[PATCH 4.19 069/106] hypfs: Fix error number left in struct pointer member

From: Greg Kroah-Hartman
Date: Sun Oct 06 2019 - 13:59:13 EST


From: David Howells <dhowells@xxxxxxxxxx>

[ Upstream commit b54c64f7adeb241423cd46598f458b5486b0375e ]

In hypfs_fill_super(), if hypfs_create_update_file() fails,
sbi->update_file is left holding an error number. This is passed to
hypfs_kill_super() which doesn't check for this.

Fix this by not setting sbi->update_value until after we've checked for
error.

Fixes: 24bbb1faf3f0 ("[PATCH] s390_hypfs filesystem")
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
cc: linux-s390@xxxxxxxxxxxxxxx
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/s390/hypfs/inode.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/s390/hypfs/inode.c b/arch/s390/hypfs/inode.c
index c681329fdeec6..e4d17d9ea93d8 100644
--- a/arch/s390/hypfs/inode.c
+++ b/arch/s390/hypfs/inode.c
@@ -269,7 +269,7 @@ static int hypfs_show_options(struct seq_file *s, struct dentry *root)
static int hypfs_fill_super(struct super_block *sb, void *data, int silent)
{
struct inode *root_inode;
- struct dentry *root_dentry;
+ struct dentry *root_dentry, *update_file;
int rc = 0;
struct hypfs_sb_info *sbi;

@@ -300,9 +300,10 @@ static int hypfs_fill_super(struct super_block *sb, void *data, int silent)
rc = hypfs_diag_create_files(root_dentry);
if (rc)
return rc;
- sbi->update_file = hypfs_create_update_file(root_dentry);
- if (IS_ERR(sbi->update_file))
- return PTR_ERR(sbi->update_file);
+ update_file = hypfs_create_update_file(root_dentry);
+ if (IS_ERR(update_file))
+ return PTR_ERR(update_file);
+ sbi->update_file = update_file;
hypfs_update_update(sb);
pr_info("Hypervisor filesystem mounted\n");
return 0;
--
2.20.1