVAL; + break; + case EFI_OUT_OF_RESOURCES: + err = -ENOSPC; + break; + case EFI_DEVICE_ERROR: + err = -EIO; + break; + case EFI_WRITE_PROTECTED: + err = -EROFS; + break; + case EFI_SECURITY_VIOLATION: + err = -EACCES; + break; + case EFI_NOT_FOUND: + err = -ENOENT; + break; + default: + err = -EINVAL; + } + + return err; +} + static ssize_t efivarfs_file_write(struct file *file, const char __user *userbuf, size_t count, loff_t *ppos) { @@ -711,29 +741,7 @@ static ssize_t efivarfs_file_write(struct file *file, spin_unlock(&efivars->lock); kfree(data); - switch (status) { - case EFI_INVALID_PARAMETER: - count = -EINVAL; - break; - case EFI_OUT_OF_RESOURCES: - count = -ENOSPC; - break; - case EFI_DEVICE_ERROR: - count = -EIO; - break; - case EFI_WRITE_PROTECTED: - count = -EROFS; - break; - case EFI_SECURITY_VIOLATION: - count = -EACCES; - break; - case EFI_NOT_FOUND: - count = -ENOENT; - break; - default: - count = -EINVAL; - } - return count; + return efi_status_to_err(status); } /* @@ -791,12 +799,12 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, spin_unlock(&efivars->lock); if (status != EFI_BUFFER_TOO_SMALL) - return 0; + return efi_status_to_err(status); data = kmalloc(datasize + 4, GFP_KERNEL); if (!data) - return 0; + return -ENOMEM; spin_lock(&efivars->lock); status = efivars->ops->get_variable(var->var.VariableName, @@ -805,8 +813,10 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, (data + 4)); spin_unlock(&efivars->lock); - if (status != EFI_SUCCESS) + if (status != EFI_SUCCESS) { + size = efi_status_to_err(status); goto out_free; + } memcpy(data, &attributes, 4); size = simple_read_from_buffer(userbuf, count, ppos, -- cgit v1.2.3 From d292384152fdd465dba792d555ce5db83e94efa0 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Mon, 22 Oct 2012 15:23:29 +0100 Subject: efivarfs: Replace magic number with sizeof(attributes) Seeing "+ 4" littered throughout the functions gets a bit confusing. Use "sizeof(attributes)" which clearly explains what quantity we're adding. Acked-by: Jeremy Kerr Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 277e42616f0..2c044343c99 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -801,7 +801,7 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, if (status != EFI_BUFFER_TOO_SMALL) return efi_status_to_err(status); - data = kmalloc(datasize + 4, GFP_KERNEL); + data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL); if (!data) return -ENOMEM; @@ -810,7 +810,7 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, status = efivars->ops->get_variable(var->var.VariableName, &var->var.VendorGuid, &attributes, &datasize, - (data + 4)); + (data + sizeof(attributes))); spin_unlock(&efivars->lock); if (status != EFI_SUCCESS) { @@ -818,9 +818,9 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, goto out_free; } - memcpy(data, &attributes, 4); + memcpy(data, &attributes, sizeof(attributes)); size = simple_read_from_buffer(userbuf, count, ppos, - data, datasize + 4); + data, datasize + sizeof(attributes)); out_free: kfree(data); -- cgit v1.2.3 From 91716322d834cba34f4a7ed5e4a39673eb90862b Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Mon, 22 Oct 2012 15:51:45 +0100 Subject: efivarfs: Add unique magic number Using pstore's superblock magic number is no doubt going to cause problems in the future. Give efivarfs its own magic number. Acked-by: Jeremy Kerr Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 2c044343c99..3b0cf9acb50 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -991,7 +991,7 @@ int efivarfs_fill_super(struct super_block *sb, void *data, int silent) sb->s_maxbytes = MAX_LFS_FILESIZE; sb->s_blocksize = PAGE_CACHE_SIZE; sb->s_blocksize_bits = PAGE_CACHE_SHIFT; - sb->s_magic = PSTOREFS_MAGIC; + sb->s_magic = EFIVARFS_MAGIC; sb->s_op = &efivarfs_ops; sb->s_time_gran = 1; -- cgit v1.2.3 From 07b1c5bc64cff9c880261a1fef562ef7ea7f6575 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Tue, 23 Oct 2012 12:35:43 +0100 Subject: efivarfs: Make 'datasize' unsigned long There's no reason to declare 'datasize' as an int, since the majority of the functions it's passed to expect an unsigned long anyway. Plus, this way we avoid any sign problems during arithmetic. Acked-by: Jeremy Kerr Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 3b0cf9acb50..6a858d1a5bb 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -692,7 +692,7 @@ static ssize_t efivarfs_file_write(struct file *file, void *data; u32 attributes; struct inode *inode = file->f_mapping->host; - int datasize = count - sizeof(attributes); + unsigned long datasize = count - sizeof(attributes); unsigned long newdatasize; if (count < sizeof(attributes)) -- cgit v1.2.3 From aeeaa8d46aa38c9cc5fac23feb9b1f91bdbf5dd3 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Tue, 23 Oct 2012 12:41:03 +0100 Subject: efivarfs: Return a consistent error when efivarfs_get_inode() fails Instead of returning -ENOSPC if efivarfs_get_inode() fails we should be returning -ENOMEM, since running out of memory is the only reason it can fail. Furthermore, that's the error value used everywhere else in this file. It's also less likely to confuse users that hit this error case. Acked-by: Jeremy Kerr Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 6a858d1a5bb..58cec627a82 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -911,7 +911,7 @@ static int efivarfs_create(struct inode *dir, struct dentry *dentry, inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0); if (!inode) - return -ENOSPC; + return -ENOMEM; var = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL); if (!var) { -- cgit v1.2.3 From cfcf2f11708f934d2bd294f973c2fcb0cc54f293 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Fri, 26 Oct 2012 12:18:53 +0100 Subject: efivarfs: Fix return value of efivarfs_file_write() We're stuffing a variable of type size_t (unsigned) into a ssize_t (signed) which, even though both types should be the same number of bits, it's just asking for sign issues to be introduced. Cc: Jeremy Kerr Reported-by: Alan Cox Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 58cec627a82..9ac934018bb 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -694,6 +694,7 @@ static ssize_t efivarfs_file_write(struct file *file, struct inode *inode = file->f_mapping->host; unsigned long datasize = count - sizeof(attributes); unsigned long newdatasize; + ssize_t bytes = 0; if (count < sizeof(attributes)) return -EINVAL; @@ -706,22 +707,22 @@ static ssize_t efivarfs_file_write(struct file *file, efivars = var->efivars; if (copy_from_user(&attributes, userbuf, sizeof(attributes))) { - count = -EFAULT; + bytes = -EFAULT; goto out; } if (attributes & ~(EFI_VARIABLE_MASK)) { - count = -EINVAL; + bytes = -EINVAL; goto out; } if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) { - count = -EFAULT; + bytes = -EFAULT; goto out; } if (validate_var(&var->var, data, datasize) == false) { - count = -EINVAL; + bytes = -EINVAL; goto out; } @@ -744,6 +745,8 @@ static ssize_t efivarfs_file_write(struct file *file, return efi_status_to_err(status); } + bytes = count; + /* * 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 @@ -778,7 +781,7 @@ static ssize_t efivarfs_file_write(struct file *file, out: kfree(data); - return count; + return bytes; } static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, -- cgit v1.2.3 From 89d16665d388837b30972081d97b814be26d68a2 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Fri, 9 Nov 2012 21:02:56 +0000 Subject: efivarfs: Use query_variable_info() to limit kmalloc() We don't want someone who can write EFI variables to be able to allocate arbitrarily large amounts of memory, so cap it to something sensible like the amount of free space for EFI variables. Acked-by: Jeremy Kerr Cc: Matthew Garrett Cc: Alan Cox Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 43 ++++++++++++++++++++++++++++++++++--------- 1 file changed, 34 insertions(+), 9 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 9ac934018bb..d6b8d2f628f 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -694,28 +694,51 @@ static ssize_t efivarfs_file_write(struct file *file, struct inode *inode = file->f_mapping->host; unsigned long datasize = count - sizeof(attributes); unsigned long newdatasize; + u64 storage_size, remaining_size, max_size; ssize_t bytes = 0; if (count < sizeof(attributes)) return -EINVAL; - data = kmalloc(datasize, GFP_KERNEL); + if (copy_from_user(&attributes, userbuf, sizeof(attributes))) + return -EFAULT; - if (!data) - return -ENOMEM; + if (attributes & ~(EFI_VARIABLE_MASK)) + return -EINVAL; efivars = var->efivars; - if (copy_from_user(&attributes, userbuf, sizeof(attributes))) { - bytes = -EFAULT; - goto out; + /* + * Ensure that the user can't allocate arbitrarily large + * amounts of memory. Pick a default size of 64K if + * QueryVariableInfo() isn't supported by the firmware. + */ + spin_lock(&efivars->lock); + + if (!efivars->ops->query_variable_info) + status = EFI_UNSUPPORTED; + else { + const struct efivar_operations *fops = efivars->ops; + status = fops->query_variable_info(attributes, &storage_size, + &remaining_size, &max_size); } - if (attributes & ~(EFI_VARIABLE_MASK)) { - bytes = -EINVAL; - goto out; + spin_unlock(&efivars->lock); + + if (status != EFI_SUCCESS) { + if (status != EFI_UNSUPPORTED) + return efi_status_to_err(status); + + remaining_size = 65536; } + if (datasize > remaining_size) + return -ENOSPC; + + data = kmalloc(datasize, GFP_KERNEL); + if (!data) + return -ENOMEM; + if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) { bytes = -EFAULT; goto out; @@ -1709,6 +1732,8 @@ efivars_init(void) ops.get_variable = efi.get_variable; ops.set_variable = efi.set_variable; ops.get_next_variable = efi.get_next_variable; + ops.query_variable_info = efi.query_variable_info; + error = register_efivars(&__efivars, &ops, efi_kobj); if (error) goto err_put; -- cgit v1.2.3 From e83af1f18c78c7b6aa720beecc927ecc8afd3647 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Thu, 15 Nov 2012 20:03:16 +0000 Subject: efivarfs: Make efivarfs_fill_super() static sparse is complaining that efivarfs_fill_super() doesn't have a prototype. Make it static to avoid the warning. Cc: Xie ChanglongX Cc: Matthew Garrett Cc: Jeremy Kerr Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index d6b8d2f628f..47aae91ff72 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -1004,7 +1004,7 @@ static int efivarfs_unlink(struct inode *dir, struct dentry *dentry) return -EINVAL; }; -int efivarfs_fill_super(struct super_block *sb, void *data, int silent) +static int efivarfs_fill_super(struct super_block *sb, void *data, int silent) { struct inode *inode = NULL; struct dentry *root; -- cgit v1.2.3