From: Greg KH <gregkh@linuxfoundation.org>
Date: Mon, 30 Mar 2015 12:59:15 +0000 (+0200)
Subject: debugfs: allow bad parent pointers to be passed in
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=c9e15f25f514a76d906be01e621f400cdee94558;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

debugfs: allow bad parent pointers to be passed in

If something went wrong with creating a debugfs file/symlink/directory,
that value could be passed down into debugfs again as a parent dentry.
To make caller code simpler, just error out if this happens, and don't
crash the kernel.

Reported-by: Alex Elder <elder@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Alex Elder <elder@linaro.org>
---

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 96400ab42d13..61e72d44cf94 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -254,6 +254,9 @@ static struct dentry *start_creating(const char *name, struct dentry *parent)
 
 	pr_debug("debugfs: creating file '%s'\n",name);
 
+	if (IS_ERR(parent))
+		return parent;
+
 	error = simple_pin_fs(&debug_fs_type, &debugfs_mount,
 			      &debugfs_mount_count);
 	if (error)