sunrpc: do array overrun check in svc_recv before allocating pages
There's little point in waiting until after we allocate all of the pages
to see if we're going to overrun the array. In the event that this
calculation is really off we could end up scribbling over a bunch of
memory and make it tougher to debug.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 4bda09d..8195c6a 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -601,6 +601,7 @@
/* now allocate needed pages. If we get a failure, sleep briefly */
pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE;
+ BUG_ON(pages >= RPCSVC_MAXPAGES);
for (i = 0; i < pages ; i++)
while (rqstp->rq_pages[i] == NULL) {
struct page *p = alloc_page(GFP_KERNEL);
@@ -615,7 +616,6 @@
rqstp->rq_pages[i] = p;
}
rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */
- BUG_ON(pages >= RPCSVC_MAXPAGES);
/* Make arg->head point to first page and arg->pages point to rest */
arg = &rqstp->rq_arg;