From: Jeremy Kerr <[email protected]> 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 <[email protected]> Signed-off-by: Matt Fleming <[email protected]> --- drivers/firmware/efivars.c | 33 +++++++++++++++++++++++++-------- 1 file changed, 25 insertions(+), 8 deletions(-) diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 03e0df2..c532854 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) { -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
