[PATCH 5.4 09/49] efivarfs: Replace invalid slashes with exclamation marks in dentries.

Greg Kroah-Hartman
2020-10-31T11:36:17Z

From: Michael Schaller <misch@google.com>

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>

---
fs/efivarfs/super.c | 3 +++
1 file changed, 3 insertions(+)

--- a/fs/efivarfs/super.c
+++ b/fs/efivarfs/super.c
@@ -141,6 +141,9 @@ static int efivarfs_callback(efi_char16_

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)