Commit 06a9ec29 authored Jul 10, 2006 by Thomas Gleixner Committed by Linus Torvalds Jul 10, 2006

[PATCH] pi-futex: Validate futex type instead of oopsing

Calling futex_lock_pi is called with a reference to a non PI futex and
waiters exist already, lookup_pi_state() oopses due to pi_state == NULL.
Check this condition and return -EINVAL to userspace.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent bed936f7

kernel/futex.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -476,6 +476,12 @@ lookup_pi_state(u32 uval, struct futex_hash_bucket hb, struct futex_q me)
		* the refcount and return its pi_state:
		*/
		pi_state = this->pi_state;
		/*
		* Userspace might have messed up non PI and PI futexes
		*/
		if (unlikely(!pi_state))
		return -EINVAL;

		atomic_inc(&pi_state->refcount);
		me->pi_state = pi_state;