[PATCH] efi/esrt: Allow ESRT access without CAP_SYS_ADMIN

From: Nicholas Bishop
Date: Fri May 12 2023 - 15:43:18 EST


Access to the files in /sys/firmware/efi/esrt has been restricted to
CAP_SYS_ADMIN since support for ESRT was added, but this seems overly
restrictive given that the files are read-only and just provide
information about UEFI firmware updates.

Remove the CAP_SYS_ADMIN restriction so that a non-root process can read
the files, provided a suitably-privileged process changes the file
ownership first. The files are still read-only and still owned by root by
default.

Signed-off-by: Nicholas Bishop <nicholasbishop@xxxxxxxxxx>
---
drivers/firmware/efi/esrt.c | 4 ----
1 file changed, 4 deletions(-)

diff --git a/drivers/firmware/efi/esrt.c b/drivers/firmware/efi/esrt.c
index d5915272141f..aab96ab64a1a 100644
--- a/drivers/firmware/efi/esrt.c
+++ b/drivers/firmware/efi/esrt.c
@@ -95,10 +95,6 @@ static ssize_t esre_attr_show(struct kobject *kobj,
struct esre_entry *entry = to_entry(kobj);
struct esre_attribute *attr = to_attr(_attr);

- /* Don't tell normal users what firmware versions we've got... */
- if (!capable(CAP_SYS_ADMIN))
- return -EACCES;
-
return attr->show(entry, buf);
}

--
2.40.1.606.ga4b1b128d6-goog