[PATCH] IPC: access to unmapped vmalloc area in grow_ary()

From: Kirill Korotaev
Date: Mon Apr 17 2006 - 07:34:01 EST


grow_ary() should not copy struct ipc_id_ary (it copies new->p, not new). Due to this, memcpy() src pointer could hit unmapped vmalloc page when near page boundary.

Found during OpenVZ stress testing

Signed-Off-By: Alexey Kuznetsov <kuznet@xxxxxxxxxxxxx>
Signed-Off-By: Kirill Korotaev <dev@xxxxxxxxxx>
diff -urp ../git/linux-2.6.16-workgpl/ipc/util.c linux-2.6.16/ipc/util.c
--- ../git/linux-2.6.16-workgpl/ipc/util.c 2006-04-13 16:01:47.000000000 +0400
+++ linux-2.6.16/ipc/util.c 2006-04-13 16:01:05.000000000 +0400
@@ -187,8 +187,7 @@ static int grow_ary(struct ipc_ids* ids,
if(new == NULL)
return size;
new->size = newsize;
- memcpy(new->p, ids->entries->p, sizeof(struct kern_ipc_perm *)*size +
- sizeof(struct ipc_id_ary));
+ memcpy(new->p, ids->entries->p, sizeof(struct kern_ipc_perm *)*size);
for(i=size;i<newsize;i++) {
new->p[i] = NULL;
}