This is a note to let you know that I've just added the patch titled
kvm: fix usage of uninit spinlock in avic_vm_destroy()
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: kvm-fix-usage-of-uninit-spinlock-in-avic_vm_destroy.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Thu Dec 21 09:02:40 CET 2017
From: Dmitry Vyukov dvyukov@google.com Date: Tue, 24 Jan 2017 14:06:48 +0100 Subject: kvm: fix usage of uninit spinlock in avic_vm_destroy()
From: Dmitry Vyukov dvyukov@google.com
[ Upstream commit 3863dff0c3dd72984395c93b12383b393c5c3989 ]
If avic is not enabled, avic_vm_init() does nothing and returns early. However, avic_vm_destroy() still tries to destroy what hasn't been created. The only bad consequence of this now is that avic_vm_destroy() uses svm_vm_data_hash_lock that hasn't been initialized (and is not meant to be used at all if avic is not enabled).
Return early from avic_vm_destroy() if avic is not enabled. It has nothing to destroy.
Signed-off-by: Dmitry Vyukov dvyukov@google.com Cc: Joerg Roedel joro@8bytes.org Cc: Paolo Bonzini pbonzini@redhat.com Cc: "Radim Krčmář" rkrcmar@redhat.com Cc: David Hildenbrand david@redhat.com Cc: kvm@vger.kernel.org Cc: syzkaller@googlegroups.com Reviewed-by: David Hildenbrand david@redhat.com Signed-off-by: Radim Krčmář rkrcmar@redhat.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/svm.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1382,6 +1382,9 @@ static void avic_vm_destroy(struct kvm * unsigned long flags; struct kvm_arch *vm_data = &kvm->arch;
+ if (!avic) + return; + avic_free_vm_id(vm_data->avic_vm_id);
if (vm_data->avic_logical_id_table_page)
Patches currently in stable-queue which might be from dvyukov@google.com are
queue-4.9/kvm-fix-usage-of-uninit-spinlock-in-avic_vm_destroy.patch queue-4.9/inet-frag-release-spinlock-before-calling-icmp_send.patch queue-4.9/crypto-deadlock-between-crypto_alg_sem-rtnl_mutex-genl_mutex.patch