timerfd: Reject ALARM timerfds without CAP_WAKE_ALARM
authorEric Caruso <ejcaruso@google.com>
Wed, 8 Jun 2016 23:08:59 +0000 (16:08 -0700)
committerThomas Gleixner <tglx@linutronix.de>
Thu, 9 Jun 2016 21:42:38 +0000 (23:42 +0200)
commit2895a5e5b3ae78d9923a91fce405d4a2f32c4309
tree8168121926c218cc7896c0eacc4382ecdaca3d0c
parentaf8c34ce6ae32addda3788d54a7e340cad22516b
timerfd: Reject ALARM timerfds without CAP_WAKE_ALARM

timerfd gives processes a way to set wake alarms, but unlike timers made using
timer_create, timerfds don't check whether the process has CAP_WAKE_ALARM
before setting alarm-time timers. CAP_WAKE_ALARM is supposed to gate this
behavior and so it makes sense that we should deny permission to create such
timerfds if the process doesn't have this capability.

Signed-off-by: Eric Caruso <ejcaruso@google.com>
Cc: Todd Poynor <toddpoynor@google.com>
Link: http://lkml.kernel.org/r/1465427339-96209-1-git-send-email-ejcaruso@chromium.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
fs/timerfd.c