Patch "kvm: async_pf: fix rcu_irq_enter() with irqs enabled" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

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

    kvm: async_pf: fix rcu_irq_enter() with irqs enabled

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-async_pf-fix-rcu_irq_enter-with-irqs-enabled.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 bbaf0e2b1c1b4f88abd6ef49576f0efb1734eae5 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Wed, 26 Apr 2017 16:56:26 +0200
Subject: kvm: async_pf: fix rcu_irq_enter() with irqs enabled
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Paolo Bonzini <pbonzini@redhat.com>

commit bbaf0e2b1c1b4f88abd6ef49576f0efb1734eae5 upstream.

native_safe_halt enables interrupts, and you just shouldn't
call rcu_irq_enter() with interrupts enabled.  Reorder the
call with the following local_irq_disable() to respect the
invariant.

Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kernel/kvm.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -161,8 +161,8 @@ void kvm_async_pf_task_wait(u32 token)
 			 */
 			rcu_irq_exit();
 			native_safe_halt();
-			rcu_irq_enter();
 			local_irq_disable();
+			rcu_irq_enter();
 		}
 	}
 	if (!n.halted)


Patches currently in stable-queue which might be from pbonzini@redhat.com are

queue-4.4/kvm-async_pf-fix-rcu_irq_enter-with-irqs-enabled.patch
queue-4.4/kvm-async_pf-avoid-async-pf-injection-when-in-guest-mode.patch
queue-4.4/kvm-cpuid-fix-read-write-out-of-bounds-vulnerability-in-cpuid-emulation.patch