btrfs: fix crash/invalid memory access on fsync when using overlayfs

[firefly-linux-kernel-4.4.55.git] / fs / open.c

diff --git a/fs/open.c b/fs/open.c
index b6f1e96a7c0b331b3e5a5d9bb4c014c5c9edc54b..6a24f988d253dcf883e6fff1b851d33ebcd6ab50 100644 (file)
--- a/fs/open.c
+++ b/fs/open.c
@@ -995,14 +995,12 @@ struct file *filp_open(const char *filename, int flags, umode_t mode)
 EXPORT_SYMBOL(filp_open);
 
 struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt,
-                           const char *filename, int flags)
+                           const char *filename, int flags, umode_t mode)
 {
        struct open_flags op;
-       int err = build_open_flags(flags, 0, &op);
+       int err = build_open_flags(flags, mode, &op);
        if (err)
                return ERR_PTR(err);
-       if (flags & O_CREAT)
-               return ERR_PTR(-EINVAL);
        return do_file_open_root(dentry, mnt, filename, &op);
 }
 EXPORT_SYMBOL(file_open_root);