This is a note to let you know that I've just added the patch titled powerpc: fix unbalanced node refcount in check_kvm_guest() to the 5.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: powerpc-fix-unbalanced-node-refcount-in-check_kvm_gu.patch and it can be found in the queue-5.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 128f472d95ec1e1df7abfb8192b61cb9374d72d5 Author: Nathan Lynch <nathanl@xxxxxxxxxxxxx> Date: Tue Sep 28 07:45:50 2021 -0500 powerpc: fix unbalanced node refcount in check_kvm_guest() [ 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@xxxxxxxxxxxxx> Reviewed-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx> Reviewed-by: Tyrel Datwyler <tyreld@xxxxxxxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210928124550.132020-1-nathanl@xxxxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/powerpc/kernel/firmware.c b/arch/powerpc/kernel/firmware.c index c7022c41cc314..20328f72f9f2b 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()