From 19516b69ee41c9d3e239cb132c31fa9b13af2356 Mon Sep 17 00:00:00 2001
From: Richard Yao <richard.yao@alumni.stonybrook.edu>
Date: Fri, 14 Oct 2022 16:33:22 -0400
Subject: [PATCH] Fix potential NULL pointer dereference in lzc_ioctl()

Users are allowed to pass NULL to resultp, but we unconditionally assume
that they never do. When an external user does pass NULL to resultp, we
dereference a NULL pointer.

Clang's static analyzer complained about this.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14008
---
 lib/libzfs_core/libzfs_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/libzfs_core/libzfs_core.c b/lib/libzfs_core/libzfs_core.c
index 16bd9af1b..3fe65e665 100644
--- a/lib/libzfs_core/libzfs_core.c
+++ b/lib/libzfs_core/libzfs_core.c
@@ -235,7 +235,7 @@ lzc_ioctl(zfs_ioc_t ioc, const char *name,
 			break;
 		}
 	}
-	if (zc.zc_nvlist_dst_filled) {
+	if (zc.zc_nvlist_dst_filled && resultp != NULL) {
 		*resultp = fnvlist_unpack((void *)(uintptr_t)zc.zc_nvlist_dst,
 		    zc.zc_nvlist_dst_size);
 	}