Patch "arm/arm64: KVM: Fix ioctl error handling" has been added to the 4.4-stable tree

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

arm/arm64: KVM: Fix ioctl error handling

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:
arm-arm64-kvm-fix-ioctl-error-handling.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 <[email protected]> know about it.

From: "Michael S. Tsirkin" <[email protected]>
Date: Sun, 28 Feb 2016 17:32:07 +0200
Subject: arm/arm64: KVM: Fix ioctl error handling

From: Michael S. Tsirkin <[email protected]>

commit 4cad67fca3fc952d6f2ed9e799621f07666a560f upstream.

Calling return copy_to_user(...) in an ioctl will not do the right thing if there's a pagefault:
copy_to_user returns the number of bytes not copied in this case.

Fix up kvm to do

	return copy_to_user(...)) ?  -EFAULT : 0;

everywhere.

---
 arch/arm/kvm/guest.c   |    2 +-
 arch/arm64/kvm/guest.c |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

@@ -155,7 +155,7 @@ static int get_timer_reg(struct kvm_vcpu
 	u64 val;
 
 	val = kvm_arm_timer_get_reg(vcpu, reg->id);
-	return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id));
+	return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)) ? -EFAULT : 0;
 }
 
 static unsigned long num_core_regs(void)

@@ -186,7 +186,7 @@ static int get_timer_reg(struct kvm_vcpu
 	u64 val;
 
 	val = kvm_arm_timer_get_reg(vcpu, reg->id);
-	return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id));
+	return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)) ? -EFAULT : 0;
 }
 
 /**

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/vfio-fix-ioctl-error-handling.patch queue-4.4/arm-arm64-kvm-fix-ioctl-error-handling.patch queue-4.4/mips-kvm-fix-ioctl-error-handling.patch