From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933119Ab2ILXve (ORCPT ); Wed, 12 Sep 2012 19:51:34 -0400 Received: from mail-ob0-f174.google.com ([209.85.214.174]:49817 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933384Ab2ILXoN (ORCPT ); Wed, 12 Sep 2012 19:44:13 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg KH , "J. Bruce Fields" Subject: [ 20/46] svcrpc: fix BUG() in svc_tcp_clear_pages Date: Wed, 12 Sep 2012 16:39:10 -0700 Message-Id: <20120912233819.777174328@linuxfoundation.org> X-Mailer: git-send-email 1.7.10.1.362.g242cab3 In-Reply-To: <20120912233817.662663809@linuxfoundation.org> References: <20120912233817.662663809@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greg KH 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: "J. Bruce Fields" commit be1e44441a560c43c136a562d49a1c9623c91197 upstream. Examination of svc_tcp_clear_pages shows that it assumes sk_tcplen is consistent with sk_pages[] (in particular, sk_pages[n] can't be NULL if sk_tcplen would lead us to expect n pages of data). svc_tcp_restore_pages zeroes out sk_pages[] while leaving sk_tcplen. This is OK, since both functions are serialized by XPT_BUSY. However, that means the inconsistency must be repaired before dropping XPT_BUSY. Therefore we should be ensuring that svc_tcp_save_pages repairs the problem before exiting svc_tcp_recv_record on error. Symptoms were a BUG() in svc_tcp_clear_pages. Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman --- net/sunrpc/svcsock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -1122,9 +1122,9 @@ static int svc_tcp_recvfrom(struct svc_r if (len >= 0) svsk->sk_tcplen += len; if (len != want) { + svc_tcp_save_pages(svsk, rqstp); if (len < 0 && len != -EAGAIN) goto err_other; - svc_tcp_save_pages(svsk, rqstp); dprintk("svc: incomplete TCP record (%d of %d)\n", svsk->sk_tcplen, svsk->sk_reclen); goto err_noclose;