fat: fix d_revalidate oopsen on NFS exports

can't blindly check nd->flags in ->d_revalidate()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index f88f752babd9..adae3fb7451a 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -43,7 +43,7 @@ static int vfat_revalidate_shortname(struct dentry *dentry)
 
 static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
-        if (nd->flags & LOOKUP_RCU)
+        if (nd && nd->flags & LOOKUP_RCU)
                 return -ECHILD;
 
         /* This is not negative dentry. Always valid. */
@@ -54,7 +54,7 @@ static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd)
 
 static int vfat_revalidate_ci(struct dentry *dentry, struct nameidata *nd)
 {
-        if (nd->flags & LOOKUP_RCU)
+        if (nd && nd->flags & LOOKUP_RCU)
                 return -ECHILD;
 
         /*