From: Patrick Steinhardt <ps@pks.im>
Date: Wed, 4 Dec 2019 07:13:22 +0100
Subject: [PATCH] nfsd: depend on CRYPTO_MD5 for legacy client tracking
Git-commit: 38a2204f5298620e8a1c3b1dc7b831425106dbc0
Patch-mainline: v5.5-rc1
References: git-fixes

The legacy client tracking infrastructure of nfsd makes use of MD5 to
derive a client's recovery directory name. As the nfsd module doesn't
declare any dependency on CRYPTO_MD5, though, it may fail to allocate
the hash if the kernel was compiled without it. As a result, generation
of client recovery directories will fail with the following error:

    NFSD: unable to generate recoverydir name

The explicit dependency on CRYPTO_MD5 was removed as redundant back in
6aaa67b5f3b9 (NFSD: Remove redundant "select" clauses in fs/Kconfig
2008-02-11) as it was already implicitly selected via RPCSEC_GSS_KRB5.
This broke when RPCSEC_GSS_KRB5 was made optional for NFSv4 in commit
df486a25900f (NFS: Fix the selection of security flavours in Kconfig) at
a later point.

Fix the issue by adding back an explicit dependency on CRYPTO_MD5.

Fixes: df486a25900f (NFS: Fix the selection of security flavours in Kconfig)
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: NeilBrown <neilb@suse.com>

---
 fs/nfsd/Kconfig |    1 +
 1 file changed, 1 insertion(+)

--- a/fs/nfsd/Kconfig
+++ b/fs/nfsd/Kconfig
@@ -72,6 +72,7 @@ config NFSD_V4
 	select NFSD_V3
 	select FS_POSIX_ACL
 	select SUNRPC_GSS
+	select CRYPTO_MD5
 	select CRYPTO
 	select GRACE_PERIOD
 	help