Avoid calling memcpy() on NULL

base2bin() would call memcpy() on NULL for empty fsverity signatures.
This is undefined behavior, even if the length is 0.

(cherry picked from commit 6d3ce1c96833e896f082df81c727687da130f416)

1 files changed, 4 insertions, 2 deletions

diff --git a/lib/rpmfi.c b/lib/rpmfi.c
index 1f5ca7a20..d36263248 100644
--- a/lib/rpmfi.c
+++ b/lib/rpmfi.c
@@ -1626,8 +1626,10 @@ static uint8_t *base2bin(Header h, rpmTagVal tag, rpm_count_t num, int *len)
 	t = bin = xcalloc(num, maxlen);
 
 	for (i = 0; i < num; i++) {
-	    memcpy(t, arr[i], lengths[i]);
-	    free(arr[i]);
+	    if (arr[i]) {
+		memcpy(t, arr[i], lengths[i]);
+		free(arr[i]);
+	    }
 	    t += maxlen;
 	}
 	*len = maxlen;