PM / Sleep: Require CAP_BLOCK_SUSPEND to use wake_lock/wake_unlock
Require processes wanting to use the wake_lock/wake_unlock sysfs
files to have the CAP_BLOCK_SUSPEND capability, which also is
required for the eventpoll EPOLLWAKEUP flag to be effective, so that
all interfaces related to blocking autosleep depend on the same
capability.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: stable@vger.kernel.org
Acked-by: Michael Kerrisk <mtk.man-pages@gmail.com>
diff --git a/kernel/power/wakelock.c b/kernel/power/wakelock.c
index c8fba33..8f50de3 100644
--- a/kernel/power/wakelock.c
+++ b/kernel/power/wakelock.c
@@ -9,6 +9,7 @@
* manipulate wakelocks on Android.
*/
+#include <linux/capability.h>
#include <linux/ctype.h>
#include <linux/device.h>
#include <linux/err.h>
@@ -188,6 +189,9 @@
size_t len;
int ret = 0;
+ if (!capable(CAP_BLOCK_SUSPEND))
+ return -EPERM;
+
while (*str && !isspace(*str))
str++;
@@ -231,6 +235,9 @@
size_t len;
int ret = 0;
+ if (!capable(CAP_BLOCK_SUSPEND))
+ return -EPERM;
+
len = strlen(buf);
if (!len)
return -EINVAL;