sched: Disallow sched_attr::sched_policy < 0
authorPeter Zijlstra <peterz@infradead.org>
Fri, 9 May 2014 08:49:03 +0000 (10:49 +0200)
committerIngo Molnar <mingo@kernel.org>
Thu, 22 May 2014 08:21:26 +0000 (10:21 +0200)
The scheduler uses policy=-1 to preserve the current policy state to
implement sys_sched_setparam(), this got exposed to userspace by
accident through sys_sched_setattr(), cure this.

Reported-by: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: <stable@vger.kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140509085311.GJ30445@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kernel/sched/core.c

index f2205f02eb7008224037382c73463cc49f110bdc..cdefcf7c5925346782c6af4da3dcbeb2708fb261 100644 (file)
@@ -3662,6 +3662,9 @@ SYSCALL_DEFINE3(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr,
        if (retval)
                return retval;
 
+       if (attr.sched_policy < 0)
+               return -EINVAL;
+
        rcu_read_lock();
        retval = -ESRCH;
        p = find_process_by_pid(pid);