From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5691F302177 for ; Mon, 13 Oct 2025 10:47:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760352435; cv=none; b=r/bqRmBp6ihcGJ31spZG/PqFHXxDF//rjCxrTVoG9TATcjvdoVACs+gMjY4dk91pk0Yr60+3eGYcXgyre36YQxVaV8pp9eHttu6PJ57WfSDOpfxD2sVH6BZg1ULWKD5WF6JdFjVFhqVcgfm0A4YPZLTohqcoKtiv1vn4uetNP6Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760352435; c=relaxed/simple; bh=gA8bxpzXimzb54QzB2Y7mbFZjhMeRaVdNxwhzfiamcc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=o7ZPutpCm9G0RtM0l0sVhWdoH31XVK2n1kpKfxWdTkYLBXNncPy3vBYEYEog1PtemtauoliFFk4U7YZZQVPOKoxWVKd4Z8lcB5gcA1+VBrXJ4lBLX6Ap2j9khtKvZoIK8Q/PAxWPZaRPx3zkt47j99Zi48woZlHasItiVZFMgpY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=RYr6Vd18; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="RYr6Vd18" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1760352425; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=QdhIzPNclHC5KxVipZI/m9MoIOqoEgSAZQcCWFA6mvM=; b=RYr6Vd18sd4f/w6vwAOmLvl0v/LcSRQEgfFLAtQHbzBOMruhdDBtPa5MAaE8/0StLVOfH3 7afRe/ABTBa69lj3p6gIxGCpR14EjsWIT1LbEJcQnSszjZuJRFcbAA7yRi2QB9nAbe9UZ3 Sy7NHxYuYyraq2CFiioSgsEEa2RU7Wk= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-68-DWM-IO-2P4mVBgX2LZtp4w-1; Mon, 13 Oct 2025 06:47:02 -0400 X-MC-Unique: DWM-IO-2P4mVBgX2LZtp4w-1 X-Mimecast-MFC-AGG-ID: DWM-IO-2P4mVBgX2LZtp4w_1760352421 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id BB5941800372; Mon, 13 Oct 2025 10:47:00 +0000 (UTC) Received: from aion.redhat.com (unknown [10.22.80.4]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 0AB6E180141C; Mon, 13 Oct 2025 10:47:00 +0000 (UTC) Received: by aion.redhat.com (Postfix, from userid 1000) id 586194B1B7D; Mon, 13 Oct 2025 06:46:58 -0400 (EDT) Date: Mon, 13 Oct 2025 06:46:58 -0400 From: Scott Mayhew To: Chuck Lever Cc: Eric Biggers , Jeff Layton , NeilBrown , Olga Kornievskaia , Dai Ngo , Tom Talpey , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org Subject: Re: [PATCH] nfsd: Use MD5 library instead of crypto_shash Message-ID: References: <20251011185225.155625-1-ebiggers@kernel.org> <5f405581-e7e2-4e77-8044-0496db85aa27@oracle.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5f405581-e7e2-4e77-8044-0496db85aa27@oracle.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 On Sun, 12 Oct 2025, Chuck Lever wrote: > On 10/11/25 2:52 PM, Eric Biggers wrote: > > Update NFSD's support for "legacy client tracking" (which uses MD5) to > > use the MD5 library instead of crypto_shash. This has several benefits: > > > > - Simpler code. Notably, much of the error-handling code is no longer > > needed, since the library functions can't fail. > > > > - Improved performance due to reduced overhead. A microbenchmark of > > nfs4_make_rec_clidname() shows a speedup from 1455 cycles to 425. > > > > - The MD5 code can now safely be built as a loadable module when nfsd is > > built as a loadable module. (Previously, nfsd forced the MD5 code to > > built-in, presumably to work around the unreliablity of the name-based > > loading.) Thus, select MD5 from the tristate option NFSD if > > NFSD_LEGACY_CLIENT_TRACKING, instead of from the bool option NFSD_V4. > > > > To preserve the existing behavior of legacy client tracking support > > being disabled when the kernel is booted with "fips=1", make > > nfsd4_legacy_tracking_init() return an error if fips_enabled. I don't > > know if this is truly needed, but it preserves the existing behavior. > > > > Signed-off-by: Eric Biggers > > No objection, but let's cross our t's and dot our i's. Scott, when you > have recovered from bake-a-thon, can you have a look at this one? > > Thanks! Looks fine to me. Reviewed-by: Scott Mayhew I agree with Jeff - it would be nice to just remove the legacy tracking. I'm guessing it's still used in smaller/embedded setups? RHEL and Fedora haven't had it enabled for years. Looking at a few other distros... it's not enabled in OpenSUSE Leap or Tumbleweed. It's not enabled in Debian Sid (but it is enabled in Trixie). -Scott > > > > --- > > fs/nfsd/Kconfig | 3 +- > > fs/nfsd/nfs4recover.c | 82 ++++++++----------------------------------- > > 2 files changed, 16 insertions(+), 69 deletions(-) > > > > diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig > > index e134dce45e350..380a4caa33a73 100644 > > --- a/fs/nfsd/Kconfig > > +++ b/fs/nfsd/Kconfig > > @@ -3,10 +3,11 @@ config NFSD > > tristate "NFS server support" > > depends on INET > > depends on FILE_LOCKING > > depends on FSNOTIFY > > select CRC32 > > + select CRYPTO_LIB_MD5 if NFSD_LEGACY_CLIENT_TRACKING > > select CRYPTO_LIB_SHA256 if NFSD_V4 > > select LOCKD > > select SUNRPC > > select EXPORTFS > > select NFS_COMMON > > @@ -75,12 +76,10 @@ config NFSD_V3_ACL > > config NFSD_V4 > > bool "NFS server support for NFS version 4" > > depends on NFSD && PROC_FS > > select FS_POSIX_ACL > > select RPCSEC_GSS_KRB5 > > - select CRYPTO > > - select CRYPTO_MD5 > > select GRACE_PERIOD > > select NFS_V4_2_SSC_HELPER if NFS_V4_2 > > help > > This option enables support in your system's NFS server for > > version 4 of the NFS protocol (RFC 3530). > > diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c > > index e2b9472e5c78c..dbc0aecef95e3 100644 > > --- a/fs/nfsd/nfs4recover.c > > +++ b/fs/nfsd/nfs4recover.c > > @@ -30,13 +30,14 @@ > > * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS > > * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. > > * > > */ > > > > -#include > > +#include > > #include > > #include > > +#include > > #include > > #include > > #include > > #include > > #include > > @@ -90,61 +91,22 @@ static void > > nfs4_reset_creds(const struct cred *original) > > { > > put_cred(revert_creds(original)); > > } > > > > -static int > > +static void > > nfs4_make_rec_clidname(char dname[HEXDIR_LEN], const struct xdr_netobj *clname) > > { > > u8 digest[MD5_DIGEST_SIZE]; > > - struct crypto_shash *tfm; > > - int status; > > > > dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n", > > clname->len, clname->data); > > - tfm = crypto_alloc_shash("md5", 0, 0); > > - if (IS_ERR(tfm)) { > > - status = PTR_ERR(tfm); > > - goto out_no_tfm; > > - } > > > > - status = crypto_shash_tfm_digest(tfm, clname->data, clname->len, > > - digest); > > - if (status) > > - goto out; > > + md5(clname->data, clname->len, digest); > > > > static_assert(HEXDIR_LEN == 2 * MD5_DIGEST_SIZE + 1); > > sprintf(dname, "%*phN", MD5_DIGEST_SIZE, digest); > > - > > - status = 0; > > -out: > > - crypto_free_shash(tfm); > > -out_no_tfm: > > - return status; > > -} > > - > > -/* > > - * If we had an error generating the recdir name for the legacy tracker > > - * then warn the admin. If the error doesn't appear to be transient, > > - * then disable recovery tracking. > > - */ > > -static void > > -legacy_recdir_name_error(struct nfs4_client *clp, int error) > > -{ > > - printk(KERN_ERR "NFSD: unable to generate recoverydir " > > - "name (%d).\n", error); > > - > > - /* > > - * if the algorithm just doesn't exist, then disable the recovery > > - * tracker altogether. The crypto libs will generally return this if > > - * FIPS is enabled as well. > > - */ > > - if (error == -ENOENT) { > > - printk(KERN_ERR "NFSD: disabling legacy clientid tracking. " > > - "Reboot recovery will not function correctly!\n"); > > - nfsd4_client_tracking_exit(clp->net); > > - } > > } > > > > static void > > __nfsd4_create_reclaim_record_grace(struct nfs4_client *clp, > > const char *dname, int len, struct nfsd_net *nn) > > @@ -180,13 +142,11 @@ nfsd4_create_clid_dir(struct nfs4_client *clp) > > if (test_and_set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) > > return; > > if (!nn->rec_file) > > return; > > > > - status = nfs4_make_rec_clidname(dname, &clp->cl_name); > > - if (status) > > - return legacy_recdir_name_error(clp, status); > > + nfs4_make_rec_clidname(dname, &clp->cl_name); > > > > status = nfs4_save_creds(&original_cred); > > if (status < 0) > > return; > > > > @@ -374,13 +334,11 @@ nfsd4_remove_clid_dir(struct nfs4_client *clp) > > struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id); > > > > if (!nn->rec_file || !test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) > > return; > > > > - status = nfs4_make_rec_clidname(dname, &clp->cl_name); > > - if (status) > > - return legacy_recdir_name_error(clp, status); > > + nfs4_make_rec_clidname(dname, &clp->cl_name); > > > > status = mnt_want_write_file(nn->rec_file); > > if (status) > > goto out; > > clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags); > > @@ -601,10 +559,15 @@ nfsd4_legacy_tracking_init(struct net *net) > > if (net != &init_net) { > > pr_warn("NFSD: attempt to initialize legacy client tracking in a container ignored.\n"); > > return -EINVAL; > > } > > > > + if (fips_enabled) { > > + pr_warn("NFSD: legacy client tracking is disabled due to FIPS\n"); > > + return -EINVAL; > > + } > > + > > status = nfs4_legacy_state_init(net); > > if (status) > > return status; > > > > status = nfsd4_load_reboot_recovery_data(net); > > @@ -657,25 +620,20 @@ nfs4_recoverydir(void) > > } > > > > static int > > nfsd4_check_legacy_client(struct nfs4_client *clp) > > { > > - int status; > > char dname[HEXDIR_LEN]; > > struct nfs4_client_reclaim *crp; > > struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id); > > struct xdr_netobj name; > > > > /* did we already find that this client is stable? */ > > if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) > > return 0; > > > > - status = nfs4_make_rec_clidname(dname, &clp->cl_name); > > - if (status) { > > - legacy_recdir_name_error(clp, status); > > - return status; > > - } > > + nfs4_make_rec_clidname(dname, &clp->cl_name); > > > > /* look for it in the reclaim hashtable otherwise */ > > name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL); > > if (!name.data) { > > dprintk("%s: failed to allocate memory for name.data!\n", > > @@ -1264,17 +1222,14 @@ nfsd4_cld_check(struct nfs4_client *clp) > > if (crp) > > goto found; > > > > #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING > > if (nn->cld_net->cn_has_legacy) { > > - int status; > > char dname[HEXDIR_LEN]; > > struct xdr_netobj name; > > > > - status = nfs4_make_rec_clidname(dname, &clp->cl_name); > > - if (status) > > - return -ENOENT; > > + nfs4_make_rec_clidname(dname, &clp->cl_name); > > > > name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL); > > if (!name.data) { > > dprintk("%s: failed to allocate memory for name.data!\n", > > __func__); > > @@ -1315,15 +1270,12 @@ nfsd4_cld_check_v2(struct nfs4_client *clp) > > > > #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING > > if (cn->cn_has_legacy) { > > struct xdr_netobj name; > > char dname[HEXDIR_LEN]; > > - int status; > > > > - status = nfs4_make_rec_clidname(dname, &clp->cl_name); > > - if (status) > > - return -ENOENT; > > + nfs4_make_rec_clidname(dname, &clp->cl_name); > > > > name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL); > > if (!name.data) { > > dprintk("%s: failed to allocate memory for name.data\n", > > __func__); > > @@ -1692,15 +1644,11 @@ nfsd4_cltrack_legacy_recdir(const struct xdr_netobj *name) > > /* just return nothing if output will be truncated */ > > kfree(result); > > return NULL; > > } > > > > - copied = nfs4_make_rec_clidname(result + copied, name); > > - if (copied) { > > - kfree(result); > > - return NULL; > > - } > > + nfs4_make_rec_clidname(result + copied, name); > > > > return result; > > } > > > > static char * > > > > base-commit: 0739473694c4878513031006829f1030ec850bc2 > > > -- > Chuck Lever >