NLM: Fix Oops in nlmclnt_mark_reclaim()

 When mixing -olock and -onolock mounts on the same client, we have to
 check that fl->fl_u.nfs_fl.owner is set before dereferencing it.

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/lockd/clntlock.c b/fs/lockd/clntlock.c
index 006bb9e14579..3eaf6e701087 100644
--- a/fs/lockd/clntlock.c
+++ b/fs/lockd/clntlock.c
@@ -157,6 +157,8 @@ void nlmclnt_mark_reclaim(struct nlm_host *host)
                 inode = fl->fl_file->f_dentry->d_inode;
                 if (inode->i_sb->s_magic != NFS_SUPER_MAGIC)
                         continue;
+                if (fl->fl_u.nfs_fl.owner == NULL)
+                        continue;
                 if (fl->fl_u.nfs_fl.owner->host != host)
                         continue;
                 if (!(fl->fl_u.nfs_fl.flags & NFS_LCK_GRANTED))
@@ -226,6 +228,8 @@ restart:
                 inode = fl->fl_file->f_dentry->d_inode;
                 if (inode->i_sb->s_magic != NFS_SUPER_MAGIC)
                         continue;
+                if (fl->fl_u.nfs_fl.owner == NULL)
+                        continue;
                 if (fl->fl_u.nfs_fl.owner->host != host)
                         continue;
                 if (!(fl->fl_u.nfs_fl.flags & NFS_LCK_RECLAIM))