From 7c30100c0047a0a3f489e28197cb641fc1a6f737 Mon Sep 17 00:00:00 2001
From: Mark Johnston <markj@FreeBSD.org>
Date: Sun, 15 Jan 2023 17:05:19 -0500
Subject: [PATCH] Avoid passing an uninitialized index to dsl_prop_known_index

Reported-by: KMSAN
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Akash B <akash-b@hpe.com>
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Sponsored-by: The FreeBSD Foundation
Closes #14397
---
 module/zfs/dsl_prop.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/module/zfs/dsl_prop.c b/module/zfs/dsl_prop.c
index d1c005909..57ff3b10d 100644
--- a/module/zfs/dsl_prop.c
+++ b/module/zfs/dsl_prop.c
@@ -123,7 +123,7 @@ dsl_prop_get_dd(dsl_dir_t *dd, const char *propname,
 		/* Check for a iuv value. */
 		err = zap_lookup(mos, dsl_dir_phys(dd)->dd_props_zapobj,
 		    iuvstr, intsz, numints, buf);
-		if (dsl_prop_known_index(zfs_name_to_prop(propname),
+		if (err == 0 && dsl_prop_known_index(zfs_name_to_prop(propname),
 		    *(uint64_t *)buf) != 1)
 			err = ENOENT;
 		if (err != ENOENT) {