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| author | Paolo Bonzini <pbonzini@redhat.com> | 2021-07-27 08:43:10 -0400 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-07-27 16:59:01 -0400 |
| commit | 8750f9bbda115f3f79bfe43be85551ee5e12b6ff (patch) | |
| tree | a61e5aaa7d209014be8a5f08a24712b2e7ce9e06 | |
| parent | 74775654332b2682a5580d6f954e5a9ac81e7477 (diff) | |
KVM: add missing compat KVM_CLEAR_DIRTY_LOG
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: 2a31b9db1535 ("kvm: introduce manual dirty log reprotect")
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | virt/kvm/kvm_main.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 0d732813fa80..d20fba0fc290 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4391,6 +4391,16 @@ 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) { @@ -4400,6 +4410,24 @@ 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; |