From 701933ac71c4dbfcf7d2111b4ebbfe67ea13d91f Mon Sep 17 00:00:00 2001
From: Miklos Szeredi <mszeredi@redhat.com>
Date: Thu, 12 Nov 2020 11:31:55 +0100
Subject: [PATCH 3/5] ovl: expand warning in ovl_d_real()
References: bsc#1189323
Patch-mainline: v5.11-rc1
Git-commit: cef4cbff06fbc3be54d6d79ee139edecc2ee8598

commit cef4cbff06fbc3be54d6d79ee139edecc2ee8598 upstream.

There was a syzbot report with this warning but insufficient information...

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: David Disseldorp <ddiss@suse.de>
---
 fs/overlayfs/super.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index d6b724beb304..87cf9b1d2eca 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -79,7 +79,7 @@ static void ovl_dentry_release(struct dentry *dentry)
 static struct dentry *ovl_d_real(struct dentry *dentry,
 				 const struct inode *inode)
 {
-	struct dentry *real;
+	struct dentry *real = NULL, *lower;
 
 	/* It's an overlay file */
 	if (inode && d_inode(dentry) == inode)
@@ -98,9 +98,10 @@ static struct dentry *ovl_d_real(struct dentry *dentry,
 	if (real && !inode && ovl_has_upperdata(d_inode(dentry)))
 		return real;
 
-	real = ovl_dentry_lowerdata(dentry);
-	if (!real)
+	lower = ovl_dentry_lowerdata(dentry);
+	if (!lower)
 		goto bug;
+	real = lower;
 
 	/* Handle recursion */
 	real = d_real(real, inode);
@@ -108,8 +109,10 @@ static struct dentry *ovl_d_real(struct dentry *dentry,
 	if (!inode || inode == d_inode(real))
 		return real;
 bug:
-	WARN(1, "ovl_d_real(%pd4, %s:%lu): real dentry not found\n", dentry,
-	     inode ? inode->i_sb->s_id : "NULL", inode ? inode->i_ino : 0);
+	WARN(1, "%s(%pd4, %s:%lu): real dentry (%p/%lu) not found\n",
+	     __func__, dentry, inode ? inode->i_sb->s_id : "NULL",
+	     inode ? inode->i_ino : 0, real,
+	     real && d_inode(real) ? d_inode(real)->i_ino : 0);
 	return dentry;
 }
 
-- 
2.32.0