[S390] hypfs crashes with invalid mount option.

When an invalid mount option is specified, no root inode is created
for hypfs, hypfs_fill_super() returns with -EINVAL and then
hypfs_kill_super() is called. hypfs_kill_super() does not check if
the root inode has been initialized. This patch adds this check.

Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/arch/s390/hypfs/inode.c b/arch/s390/hypfs/inode.c
index bdcad2ea1ff4..bdade5f2e325 100644
--- a/arch/s390/hypfs/inode.c
+++ b/arch/s390/hypfs/inode.c
@@ -312,10 +312,12 @@ static void hypfs_kill_super(struct super_block *sb)
 {
         struct hypfs_sb_info *sb_info = sb->s_fs_info;
 
-        hypfs_delete_tree(sb->s_root);
-        hypfs_remove(sb_info->update_file);
-        kfree(sb->s_fs_info);
-        sb->s_fs_info = NULL;
+        if (sb->s_root) {
+                hypfs_delete_tree(sb->s_root);
+                hypfs_remove(sb_info->update_file);
+                kfree(sb->s_fs_info);
+                sb->s_fs_info = NULL;
+        }
         kill_litter_super(sb);
 }