From: Jeff Layton Date: Fri, 4 May 2012 15:44:12 +0000 (-0400) Subject: sunrpc: do array overrun check in svc_recv before allocating pages X-Git-Tag: v3.5-rc1~18^2~39 X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=91c427ac3a61ccabae0fdef53563edf40394b6c9;p=~emulex%2Finfiniband.git 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 Signed-off-by: J. Bruce Fields --- diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index 4bda09d7e1a..8195c6acba1 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -601,6 +601,7 @@ int svc_recv(struct svc_rqst *rqstp, long timeout) /* 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 @@ int svc_recv(struct svc_rqst *rqstp, long timeout) 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;