[PATCH] efivarfs: Replace invalid slashes with exclamation marks in dentries.

From: Michael Schaller
Date: Fri Sep 18 2020 - 07:27:43 EST


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

diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c
index 28bb5689333a..15880a68faad 100644
--- 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)
--
2.28.0.681.g6f77f65b4e-goog