Patch "KVM: s390: fix guest fprs memory leak" has been added to the 4.4-stable tree

Patch "KVM: s390: fix guest fprs memory leak" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    KVM: s390: fix guest fprs memory leak

to the 4.4-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:
     kvm-s390-fix-guest-fprs-memory-leak.patch
and it can be found in the queue-4.4 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 9c7ebb613bffea2feef4ec562ba1dbcaa810942b Mon Sep 17 00:00:00 2001
From: David Hildenbrand <dahi@linux.vnet.ibm.com>
Date: Fri, 22 Jan 2016 14:55:56 +0100
Subject: KVM: s390: fix guest fprs memory leak

From: David Hildenbrand <dahi@linux.vnet.ibm.com>

commit 9c7ebb613bffea2feef4ec562ba1dbcaa810942b upstream.

fprs is never freed, therefore resulting in a memory leak if
kvm_vcpu_init() fails or the vcpu is destroyed.

Fixes: 9977e886cbbc ("s390/kernel: lazy restore fpu registers")
Reported-by: Eric Farman <farman@linux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Eric Farman <farman@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/s390/kvm/kvm-s390.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1202,6 +1202,7 @@ void kvm_arch_vcpu_destroy(struct kvm_vc
 
 	if (vcpu->kvm->arch.use_cmma)
 		kvm_s390_vcpu_unsetup_cmma(vcpu);
+	kfree(vcpu->arch.guest_fpregs.fprs);
 	free_page((unsigned long)(vcpu->arch.sie_block));
 
 	kvm_vcpu_uninit(vcpu);
@@ -1516,12 +1517,14 @@ struct kvm_vcpu *kvm_arch_vcpu_create(st
 
 	rc = kvm_vcpu_init(vcpu, kvm, id);
 	if (rc)
-		goto out_free_sie_block;
+		goto out_free_fprs;
 	VM_EVENT(kvm, 3, "create cpu %d at %p, sie block at %p", id, vcpu,
 		 vcpu->arch.sie_block);
 	trace_kvm_s390_create_vcpu(id, vcpu, vcpu->arch.sie_block);
 
 	return vcpu;
+out_free_fprs:
+	kfree(vcpu->arch.guest_fpregs.fprs);
 out_free_sie_block:
 	free_page((unsigned long)(vcpu->arch.sie_block));
 out_free_cpu:


Patches currently in stable-queue which might be from dahi@linux.vnet.ibm.com are

queue-4.4/kvm-s390-fix-memory-overwrites-when-vx-is-disabled.patch
queue-4.4/kvm-s390-fix-guest-fprs-memory-leak.patch