Commit 42eb088e authored Nov 19, 2013 by Peter Zijlstra Committed by Ingo Molnar Nov 19, 2013

sched: Avoid NULL dereference on sd_busy



Commit 37dc6b50 ("sched: Remove unnecessary iteration over sched
domains to update nr_busy_cpus") forgot to clear 'sd_busy' under some
conditions leading to a possible NULL deref in set_cpu_sd_state_idle().

Reported-by: Anton Blanchard <anton@samba.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131118113701.GF3866@twins.programming.kicks-ass.net


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 9abf24d4

kernel/sched/core.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -4910,8 +4910,9 @@ static void update_top_cache_domain(int cpu)
		if (sd) {
		id = cpumask_first(sched_domain_span(sd));
		size = cpumask_weight(sched_domain_span(sd));
		rcu_assign_pointer(per_cpu(sd_busy, cpu), sd->parent);
		sd = sd->parent; /* sd_busy */
		}
		rcu_assign_pointer(per_cpu(sd_busy, cpu), sd);

		rcu_assign_pointer(per_cpu(sd_llc, cpu), sd);
		per_cpu(sd_llc_size, cpu) = size;

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