x86/numa: Add constraints check for nid parameters

This patch adds constraint checks to the numa_set_distance()
function.

When the check triggers (this should not happen normally) it
emits a warning and avoids a store to a negative index in
numa_distance[] array - i.e. avoids memory corruption.

Negative ids can be passed when the pxm-to-nids mapping is not
properly filled while parsing the SRAT.

Signed-off-by: Petr Holasek <pholasek@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Anton Arapov <anton@redhat.com>
Link: http://lkml.kernel.org/r/20111208121640.GA2229@dhcp-27-244.brq.redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Petr Holasek 2011-12-08 13:16:41 +01:00 committed by Ingo Molnar
parent 54c29c635a
commit 54eed6cb16

View file

@ -430,8 +430,9 @@ static int __init numa_alloc_distance(void)
* calls are ignored until the distance table is reset with
* numa_reset_distance().
*
* If @from or @to is higher than the highest known node at the time of
* table creation or @distance doesn't make sense, the call is ignored.
* If @from or @to is higher than the highest known node or lower than zero
* at the time of table creation or @distance doesn't make sense, the call
* is ignored.
* This is to allow simplification of specific NUMA config implementations.
*/
void __init numa_set_distance(int from, int to, int distance)
@ -439,8 +440,9 @@ void __init numa_set_distance(int from, int to, int distance)
if (!numa_distance && numa_alloc_distance() < 0)
return;
if (from >= numa_distance_cnt || to >= numa_distance_cnt) {
printk_once(KERN_DEBUG "NUMA: Debug: distance out of bound, from=%d to=%d distance=%d\n",
if (from >= numa_distance_cnt || to >= numa_distance_cnt ||
from < 0 || to < 0) {
pr_warn_once("NUMA: Warning: node ids are out of bound, from=%d to=%d distance=%d\n",
from, to, distance);
return;
}