From: Roman Kisel <romank@linux.microsoft.com>
Date: Wed, 8 Oct 2025 23:34:12 +0000 (-0700)
Subject: Drivers: hv: Check message and event pages for non-NULL before iounmap()
X-Git-Tag: v6.19-rc1~56^2~42
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=09406f2f8466fe44894f444943134a09c8519e4f;p=thirdparty%2Fkernel%2Flinux.git

Drivers: hv: Check message and event pages for non-NULL before iounmap()

It might happen that some hyp SynIC pages aren't allocated.

Check for that and only then call iounmap().

Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index e9e1edd751079..77da2d2113789 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -371,8 +371,10 @@ void hv_synic_disable_regs(unsigned int cpu)
 	 */
 	simp.simp_enabled = 0;
 	if (ms_hyperv.paravisor_present || hv_root_partition()) {
-		iounmap(hv_cpu->hyp_synic_message_page);
-		hv_cpu->hyp_synic_message_page = NULL;
+		if (hv_cpu->hyp_synic_message_page) {
+			iounmap(hv_cpu->hyp_synic_message_page);
+			hv_cpu->hyp_synic_message_page = NULL;
+		}
 	} else {
 		simp.base_simp_gpa = 0;
 	}
@@ -383,8 +385,10 @@ void hv_synic_disable_regs(unsigned int cpu)
 	siefp.siefp_enabled = 0;
 
 	if (ms_hyperv.paravisor_present || hv_root_partition()) {
-		iounmap(hv_cpu->hyp_synic_event_page);
-		hv_cpu->hyp_synic_event_page = NULL;
+		if (hv_cpu->hyp_synic_event_page) {
+			iounmap(hv_cpu->hyp_synic_event_page);
+			hv_cpu->hyp_synic_event_page = NULL;
+		}
 	} else {
 		siefp.base_siefp_gpa = 0;
 	}