From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754604Ab2L1TRt (ORCPT ); Fri, 28 Dec 2012 14:17:49 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:55077 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754499Ab2L1TRm (ORCPT ); Fri, 28 Dec 2012 14:17:42 -0500 Message-Id: <20121228190358.332989074@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Fri, 28 Dec 2012 20:05:49 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, "J. Bruce Fields" Subject: [ 139/173] nfsd4: fix oops on unusual readlike compound In-Reply-To: <20121228190330.025298996@decadent.org.uk> X-SA-Exim-Connect-IP: 151.217.219.220 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: "J. Bruce Fields" commit d5f50b0c290431c65377c4afa1c764e2c3fe5305 upstream. If the argument and reply together exceed the maximum payload size, then a reply with a read-like operation can overlow the rq_pages array. Signed-off-by: J. Bruce Fields Signed-off-by: Ben Hutchings --- fs/nfsd/nfs4xdr.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2909,11 +2909,16 @@ nfsd4_encode_read(struct nfsd4_compoundr len = maxcount; v = 0; while (len > 0) { - pn = resp->rqstp->rq_resused++; + pn = resp->rqstp->rq_resused; + if (!resp->rqstp->rq_respages[pn]) { /* ran out of pages */ + maxcount -= len; + break; + } resp->rqstp->rq_vec[v].iov_base = page_address(resp->rqstp->rq_respages[pn]); resp->rqstp->rq_vec[v].iov_len = len < PAGE_SIZE ? len : PAGE_SIZE; + resp->rqstp->rq_resused++; v++; len -= PAGE_SIZE; } @@ -2959,6 +2964,8 @@ nfsd4_encode_readlink(struct nfsd4_compo return nfserr; if (resp->xbuf->page_len) return nfserr_resource; + if (!resp->rqstp->rq_respages[resp->rqstp->rq_resused]) + return nfserr_resource; page = page_address(resp->rqstp->rq_respages[resp->rqstp->rq_resused++]); @@ -3008,6 +3015,8 @@ nfsd4_encode_readdir(struct nfsd4_compou return nfserr; if (resp->xbuf->page_len) return nfserr_resource; + if (!resp->rqstp->rq_respages[resp->rqstp->rq_resused]) + return nfserr_resource; RESERVE_SPACE(8); /* verifier */ savep = p;