5.4-stable review patch. If anyone has any objections, please let me know.
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From: James Bottomley James.Bottomley@HansenPartnership.com
commit 2ab0837cb91b7de507daa145d17b3b6b2efb3abf upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/efivarfs/inode.c | 2 +- fs/efivarfs/internal.h | 1 - fs/efivarfs/super.c | 3 --- 3 files changed, 1 insertion(+), 5 deletions(-)
--- a/fs/efivarfs/inode.c +++ b/fs/efivarfs/inode.c @@ -43,7 +43,7 @@ struct inode *efivarfs_get_inode(struct * * 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;
--- a/fs/efivarfs/internal.h +++ b/fs/efivarfs/internal.h @@ -10,7 +10,6 @@
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); --- a/fs/efivarfs/super.c +++ b/fs/efivarfs/super.c @@ -63,9 +63,6 @@ static int efivarfs_d_hash(const struct 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);