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Commit 900281e1 authored by Len Brown's avatar Len Brown Committed by Greg Kroah-Hartman
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powercap: restrict energy meter to root access 



commit 949dd0104c496fa7c14991a23c03c62e44637e71 upstream.

Remove non-privileged user access to power data contained in
/sys/class/powercap/intel-rapl*/*/energy_uj

Non-privileged users currently have read access to power data and can
use this data to form a security attack. Some privileged
drivers/applications need read access to this data, but don't expose it
to non-privileged users.

For example, thermald uses this data to ensure that power management
works correctly. Thus removing non-privileged access is preferred over
completely disabling this power reporting capability with
CONFIG_INTEL_RAPL=n.

Fixes: 95677a9a ("PowerCap: Fix mode for energy counter")
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 53fff24a

drivers/powercap/powercap_sys.c

+2 −2
Original line number Diff line number Diff line
@@ -379,9 +379,9 @@ static void create_power_zone_common_attributes( 
					&dev_attr_max_energy_range_uj.attr;

	if (power_zone->ops->get_energy_uj) {

		if (power_zone->ops->reset_energy_uj)

			dev_attr_energy_uj.attr.mode = S_IWUSR | S_IRUGO;

			dev_attr_energy_uj.attr.mode = S_IWUSR | S_IRUSR;

		else

			dev_attr_energy_uj.attr.mode = S_IRUGO;

			dev_attr_energy_uj.attr.mode = S_IRUSR;

		power_zone->zone_dev_attrs[count++] =

					&dev_attr_energy_uj.attr;

	}