From 7c92a9c782970c168f12107eb5cf7816d4741710 Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Mon, 7 Apr 2025 11:35:25 +0100
Subject: [PATCH] copy: Fix crash when blkhash size is not a power of 2

nbdcopy: blkhash.c:105: init_blkhash: Assertion `is_power_of_2 (blkhash_size)' failed.

The check for this was wrong, resulting in a later assertion failure
instead of an error message.

Reported-by: Vera Wu
Fixes: https://issues.redhat.com/browse/RHEL-85513
(cherry picked from commit 6c6e0822c854e423d79bef87caf1c20c5bdb5eb5)
---
 copy/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/copy/main.c b/copy/main.c
index 76b09ded..613b9ede 100644
--- a/copy/main.c
+++ b/copy/main.c
@@ -220,7 +220,7 @@ main (int argc, char *argv[])
                      prog, "--blkhash", error, pstr);
             exit (EXIT_FAILURE);
           }
-          if (! is_power_of_2 (blkhash_size)) {
+          if (! is_power_of_2 (i64)) {
             fprintf (stderr, "%s: %s is not a power of two: %s\n",
                      prog, "--blkhash", &optarg[i+1]);
             exit (EXIT_FAILURE);
-- 
2.47.1