Subject: [PATCH RFC] NFS & NFSD: Update GSS dependencies
From:   Chuck Lever <cel@kernel.org>
To:     geert@linux-m68k.org
Cc:     linux-nfs@vger.kernel.org
Date:   Wed, 08 Mar 2023 09:45:09 -0500
Message-ID: <167828670993.16253.6476667874038066881.stgit@bazille.1015granger.net>
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From: Chuck Lever <chuck.lever@oracle.com>

Geert reports that:
> On v6.2, "make ARCH=m68k defconfig" gives you
> CONFIG_RPCSEC_GSS_KRB5=m
> On v6.3, it became builtin, due to dropping the dependencies on
> the individual crypto modules.
>
> $ grep -E "CRYPTO_(MD5|DES|CBC|CTS|ECB|HMAC|SHA1|AES)" .config
> CONFIG_CRYPTO_AES=y
> CONFIG_CRYPTO_AES_TI=m
> CONFIG_CRYPTO_DES=m
> CONFIG_CRYPTO_CBC=m
> CONFIG_CRYPTO_CTS=m
> CONFIG_CRYPTO_ECB=m
> CONFIG_CRYPTO_HMAC=m
> CONFIG_CRYPTO_MD5=m
> CONFIG_CRYPTO_SHA1=m

This behavior is triggered by the "default y" in the definition of
RPCSEC_GSS.

The "default y" was added in 2010 by commit df486a25900f ("NFS: Fix
the selection of security flavours in Kconfig"). However,
svc_gss_principal was removed in 2012 by commit 03a4e1f6ddf2
("nfsd4: move principal name into svc_cred"), so the 2010 fix is
no longer necessary. We can safely change the NFS_V4 and NFSD_V4
dependencies back to RPCSEC_GSS_KRB5 to get the nicer v6.2
behavior back.

Selecting KRB5 symbolically represents the true requirement here:
that all spec-compliant NFSv4 implementations must have Kerberos
available to use.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 fs/nfs/Kconfig  |    2 +-
 fs/nfsd/Kconfig |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig
index 14a72224b657..450d6c3bc05e 100644
--- a/fs/nfs/Kconfig
+++ b/fs/nfs/Kconfig
@@ -75,7 +75,7 @@ config NFS_V3_ACL
 config NFS_V4
 	tristate "NFS client support for NFS version 4"
 	depends on NFS_FS
-	select SUNRPC_GSS
+	select RPCSEC_GSS_KRB5
 	select KEYS
 	help
 	  This option enables support for version 4 of the NFS protocol
diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig
index 7c441f2bd444..43b88eaf0673 100644
--- a/fs/nfsd/Kconfig
+++ b/fs/nfsd/Kconfig
@@ -73,7 +73,7 @@ config NFSD_V4
 	bool "NFS server support for NFS version 4"
 	depends on NFSD && PROC_FS
 	select FS_POSIX_ACL
-	select SUNRPC_GSS
+	select RPCSEC_GSS_KRB5
 	select CRYPTO
 	select CRYPTO_MD5
 	select CRYPTO_SHA256