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Commit 9bd10921 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Greg Kroah-Hartman
Browse files

KVM: add missing compat KVM_CLEAR_DIRTY_LOG 



commit 8750f9bbda115f3f79bfe43be85551ee5e12b6ff upstream.

The arguments to the KVM_CLEAR_DIRTY_LOG ioctl include a pointer,
therefore it needs a compat ioctl implementation.  Otherwise,
32-bit userspace fails to invoke it on 64-bit kernels; for x86
it might work fine by chance if the padding is zero, but not
on big-endian architectures.

Reported-by: Thomas Sattler
Cc: stable@vger.kernel.org
Fixes: 2a31b9db ("kvm: introduce manual dirty log reprotect")
Reviewed-by: default avatarPeter Xu <peterx@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7a94dfe5

virt/kvm/kvm_main.c

+28 −0
Original line number Diff line number Diff line
@@ -3570,6 +3570,16 @@ struct compat_kvm_dirty_log { 
	};

};



struct compat_kvm_clear_dirty_log {

	__u32 slot;

	__u32 num_pages;

	__u64 first_page;

	union {

		compat_uptr_t dirty_bitmap; /* one bit per page */

		__u64 padding2;

	};

};



static long kvm_vm_compat_ioctl(struct file *filp,

			   unsigned int ioctl, unsigned long arg)

{
@@ -3579,6 +3589,24 @@ static long kvm_vm_compat_ioctl(struct file *filp, 
	if (kvm->mm != current->mm)

		return -EIO;

	switch (ioctl) {

#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT

	case KVM_CLEAR_DIRTY_LOG: {

		struct compat_kvm_clear_dirty_log compat_log;

		struct kvm_clear_dirty_log log;



		if (copy_from_user(&compat_log, (void __user *)arg,

				   sizeof(compat_log)))

			return -EFAULT;

		log.slot	 = compat_log.slot;

		log.num_pages	 = compat_log.num_pages;

		log.first_page	 = compat_log.first_page;

		log.padding2	 = compat_log.padding2;

		log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);



		r = kvm_vm_ioctl_clear_dirty_log(kvm, &log);

		break;

	}

#endif

	case KVM_GET_DIRTY_LOG: {

		struct compat_kvm_dirty_log compat_log;

		struct kvm_dirty_log log;