--- a/sys/vfs/hammer2/hammer2_bulkfree.c
+++ b/sys/vfs/hammer2/hammer2_bulkfree.c
@@ -845,7 +858,20 @@
 	 * it's a problem if it does.  (Or L0 (4MB) for that matter).
 	 */
 	radix = (int)(bref->data_off & HAMMER2_OFF_MASK_RADIX);
-	KKASSERT(radix != 0);
+	/*
+	 * DF-2650: a radix of 0 means a 1-byte allocation, which cannot
+	 * exist on media.  On-disk corruption or a crafted image must not
+	 * panic an INVARIANTS kernel; skip the record instead of marking
+	 * a bogus fragment.
+	 */
+	if (radix == 0) {
+		kprintf("hammer2_bulkfree_scan: illegal radix-0 data_off "
+			"%016jx %016jx/%d\n",
+			(intmax_t)bref->data_off,
+			(intmax_t)bref->key,
+			bref->keybits);
+		return 0;
+	}
 	bytes = (size_t)1 << radix;
 	class = (bref->type << 8) | HAMMER2_PBUFRADIX;