efivarfs: Replace invalid slashes with exclamation marks in dentries.

commit 336af6a4686d885a067ecea8c3c3dd129ba4fc75 upstream.

Without this patch efivarfs_alloc_dentry creates dentries with slashes in
their name if the respective EFI variable has slashes in its name. This in
turn causes EIO on getdents64, which prevents a complete directory listing
of /sys/firmware/efi/efivars/.

This patch replaces the invalid shlashes with exclamation marks like
kobject_set_name_vargs does for /sys/firmware/efi/vars/ to have consistently
named dentries under /sys/firmware/efi/vars/ and /sys/firmware/efi/efivars/.

Signed-off-by: Michael Schaller <misch@google.com>
Link: https://lore.kernel.org/r/20200925074502.150448-1-misch@google.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: dann frazier <dann.frazier@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c
index 28bb5689333a59a69fa46bc6beba8e8d1f81acd2..15880a68faadc58ba34d1a3f68ac412416202f2e 100644 (file)
--- a/fs/efivarfs/super.c
+++ b/fs/efivarfs/super.c
@@ -141,6 +141,9 @@ static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor,
 
        name[len + EFI_VARIABLE_GUID_LEN+1] = '\0';
 
+       /* replace invalid slashes like kobject_set_name_vargs does for /sys/firmware/efi/vars. */
+       strreplace(name, '/', '!');
+
        inode = efivarfs_get_inode(sb, d_inode(root), S_IFREG | 0644, 0,
                                   is_removable);
        if (!inode)