futex: only attach to the owner within process group for private futex
It is possible to lock on a lock with an uaddr value of a random process.
No harm is done, the waiter will be blocked until the process with the
chosen pid exits - which wakes the waiter.
There should be no way to abuse this and turn it into something
malicious. However it makes no sense to allow a private futex to queue
its PI state on a process which it has nothing to do with. So reject such
attempt.
This is just another corner case in the futex code, nothing special.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bigeasy@l.de: description]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
1 file changed
