[PATCH] Make sure interleave masks have at least one node set
Otherwise a bad mem policy system call can confuse the interleaving
code into referencing undefined nodes.
Originally reported by Doug Chapman
I was told it's CVE-2005-3358
(one has to love these security people - they make everything sound important)
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index bec88c8..72f402c 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -161,6 +161,10 @@
switch (mode) {
case MPOL_INTERLEAVE:
policy->v.nodes = *nodes;
+ if (nodes_weight(*nodes) == 0) {
+ kmem_cache_free(policy_cache, policy);
+ return ERR_PTR(-EINVAL);
+ }
break;
case MPOL_PREFERRED:
policy->v.preferred_node = first_node(*nodes);