From e093b8b68af7c04d4dee770d3adf1d135643e395 Mon Sep 17 00:00:00 2001
From: Nathan Lynch <nathanl@linux.ibm.com>
Date: Tue, 28 Sep 2021 07:45:50 -0500
Subject: [PATCH] powerpc: fix unbalanced node refcount in check_kvm_guest()
Git-commit: 56537faf8821e361d739fc5ff58c9c40f54a1d4c
Patch-mainline: v5.16-rc1
References: stable-5.14.19
[ Upstream commit 56537faf8821e361d739fc5ff58c9c40f54a1d4c ]
When check_kvm_guest() succeeds in looking up a /hypervisor OF node, it
returns without performing a matching put for the lookup, leaving the
node's reference count elevated.
Add the necessary call to of_node_put(), rearranging the code slightly to
avoid repetition or goto.
Fixes: 107c55005fbd ("powerpc/pseries: Add KVM guest doorbell restrictions")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210928124550.132020-1-nathanl@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
arch/powerpc/kernel/firmware.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/firmware.c b/arch/powerpc/kernel/firmware.c
index c7022c41cc31..20328f72f9f2 100644
--- a/arch/powerpc/kernel/firmware.c
+++ b/arch/powerpc/kernel/firmware.c
@@ -31,11 +31,10 @@ int __init check_kvm_guest(void)
if (!hyper_node)
return 0;
- if (!of_device_is_compatible(hyper_node, "linux,kvm"))
- return 0;
-
- static_branch_enable(&kvm_guest);
+ if (of_device_is_compatible(hyper_node, "linux,kvm"))
+ static_branch_enable(&kvm_guest);
+ of_node_put(hyper_node);
return 0;
}
core_initcall(check_kvm_guest); // before kvm_guest_init()
--
2.26.2