From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
[ Upstream commit 37ea7b630ae5cdea4e8ff381d9d23abfef5939e6 ]
Lots of callers of debugfs_lookup() were just checking NULL to see if
the file/directory was found or not. By changing this in ff9fb72bc077
("debugfs: return error values, not NULL") we caused some subsystems to
easily crash.
Fixes: ff9fb72bc077 ("debugfs: return error values, not NULL")
Reported-by: syzbot+b382ba6a802a3d242790@xxxxxxxxxxxxxxxxxxxxxxxxx
Reported-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Omar Sandoval <osandov@xxxxxx>
Cc: Jens Axboe <axboe@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/debugfs/inode.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 0bbe2df9077c6..377aec4ddab64 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -252,8 +252,8 @@ MODULE_ALIAS_FS("debugfs");
* @parent: a pointer to the parent dentry of the file.
*
* This function will return a pointer to a dentry if it succeeds. If the file
- * doesn't exist or an error occurs, %ERR_PTR(-ERROR) will be returned. The
- * returned dentry must be passed to dput() when it is no longer needed.
+ * doesn't exist or an error occurs, %NULL will be returned. The returned
+ * dentry must be passed to dput() when it is no longer needed.
*
* If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned.
@@ -263,7 +263,7 @@ struct dentry *debugfs_lookup(const char *name, struct dentry *parent)
struct dentry *dentry;
if (IS_ERR(parent))
- return parent;
+ return NULL;
if (!parent)
parent = debugfs_mount->mnt_root;
@@ -273,10 +273,10 @@ struct dentry *debugfs_lookup(const char *name, struct dentry *parent)
inode_unlock(d_inode(parent));
if (IS_ERR(dentry))
- return dentry;
+ return NULL;
if (!d_really_is_positive(dentry)) {
dput(dentry);
- return ERR_PTR(-EINVAL);
+ return NULL;
}
return dentry;
}
--
2.19.1
