[PATCH] ovl: Fix possible NULL pointer dereference in ovl_destroy_inode

[sunliming]

From: sunliming <sunliming@xxxxxxxxxx>

In the ovl_destroy_inode function, a variable reference oi->lowerdata_redirect
that might be NULL is directly freed. Add a non-null check, and only free
the space when it is not NULL.

Signed-off-by: sunliming <sunliming@xxxxxxxxxx>
---
 fs/overlayfs/super.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 60f0b7ceef0a..4b8b5fd4ab59 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -218,7 +218,7 @@ static void ovl_destroy_inode(struct inode *inode)
 	ovl_stack_put(ovl_lowerstack(oi->oe), ovl_numlower(oi->oe));
 	if (S_ISDIR(inode->i_mode))
 		ovl_dir_cache_free(inode);
-	else
+	else if (oi->lowerdata_redirect)
 		kfree(oi->lowerdata_redirect);
 }
 
-- 
2.25.1