From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Weston Andros Adamson , "J. Bruce Fields" , Anna Schumaker Subject: [PATCH 4.4 82/91] NFSv4: fix getacl ERANGE for some ACL buffer sizes Date: Fri, 10 Mar 2017 10:09:21 +0100 Message-Id: <20170310083904.884120426@linuxfoundation.org> In-Reply-To: <20170310083900.730556986@linuxfoundation.org> References: <20170310083900.730556986@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Weston Andros Adamson commit ed92d8c137b7794c2c2aa14479298b9885967607 upstream. We're not taking into account that the space needed for the (variable length) attr bitmap, with the result that we'd sometimes get a spurious ERANGE when the ACL data got close to the end of a page. Just add in an extra page to make sure. Signed-off-by: Weston Andros Adamson Signed-off-by: J. Bruce Fields Signed-off-by: Anna Schumaker Signed-off-by: Greg Kroah-Hartman --- fs/nfs/nfs4proc.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -4711,7 +4711,7 @@ out: */ static ssize_t __nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t buflen) { - struct page *pages[NFS4ACL_MAXPAGES] = {NULL, }; + struct page *pages[NFS4ACL_MAXPAGES + 1] = {NULL, }; struct nfs_getaclargs args = { .fh = NFS_FH(inode), .acl_pages = pages, @@ -4725,13 +4725,9 @@ static ssize_t __nfs4_get_acl_uncached(s .rpc_argp = &args, .rpc_resp = &res, }; - unsigned int npages = DIV_ROUND_UP(buflen, PAGE_SIZE); + unsigned int npages = DIV_ROUND_UP(buflen, PAGE_SIZE) + 1; int ret = -ENOMEM, i; - /* As long as we're doing a round trip to the server anyway, - * let's be prepared for a page of acl data. */ - if (npages == 0) - npages = 1; if (npages > ARRAY_SIZE(pages)) return -ERANGE;