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Commit 12ee3c0a authored by David Rientjes's avatar David Rientjes Committed by Greg Kroah-Hartman
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driver core: numa: fix BUILD_BUG_ON for node_read_distance 



node_read_distance() has a BUILD_BUG_ON() to prevent buffer overruns when
the number of nodes printed will exceed the buffer length.

Each node only needs four chars: three for distance (maximum distance is
255) and one for a seperating space or a trailing newline.

Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent f0eae0ed

drivers/base/node.c

+5 −2
Original line number Diff line number Diff line
@@ -165,8 +165,11 @@ static ssize_t node_read_distance(struct sys_device * dev, 
	int len = 0;

	int i;



	/* buf currently PAGE_SIZE, need ~4 chars per node */

	BUILD_BUG_ON(MAX_NUMNODES*4 > PAGE_SIZE/2);

	/*

	 * buf is currently PAGE_SIZE in length and each node needs 4 chars

	 * at the most (distance + space or newline).

	 */

	BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);



	for_each_online_node(i)

		len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i));