From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from fieldses.org ([174.143.236.118]:57586 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751212Ab1CYDMm (ORCPT ); Thu, 24 Mar 2011 23:12:42 -0400 Date: Thu, 24 Mar 2011 23:12:40 -0400 To: linux-nfs@vger.kernel.org Cc: Neil Brown Subject: [PATCH] nfsd: fix auth_domain reference leak on nlm operations Message-ID: <20110325031240.GA6479@fieldses.org> Content-Type: text/plain; charset=us-ascii From: "J. Bruce Fields" Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Well, that one was fun to track down.... And how did it manage to lurk for nearly 10 years? --b. commit 38069804ed036adbf23aa94eafd5400c4f92fe6b Author: J. Bruce Fields Date: Thu Mar 24 22:51:14 2011 -0400 nfsd: fix auth_domain reference leak on nlm operations This was noticed by users who performed more than 2^32 lock operations and hence made this counter overflow (eventually leading to use-after-free's). Setting rq_client to NULL here means that it won't later get auth_domain_put() when it should be. Appears to have been introduced in 2.5.42 by "[PATCH] kNFSd: Move auth domain lookup into svcauth" which moved most of the rq_client handling to common svcauth code, but left behind this one line. Cc: Neil Brown Cc: stable@kernel.org Signed-off-by: J. Bruce Fields diff --git a/fs/nfsd/lockd.c b/fs/nfsd/lockd.c index 0c6d816..7c831a2 100644 --- a/fs/nfsd/lockd.c +++ b/fs/nfsd/lockd.c @@ -38,7 +38,6 @@ nlm_fopen(struct svc_rqst *rqstp, struct nfs_fh *f, struct file **filp) exp_readlock(); nfserr = nfsd_open(rqstp, &fh, S_IFREG, NFSD_MAY_LOCK, filp); fh_put(&fh); - rqstp->rq_client = NULL; exp_readunlock(); /* We return nlm error codes as nlm doesn't know * about nfsd, but nfsd does know about nlm..