efivarfs: Fix error on non-existent file

When looking up a non-existent file, efivarfs returns -EINVAL if the
file does not conform to the NAME-GUID format and -ENOENT if it does.
This is caused by efivars_d_hash() returning -EINVAL if the name is not
formatted correctly.  This error is returned before simple_lookup()
returns a negative dentry, and is the error value that the user sees.

Fix by removing this check.  If the file does not exist, simple_lookup()
will return a negative dentry leading to -ENOENT and efivarfs_create()
already has a validity check before it creates an entry (and will
correctly return -EINVAL)

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: <stable@vger.kernel.org>
[ardb: make efivarfs_valid_name() static]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
This commit is contained in:
James Bottomley 2024-12-08 13:34:13 -05:00 committed by Ard Biesheuvel
parent 0b2c29fb68
commit 2ab0837cb9
3 changed files with 1 additions and 5 deletions

View File

@ -51,7 +51,7 @@ struct inode *efivarfs_get_inode(struct super_block *sb,
*
* VariableName-12345678-1234-1234-1234-1234567891bc
*/
bool efivarfs_valid_name(const char *str, int len)
static bool efivarfs_valid_name(const char *str, int len)
{
const char *s = str + len - EFI_VARIABLE_GUID_LEN;

View File

@ -60,7 +60,6 @@ bool efivar_variable_is_removable(efi_guid_t vendor, const char *name,
extern const struct file_operations efivarfs_file_operations;
extern const struct inode_operations efivarfs_dir_inode_operations;
extern bool efivarfs_valid_name(const char *str, int len);
extern struct inode *efivarfs_get_inode(struct super_block *sb,
const struct inode *dir, int mode, dev_t dev,
bool is_removable);

View File

@ -144,9 +144,6 @@ static int efivarfs_d_hash(const struct dentry *dentry, struct qstr *qstr)
const unsigned char *s = qstr->name;
unsigned int len = qstr->len;
if (!efivarfs_valid_name(s, len))
return -EINVAL;
while (len-- > EFI_VARIABLE_GUID_LEN)
hash = partial_name_hash(*s++, hash);