ovl: check ERR_PTR() return value from ovl_encode_fh()

Another fix for an issue reported by 0-day robot. Reported-by: Dan Carpenter <[email protected]> Fixes: 8ed5eec ("ovl: encode pure upper file handles") Signed-off-by: Amir Goldstein <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]>
olifre · Feb 5, 2018 · 9b6faee · 9b6faee
1 parent 2aed489
commit 9b6faee
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c
@@ -108,6 +108,9 @@ static int ovl_d_to_fh(struct dentry *dentry, char *buf, int buflen)
 
 	/* Encode an upper or origin file handle */
 	fh = ovl_encode_fh(origin ?: ovl_dentry_upper(dentry), !origin);
+	err = PTR_ERR(fh);
+	if (IS_ERR(fh))
+		goto fail;
 
 	err = -EOVERFLOW;
 	if (fh->len > buflen)