[PATCH AUTOSEL 3.18 17/61] nfsd4: fix crash on writing v4_end_grace before nfsd startup

[PATCH AUTOSEL 3.18 17/61] nfsd4: fix crash on writing v4_end_grace before nfsd startup

[Sasha Levin]

From: "J. Bruce Fields" <bfields@redhat.com>

[ Upstream commit 62a063b8e7d1db684db3f207261a466fa3194e72 ]

Anatoly Trosinenko reports that this:

1) Checkout fresh master Linux branch (tested with commit e195ca6cb)
2) Copy x84_64-config-4.14 to .config, then enable NFS server v4 and build
3) From `kvm-xfstests shell`:

results in NULL dereference in locks_end_grace.

Check that nfsd has been started before trying to end the grace period.

Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/nfsd/nfsctl.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index ca73ca79a0ee..0e8574af298b 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -1110,6 +1110,8 @@ static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size)
 		case 'Y':
 		case 'y':
 		case '1':
+			if (nn->nfsd_serv)
+				return -EBUSY;
 			nfsd4_end_grace(nn);
 			break;
 		default:
-- 
2.19.1

[PATCH AUTOSEL 3.18 46/61] NFS: nfs_compare_mount_options always compare auth flavors.

[Sasha Levin]

From: Chris Perl <cperl@janestreet.com>

[ Upstream commit 594d1644cd59447f4fceb592448d5cd09eb09b5e ]

This patch removes the check from nfs_compare_mount_options to see if a
`sec' option was passed for the current mount before comparing auth
flavors and instead just always compares auth flavors.

Consider the following scenario:

You have a server with the address 192.168.1.1 and two exports /export/a
and /export/b.  The first export supports `sys' and `krb5' security, the
second just `sys'.

Assume you start with no mounts from the server.

The following results in EIOs being returned as the kernel nfs client
incorrectly thinks it can share the underlying `struct nfs_server's:

$ mkdir /tmp/{a,b}
$ sudo mount -t nfs -o vers=3,sec=krb5 192.168.1.1:/export/a /tmp/a
$ sudo mount -t nfs -o vers=3          192.168.1.1:/export/b /tmp/b
$ df >/dev/null
df: ‘/tmp/b’: Input/output error

Signed-off-by: Chris Perl <cperl@janestreet.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/nfs/super.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index dbdc2d2f91cf..655ac3a196e4 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2376,8 +2376,7 @@ static int nfs_compare_mount_options(const struct super_block *s, const struct n
 		goto Ebusy;
 	if (a->acdirmax != b->acdirmax)
 		goto Ebusy;
-	if (b->auth_info.flavor_len > 0 &&
-	   clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
+	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
 		goto Ebusy;
 	return 1;
 Ebusy:
-- 
2.19.1