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

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@ms2.inr.ac.ru>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/ipc/util.c b/ipc/util.c
index 5e785a2..b3dcfad 100644 (file)
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -183,8 +183,7 @@ static int grow_ary(struct ipc_ids* ids, int newsize)
        if(new == NULL)
                return size;
        new->size = newsize;
        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;
        }
        for(i=size;i<newsize;i++) {
                new->p[i] = NULL;
        }