diff options
| -rw-r--r-- | drivers/firmware/efivars.c | 130 | ||||
| -rw-r--r-- | tools/testing/selftests/efivarfs/efivarfs.sh | 59 |
2 files changed, 155 insertions, 34 deletions
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 7320bf891706..bea32d1ef7d5 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -426,6 +426,44 @@ get_var_data(struct efivars *efivars, struct efi_variable *var) return status; } +static efi_status_t +check_var_size_locked(struct efivars *efivars, u32 attributes, + unsigned long size) +{ + u64 storage_size, remaining_size, max_size; + efi_status_t status; + const struct efivar_operations *fops = efivars->ops; + + if (!efivars->ops->query_variable_info) + return EFI_UNSUPPORTED; + + status = fops->query_variable_info(attributes, &storage_size, + &remaining_size, &max_size); + + if (status != EFI_SUCCESS) + return status; + + if (!storage_size || size > remaining_size || size > max_size || + (remaining_size - size) < (storage_size / 2)) + return EFI_OUT_OF_RESOURCES; + + return status; +} + + +static efi_status_t +check_var_size(struct efivars *efivars, u32 attributes, unsigned long size) +{ + efi_status_t status; + unsigned long flags; + + spin_lock_irqsave(&efivars->lock, flags); + status = check_var_size_locked(efivars, attributes, size); + spin_unlock_irqrestore(&efivars->lock, flags); + + return status; +} + static ssize_t efivar_guid_read(struct efivar_entry *entry, char *buf) { @@ -547,11 +585,16 @@ efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count) } spin_lock_irq(&efivars->lock); - status = efivars->ops->set_variable(new_var->VariableName, - &new_var->VendorGuid, - new_var->Attributes, - new_var->DataSize, - new_var->Data); + + status = check_var_size_locked(efivars, new_var->Attributes, + new_var->DataSize + utf16_strsize(new_var->VariableName, 1024)); + + if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED) + status = efivars->ops->set_variable(new_var->VariableName, + &new_var->VendorGuid, + new_var->Attributes, + new_var->DataSize, + new_var->Data); spin_unlock_irq(&efivars->lock); @@ -702,8 +745,7 @@ static ssize_t efivarfs_file_write(struct file *file, u32 attributes; struct inode *inode = file->f_mapping->host; unsigned long datasize = count - sizeof(attributes); - unsigned long newdatasize; - u64 storage_size, remaining_size, max_size; + unsigned long newdatasize, varsize; ssize_t bytes = 0; if (count < sizeof(attributes)) @@ -722,28 +764,18 @@ static ssize_t efivarfs_file_write(struct file *file, * amounts of memory. Pick a default size of 64K if * QueryVariableInfo() isn't supported by the firmware. */ - spin_lock_irq(&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); - } - spin_unlock_irq(&efivars->lock); + varsize = datasize + utf16_strsize(var->var.VariableName, 1024); + status = check_var_size(efivars, attributes, varsize); if (status != EFI_SUCCESS) { if (status != EFI_UNSUPPORTED) return efi_status_to_err(status); - remaining_size = 65536; + if (datasize > 65536) + return -ENOSPC; } - if (datasize > remaining_size) - return -ENOSPC; - data = kmalloc(datasize, GFP_KERNEL); if (!data) return -ENOMEM; @@ -765,6 +797,19 @@ static ssize_t efivarfs_file_write(struct file *file, */ spin_lock_irq(&efivars->lock); + /* + * Ensure that the available space hasn't shrunk below the safe level + */ + + status = check_var_size_locked(efivars, attributes, varsize); + + if (status != EFI_SUCCESS && status != EFI_UNSUPPORTED) { + spin_unlock_irq(&efivars->lock); + kfree(data); + + return efi_status_to_err(status); + } + status = efivars->ops->set_variable(var->var.VariableName, &var->var.VendorGuid, attributes, datasize, @@ -929,8 +974,8 @@ static bool efivarfs_valid_name(const char *str, int len) if (len < GUID_LEN + 2) return false; - /* GUID should be right after the first '-' */ - if (s - 1 != strchr(str, '-')) + /* GUID must be preceded by a '-' */ + if (*(s - 1) != '-') return false; /* @@ -1118,15 +1163,22 @@ static struct dentry_operations efivarfs_d_ops = { static struct dentry *efivarfs_alloc_dentry(struct dentry *parent, char *name) { + struct dentry *d; struct qstr q; + int err; q.name = name; q.len = strlen(name); - if (efivarfs_d_hash(NULL, NULL, &q)) - return NULL; + err = efivarfs_d_hash(NULL, NULL, &q); + if (err) + return ERR_PTR(err); + + d = d_alloc(parent, &q); + if (d) + return d; - return d_alloc(parent, &q); + return ERR_PTR(-ENOMEM); } static int efivarfs_fill_super(struct super_block *sb, void *data, int silent) @@ -1136,6 +1188,7 @@ static int efivarfs_fill_super(struct super_block *sb, void *data, int silent) struct efivar_entry *entry, *n; struct efivars *efivars = &__efivars; char *name; + int err = -ENOMEM; efivarfs_sb = sb; @@ -1186,8 +1239,10 @@ static int efivarfs_fill_super(struct super_block *sb, void *data, int silent) goto fail_name; dentry = efivarfs_alloc_dentry(root, name); - if (!dentry) + if (IS_ERR(dentry)) { + err = PTR_ERR(dentry); goto fail_inode; + } /* copied by the above to local storage in the dentry. */ kfree(name); @@ -1214,7 +1269,7 @@ fail_inode: fail_name: kfree(name); fail: - return -ENOMEM; + return err; } static struct dentry *efivarfs_mount(struct file_system_type *fs_type, @@ -1345,7 +1400,6 @@ static int efi_pstore_write(enum pstore_type_id type, efi_guid_t vendor = LINUX_EFI_CRASH_GUID; struct efivars *efivars = psi->data; int i, ret = 0; - u64 storage_space, remaining_space, max_variable_size; efi_status_t status = EFI_NOT_FOUND; unsigned long flags; @@ -1365,11 +1419,11 @@ static int efi_pstore_write(enum pstore_type_id type, * size: a size of logging data * DUMP_NAME_LEN * 2: a maximum size of variable name */ - status = efivars->ops->query_variable_info(PSTORE_EFI_ATTRIBUTES, - &storage_space, - &remaining_space, - &max_variable_size); - if (status || remaining_space < size + DUMP_NAME_LEN * 2) { + + status = check_var_size_locked(efivars, PSTORE_EFI_ATTRIBUTES, + size + DUMP_NAME_LEN * 2); + + if (status) { spin_unlock_irqrestore(&efivars->lock, flags); *id = part; return -ENOSPC; @@ -1544,6 +1598,14 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj, return -EINVAL; } + status = check_var_size_locked(efivars, new_var->Attributes, + new_var->DataSize + utf16_strsize(new_var->VariableName, 1024)); + + if (status && status != EFI_UNSUPPORTED) { + spin_unlock_irq(&efivars->lock); + return efi_status_to_err(status); + } + /* now *really* create the variable via EFI */ status = efivars->ops->set_variable(new_var->VariableName, &new_var->VendorGuid, diff --git a/tools/testing/selftests/efivarfs/efivarfs.sh b/tools/testing/selftests/efivarfs/efivarfs.sh index 880cdd5dc63f..77edcdcc016b 100644 --- a/tools/testing/selftests/efivarfs/efivarfs.sh +++ b/tools/testing/selftests/efivarfs/efivarfs.sh @@ -125,6 +125,63 @@ test_open_unlink() ./open-unlink $file } +# test that we can create a range of filenames +test_valid_filenames() +{ + local attrs='\x07\x00\x00\x00' + local ret=0 + + local file_list="abc dump-type0-11-1-1362436005 1234 -" + for f in $file_list; do + local file=$efivarfs_mount/$f-$test_guid + + printf "$attrs\x00" > $file + + if [ ! -e $file ]; then + echo "$file could not be created" >&2 + ret=1 + else + rm $file + fi + done + + exit $ret +} + +test_invalid_filenames() +{ + local attrs='\x07\x00\x00\x00' + local ret=0 + + local file_list=" + -1234-1234-1234-123456789abc + foo + foo-bar + -foo- + foo-barbazba-foob-foob-foob-foobarbazfoo + foo------------------------------------- + -12345678-1234-1234-1234-123456789abc + a-12345678=1234-1234-1234-123456789abc + a-12345678-1234=1234-1234-123456789abc + a-12345678-1234-1234=1234-123456789abc + a-12345678-1234-1234-1234=123456789abc + 1112345678-1234-1234-1234-123456789abc" + + for f in $file_list; do + local file=$efivarfs_mount/$f + + printf "$attrs\x00" 2>/dev/null > $file + + if [ -e $file ]; then + echo "Creating $file should have failed" >&2 + rm $file + ret=1 + fi + done + + exit $ret +} + check_prereqs rc=0 @@ -135,5 +192,7 @@ run_test test_create_read run_test test_delete run_test test_zero_size_delete run_test test_open_unlink +run_test test_valid_filenames +run_test test_invalid_filenames exit $rc |