Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx1.redhat.com ([209.132.183.28]:59789 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752814AbaDDOB1 (ORCPT ); Fri, 4 Apr 2014 10:01:27 -0400 Date: Fri, 4 Apr 2014 10:01:24 -0400 From: Jeff Layton To: Trond Myklebust Cc: linux-nfs@vger.kernel.org, lmcilroy@redhat.com Subject: Re: [PATCH] nfs: don't pass non-NULL-terminated string to pr_notice() Message-ID: <20140404100124.2db49cb8@tlielax.poochiereds.net> In-Reply-To: <5EC0B3CC-6647-4A6E-A44C-82A72CBEC490@primarydata.com> References: <1396605654-10108-1-git-send-email-jlayton@redhat.com> <5EC0B3CC-6647-4A6E-A44C-82A72CBEC490@primarydata.com> MIME-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Sender: linux-nfs-owner@vger.kernel.org List-ID: On Fri, 4 Apr 2014 09:51:11 -0400 Trond Myklebust wrote: > > On Apr 4, 2014, at 6:00, Jeff Layton wrote: > > > There is no guarantee that the strings in the nfs_cache_array will be > > NULL-terminated. In the event that we end up hitting a readdir loop, we > > need to ensure that we pass the warning message a properly-terminated > > string. > > > > Reported-by: Lachlan McIlroy > > Signed-off-by: Jeff Layton > > --- > > fs/nfs/dir.c | 7 ++++--- > > 1 file changed, 4 insertions(+), 3 deletions(-) > > > > diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c > > index 5c0b6ecc3a88..4689b125f9fe 100644 > > --- a/fs/nfs/dir.c > > +++ b/fs/nfs/dir.c > > @@ -304,12 +304,13 @@ int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_des > > if (ctx->duped > 0 > > && ctx->dup_cookie == *desc->dir_cookie) { > > if (printk_ratelimit()) { > > + char *name = kstrndup(array->array[i].string.name, array->array[i].string.len, GFP_KERNEL); > > + > > pr_notice("NFS: directory %pD2 contains a readdir loop." > > "Please contact your server vendor. " > > "The file: %s has duplicate cookie %llu\n", > > - desc->file, > > - array->array[i].string.name, > > - *desc->dir_cookie); > > + desc->file, name, *desc->dir_cookie); > > + kfree(name); > > } > > Umm? Any reason why we couldn?t just use ?%.*s? ? > No reason at all. I had never run across that... I'll respin and repost -- thanks! -- Jeff Layton